Avon NC - EFH Assessment

APPENDIX F
ESSENTIAL FISH HABITAT ASSESSMENT
in support of the permit application for

AVON VILLAGE BEACH NOURISHMENT
DARE COUNTY, NC

Prepared for:

Dare County Commissioners
US Army Corps of Engineers
National Park Service - Cape Hatteras National Seashore

For review by:
NOAA-National Marine Fisheries Service
NC Division of Marine Fisheries

Prepared by:
CZR Incorporated
4709 College Acres Drive Suite 2
Wilmington, NC 27403
Coastal Science & Engineering
P.O. Box 8056
Columbia, SC 29202
July 2021

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ESSENTIAL FISH HABITAT ASSESSMENT
in support of the permit application for

AVON VILLAGE BEACH NOURISHMENT
DARE COUNTY, NC

Prepared for:
Dare County Commissioners
US Army Corps of Engineers
National Park Service - Cape Hatteras National Seashore

For review by:
National Marine Fisheries Service
NC Division of Marine Fisheries

Prepared by:
CZR Incorporated
4709 College Acres Drive Suite 2
Wilmington, NC 27403

Coastal Science & Engineering
P.O. Box 8056
Columbia, SC 29202

July 2021

— THIS PAGE INTENTIONALLY LEFT BLANK —

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2525–Task 4–Appendix F] i Avon Village, Dare County, North Carolina

TABLE OF CONTENTS

1.0 INTRODUCTION AND PROJECT SETTING .................................................................................................... 1
2.0 FISHERIES COORDINATION ........................................................................................................................... 5
3.0 DESCRIPTION of ALTERNATIVES AND PROPOSED ACTION ..................................................................... 7
3.1 Additional Details of Applicant-Proposed Action (Alternative 3-Summer Construction) ....... 11
4.0 RESOURCE SURVEYS AND COORDINATION .............................................................................................. 21
5.0 EFH AND HABITAT AREAS OF PARTICULAR CONCERN (HAPC)
WITHIN PROPOSED PROJECT AREA OR VICINITY ................................................................................... 23
5.1 Potential EFH or EFH-HAPC within Project Impact Area and Fish Species Which Utilize Them .. 34
5.1.1 Estuarine Emergent Wetlands .................................................................................... 34
5.1.2 Submerged Aquatic Vegetation (SAV) and Seagrass ................................................. 34
5.1.3 Oyster Reef and Shell Banks ....................................................................................... 36
5.1.4 Estuarine Intertidal Flats ............................................................................................ 36
5.1.5 Sargassum and Sargassum Pelagic Habitat .............................................................. 36
5.1.6 Water Column ............................................................................................................. 37
5.1.6.1 Estuarine water column ............................................................................... 40
5.1.6.2 Marine water column ................................................................................... 40
5.1.7 Hard Bottom ............................................................................................................... 46
5.1.8 Artificial/man-made reefs ........................................................................................... 46
5.1.9 Primary and Secondary Nursery Areas (PNAs/SNAs) ................................................ 47
5.1.10 Unconsolidated/shallow subtidal bottom .............................................................. 47
5.1.11 Cape Hatteras shoals ................................................................................................. 47
6.0 POTENTIAL EFFECTS TO EFH, EFH-HAPC, OR LIFE STAGES OF ASSOCIATED MANAGED FISH ....... 51
6.1 EFH and HAPC ........................................................................................................................... 52
6.1.1 Sargassum ................................................................................................................... 53
6.1.2 Marine water column (includes ocean high salinity surf zone) ................................. 54
6.1.3 Hard bottom................................................................................................................ 58
6.1.4 Unconsolidated/shallow subtidal bottom (marine only) ......................................... 59
6.1.5 Cape Hatteras shoals/sandy shoals/offshore bars .................................................... 62
6.2 Potential Cumulative Effects of Proposed Project on EFH and HAPC .................................... 64
7.0 EFH CONSIDERATIONS SUMMARY .............................................................................................................. 67
8.0 EFH IMPACT SUMMARY ................................................................................................................................. 67

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[2525–Task 4–Appendix F] ii Avon Village, Dare County, North Carolina

LIST OF FIGURES

Figure 1.1 The project area for the nourishment project at Avon Village, Dare County (NC),
showing maximum limit of maintenance and proposed offshore borrow area
within state waters near
Cape Hatteras ......................................................................................................... 2
Figure 1.2 Aerial and ground photos showing Avon dunes and shoreline ............................ 3
Figure 1.3 Highway NC 12 flooding and washover at high tide along Avon .......................... 4
Figure 3.1 Monthly average wave climate at NDBC wave buoy Station 41025
at Diamond Shoals compared with wave climate at the
USACE-FRF at Duck and peak times for selected resource activities ................... 9
Figure 3.2 Construction progress using three hopper dredges and one suction cutter
dredge along the Nags Head Oceanfront in 2011 ............................................... 13
Figure 3.3 Types of land-based equipment .......................................................................... 14
Figure 3.4 Map of core locations for proposed Avon borrow areas ..................................... 14
Figure 3.5 Representative core photo log ............................................................................. 15
Figure 3.6 Representative core log........................................................................................ 16
Figure 3.7 GSDs for Avon native beach samples compared with
offshore samples to 10 ft ...................................................................................... 17
Figure 3.8 Illustration of the general changes to profiles after initial fill placement .......... 19
Figure 3.9 Natural dune growth along Nags Head after the 2011 beach nourishment ...... 19
Figure 5.1 Location of hard bottom, possible hard bottom, shipwrecks,
and artificial reefs in state and federal waters off North
Carolina- northern coast ...................................................................................... 31
Figure 5.2 A screen shot of SAFMC designated EFH-HAPC near proposed
project ................................................................................................................... 33
Figure 5.3 Submerged aquatic vegetation in the proposed project vicinity ....................... 35
Figure 5.4 Floating mat of Sargassum with associated small fish,
weedline/windrow of Sargassum, and drifts of Sargassum
on Caribbean island of Tobago ............................................................................ 38
Figure 5.5 Distribution of sensitive life stages of important fishery species in the Carolinas
across months of the year by aquatic type/location .......................................... 39
Figure 5.6 Depiction of Cape Hatteras marine water column dynamics ............................. 41
Figure 5.7 Dominant fish species caught in commercial landings per NCDMF ................... 43
Figure 5.8 All other sharks in commercial landings per NCDMF .......................................... 43
Figure 5.9 Dominant fish species observed during recreational angler intercepts
from 2004-2019 per NCDMF .................................................................................. 46
Figure 5.10 Offshore bathymetry from Mallinson et al. (2009) .............................................. 49
Figure 6.1 Characteristics of fish that makes them vulnerable to effects
from dredging processes ...................................................................................... 60

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2525–Task 4–Appendix F] iii Avon Village, Dare County, North Carolina

LIST OF TABLES

Table 3.1 Presence through year by month and major recruitment periods
of surf zone invertebrates in the South Atlantic Bight ........................................ 8
Table 5.1 Types of EFH by water regime and EFH/HAPC defined in
South Atlantic region and in North Carolina ...................................................... 25
Table 5.2 Life stage categories for managed species by geographic region within the
Project Area or near vicinity ............................................................................... 26
Table 5.3 EFH type and EFH/HAPC within the project vicinity or project
footprint for which impacts may occur .............................................................. 27
Table 5.4 Management history of designated EFH for highly migratory
species ................................................................................................................. 28
Table 5.5 EFH types and geographically defined HAPCs within proposed
project vicinity or footprint and potential impacts by activity ......................... 29
Table 6.1 Sediment setting velocities ................................................................................ 55

LIST OF ATTACHMENTS

A HOPPER DREDGE AND CUTTER HEAD DREDGE INFORMATION AND MITIGATION MEASURES
EXTRACTED FROM THE FINAL EFH ASSESSMENT FOR EMERGENCY BEACH FILL ALONG NC
HIGHWAY 12 IN RODANTHE, DARE COUNTY, NC 3 JULY 2013

LIST OF ABBREVIATIONS

ATV – all terrain vehicle
AVS – American Vibracore Services Co.
ASMFC – Atlantic States Marine Fisheries Council
ASSRT – Atlantic Sturgeon Status Review Team
BA – biological assessment
BO – biological opinion
BOEM – Bureau of Ocean Energy Management
CAHA – Cape Hatteras National Seashore
CAMA – Coastal Area Management Act
CBRA – Coastal Barriers Resources Act
CZMA – Coastal Zone Management Act
CSE – Coastal Science & Engineering, Inc.
CWA – Clean Water Act

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[2525–Task 4–Appendix F] iv Avon Village, Dare County, North Carolina

ca – circa
cal yr BP – calibrated years before present
cy – cubic yard
EA – environmental assessment
EEZ – exclusive economic zone
EFHA – essential fish habitat assessment
EIS – environmental impact statement
ESA – Endangered Species Act
FEMA – Federal Emergency Management Administration
FMP – fisheries management plan
FONSI – finding of no significant impact
GESAMP – Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection
HAPC – Habitat Area of Particular Concern
lf – linear foot/feet
MSFCA – Magnuson-Stevens Fishery Conservation and Management Act
NAVD – North American Vertical Datum of 1988
NCDCM – North Carolina Division of Coastal Management
NCDENR – North Carolina Department of Environment and Natural Resources
NCDEQ – North Carolina Department of Environmental Quality (formerly NCDENR)
NCDMF – North Carolina Division of Marine Fisheries
NCDOT–North Carolina Department of Transportation
NCDWR – North Carolina Division of Water Resources
NCWRC – North Carolina Wildlife Resources Commission
NDBC – National Data Wave Buoy
NEPA – National Environmental Policy Act
NOAA – National Oceanic and Atmospheric Administration
NMFS – National Marine Fisheries Service
NPS – National Park Service
OPR – Office of Protected Resources (NOAA)
pers comm. – personal communication
SARBO –South Atlantic Regional Biological Opinion
SEPA – State Environmental Policy Act
SERO – Southeast Regional Office (NMFS)
TAR – Tidewater Atlantic Research
USACE – United States Army Corps of Engineers
USFWS – United States Fish and Wildlife Service

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2525–Task 4–Appendix F] 1 Avon Village, Dare County, North Carolina

ESSENTIAL FISH HABITAT ASSESSMENT
in support of the NEPA documents prepared for

AVON VILLAGE BEACH NOURISHMENT, DARE COUNTY, NC

1.0 INTRODUCTION AND PROJECT SETTING

In compliance with Section 305(b) (2) of the Magnuson-Stevens Fishery Conservation and Management Act
(reauthorized by 1996 amendments), Dare County and the US Army Corps of Engineers (USACE) provide
this National Marine Fisheries Service (NMFS) Essential Fish Habitat Assessment (EFHA) in regards to the
proposed project, Beach Nourishment at the Village of Avon, Dare County, NC. The proposed project will
affect lands within and waters adjacent to portions of the Cape Hatteras National Seashore (National
Seashore) in front of the Village of Avon. Dare County will request a special use permit from the NPS to
authorize beach restoration activities within National Seashore jurisdiction and a Clean Water Act Section
404 permit from the USACE for the associated dredge and fill activities under their jurisdiction. The federal
actions include decisions whether or not, and under what conditions, to issue the county the permits it
has requested. Dare County contracted with Coastal Science & Engineering, Inc. (CSE) of Columbia, SC for
an assessment on the Avon shoreline erosion and a feasibility report on three potential alternatives to
address the erosion (short-, middle-, and long-term solutions) (CSE 2020). The middle-term
(approximately 5-year) solution was selected by the County. The state action includes a Section 401 water
quality certification from the Division of Water Resources and a major Coastal Area Management Act
(CAMA) permit from the Division of Coastal Management. Two consultants assisted CSE: Tidewater
Atlantic Research, Inc. (TAR) of Washington, NC for geophysical field surveys and CZR Incorporated (CZR)
of Wilmington, NC for preparation of documents in support of the proposed project (EFHA and the
Biological Assessment [BA]). Dare County, or its authorized agent, is responsible for all coordination
required to obtain needed State or Federal authorizations.

The southern limit of the Avon beach nourishment project is located about 1.6 miles north of the northern
limit of the Buxton beach restoration project permitted in 2015 and 2016 and completed in 2018 (SAW-
2015-01612; NPS-GOV16-5700-014; NCDCM 135-15; and NCDEQ 401 #15-1087). Dare County proposes to
renourish the Buxton project area, and the final permit application was submitted in July 2021 (SAW-2021-
01266). This EFHA is a mirror of the Buxton renourishment EFHA with the specifics of the Avon project in
place of those of Buxton. Similar to the two Buxton projects in many aspects, the Avon nourishment will
extend about 2.5 miles of the 3.4- mile beach in front of the village with the placement of approximately
1.0 million cubic yards (cy) of suitable sand dredged from a nearshore borrow area. Dune restoration
would also occur in conjunction with the proposed beach restoration for ~1.7 miles of the project in the
critically eroded area south of the Avon pier. The proposed offshore borrow areas for Avon beach and
dune nourishment are within state waters (Figure 1.1).

Along the Outer Banks of North Carolina, NC 12 connects all communities on Bodie, Hatteras, and
Ocracoke islands and serves as the only land-based evacuation route for all permanent and temporary
island residents when the predicted approach of severe weather determines an evacuation is necessary.
Emergency services also use NC 12 to access mainland hospitals and waste collection services for was te
disposal to the mainland.

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2525–Task 4–Appendix F] 2 Avon Village, Dare County, North Carolina

Low lying and/or narrow portions of NC 12 unprotected by substantial dunes are often affected by overwash
events during large storms and hurricanes, which deposit sand over portions of the road and/or cause actual
degradation of the road surface to the point of impassability; formation of new inlets is also not uncommon.
In these conditions, the NC Department of Transportation (NCDOT) initiates emergency repairs to alleviate
the hardship imposed by the closure of NC 12; therefore, repair and maintenance are almost continuous to
prevent permanent loss of access on Hatteras Island. Portions of the Village of Avon and NC 12 have been
inundated from storms more frequently over the past few years as sections of oceanfront dunes have
breached due to accelerated erosion. Four hurricanes in 2017, several March 2018 nor’easters, and
additional storms/hurricanes in 2019 and 2020 worsened the condition of the oceanfront dunes. Figure 1.2
illustrates recent conditions along the eroded oceanfront south of Avon Pier. Figure 1.3 shows tidal flooding
on Highway NC 12 and an active washover associated with an October 2019 nor’easter.

FIGURE 1.1. The project area for the nourishment project at Avon Village, Dare County (NC), showing maximum
limit of beach nourishment and proposed offshore borrow area within state waters near Cape Hatteras.

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2525–Task 4–Appendix F] 3 Avon Village, Dare County, North Carolina

FIGURE 1.2. [UPPER] Aerial photo looking south on 11 March 2021 showing loss of vegetated foredune along
the critically eroded section of Avon and extensive washover deposits landward of homes. Emergency dunes
constructed from washover sand front some properties. (Photo by D. Giles). [CENTER] Ground photo looking
south approximately 1,500 ft south of Avon Pier on 16 July 2020. (Photo by D. Giles). As recently as 2017 the
boardwalk in the foreground was fronted by a protective dune and continued south for 2,500 ft. [LOWER]
Ground photo showing pushed-up dune along oceanfront houses south of the pier. (Photo by T. Kana)

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2525–Task 4–Appendix F] 4 Avon Village, Dare County, North Carolina

FIGURE 1.3. Highway NC 12 flooding (upper) and an active washover at high tide (lower) 11-12 October
2019 along Avon. (Photos courtesy of Epic Shutter Photography).

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2403M–Task 4–Appendix F] 5 Avon Village, Dare County, North Carolina

2.0 FISHERIES COORDINATION

The Department of Commerce is the government branch that includes the National Oceanic and
Atmospheric Administration (NOAA) that oversees the National Marine Fisheries Service. Management
councils develop and amend management plans for approval/implementation by NMFS and design
research priorities. Although both the South Atlantic Fisheries Management Council (SAFMC) and the
Mid Atlantic Fisheries Management Council (MAFMC), in coordination with the Atlantic States Marine
Fisheries Commission (ASMFC), manage numerous fish stocks which may frequent the waters of the
Outer Banks, only those which have a federal Fishery Management Plan (FMP) have designated EFH or
Habitat Areas of Particular Concern (HAPC) within the EFH. The 1998 Comprehensive EFH Amendment
(SAFMC 1998) identified EFH/HAPC for most of SAFMC’s FMPs (Dolphin Wahoo FMP and EFH/HAPC for
this fishery were established in 2004). The FMPs identified areas as EFH with the specific purpose to
minimize adverse effects of fishing and to reduce or eliminate adverse effects from other non-fishing
activities identified in the FMPs. The HAPC designations do not confer any specific protective measures
but are designed towards conservation of habitat (MAFMC 2016). The Councils and NOAA fisheries lack
authority to regulate non-fishing activities, but per the Magnuson Stevenson Fishery Conservation
Management Act as amended (16 U.S.C.1855 § 305 (b)(2)) (MSFCMA), federal agencies must consult with
NOAA fisheries when they authorize, fund, or undertake activities which may affect EFH.

Fisheries managed by MAFMC occur in federal waters (3 to 200 miles from shore) and include 64 species
covered under seven FMPs, 14 other species have their own FMP, and include 50 forage species. In early
2019, one forage species was proposed for FMP inclusion along with a temporary limit on
development/expansion of directed fisheries for 16 others. For the southeast, also in federal wat ers,
SAFMC manages over 60 species which include the snapper-grouper complex, five species considered
coastal migratory pelagics, dolphin/wahoo, golden crab, spiny lobster, shrimp, coral, and Sargassum.
Over 40 other species are managed by NMFS as highly migratory species (e.g., tuna, billfish, large
coastal sharks, small coastal sharks, pelagic sharks, prohibited sharks, and smoothound shark
complex). Since 1942, ASMFC is the deliberative body of the Atlantic coastal states and coordinates the
management and conservation of 27 nearshore fish species in state waters (~3 miles from shore);
however, no official coordination with ASMFC is required. Either SAFMC or MAFMC also manage some
of those 27 species and many of those fish also utilize the EFH and/or HAPC addressed in this document.

The publication of the Fishery Ecosystem Plan of the South Atlantic Region in 2009 and its two
subsequent amendments (2010 and 2011) demonstrated that SAFMC fisheries management had
evolved from a habitat network to an ecosystem network, an approach that expanded the participation
of new stakeholders, coordinated regional efforts, and integrated food web dynamics to better achieve
broad essential habitat and fishery ecosystem conservation goals. In August 2015, NOAA published its
Fisheries Climate Science Strategy (Link et al. 2015). The December 2016 Policy Considerations for
South Atlantic Climate Variability and Fisheries and Essential Fish Habitats provided guidance from
SAFMC which supported the move to ecosystem based management and associated climate science
strategies to manage and assess cumulative effects and potential tradeoffs to achieve the most resilient
and sustainable fisheries. In 2017, MAFMC published the final Forage Base Omnibus Amendment, the
first rule in the Atlantic to list 16 forage species or species groups as ecosystem components in all the
MAFMC FMPs. This amendment prohibits development of new and the expansion of existing directed
commercial fisheries of these 16 forage species until more scientific information relating to potential

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2403M–Task 4–Appendix F] 6 Avon Village, Dare County, North Carolina

impacts of such directed commercial fisheries and impacts to existing fisheries, fishing communities,
and the marine ecosystem can be assessed. In August 2020, one of these 16 forage species, Atlantic
chub mackerel (Scomber colias), was formally added as a stock to the Atlantic Mackerel, Squid, and
Butterfish FMP under Amendment 21. This amendment to the FMP integrates catch limits and reporting
requirements for commercial fishing vessels in federal waters from Maine through North Carolina as
well as long-term conservation and management measures.

As more information is gathered about fishery ecosystems as a whole and ecosystem response to
climate driven changes, comprehension of the essential habitat needs of managed species deepens.
Research needs and adaptive decisions driven by climate science strategies will be identified through
NOAA’s Regional Action Plans. Currently, a final Regional Action Plan (RAP) has been published for the
Gulf of Mexico and a draft RAP for the southeast Atlantic was issued for public comment in September
2017 by the Southeast Fisheries Science Center (SEFSC) for the SAFMC region that includes North
Carolina (SEFSC 2017).

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[2403M–Task 4–Appendix F] 7 Avon Village, Dare County, North Carolina

3.0 DESCRIPTION OF ALTERNATIVES AND PROPOSED ACTION

Beach and dune erosion has worsened in recent years and accelerated the need for the proposed
action. Several alternatives were considered and dismissed for the Village of Avon restoration project
because they either would not be allowed under existing North Carolina regulations for the northern
coast (e.g. sand-retaining structures, seawalls), or due to environmental impacts, sediment quality, or
economics which are also dismissed for this beach nourishment project. Due to the level of s afety
required by dredge contractors to operate in the dynamic nearshore conditions common along the
Outer Banks, there have been seven beach nourishment projects on the Outer Banks permitted for
summer construction since 2011. Six of those in the northern Outer Banks were completed in the
summer (two at Nags Head and one each at Kill Devil Hills, Kitty Hawk, Southern Shores, and Duck).
The seventh, the Buxton beach restoration project, also anticipated completion by summer's end.
However, the project began in late June 2017 about one month later than planned and experienced
numerous construction delays due to hazardous wave climate in the borrow area near Diamond Shoals.
This drove construction through the summer into the fall with completion in Februar y 2018. A permit
for summer construction is preferred for the proposed Buxton beach renourishment for the same
reasons as before with the hope that wave climate delays of 2017 were an anomaly. Similar to the
Buxton renourishment project, the Avon beach nourishment project (also preferred summer
construction) proposes to restore not only a 2.5-mile length of Avon beachfront but also large sections
of degraded oceanfront dunes south of the Avon pier within that distance. The offshore borrow areas
shown on Figure 1.1 will be used for both the proposed initial dune and the beach restoration. The
proposed Avon nourishment project includes full evaluation of three potential alternatives:

1. No Action,
2. Beach Nourishment with Offshore Sand and Winter Construction
3. Beach Nourishment with Offshore Sand and Summer Construction (Proposed Action).

Preliminary alternatives analysis indicates that the No Action alternative would have the least impact
on the existing EFH-HAPC addressed in this assessment. The No Action alternative would result in the
most impact on the human environment (private structures and NC 12 would continue to be damaged
and flooded and cause interruptions and access issues. The second alternative would have minimal
impact on the EFH addressed in this assessment as construction would occur outside of either their
recruitment window (e.g., benthos), or their growth and reproduction window (e.g. some fish), or the
migratory window of many others. Due to normal winter wave climate, frequency of win ter storms
along the Outer Banks, and previous project experience, the winter construction window is likely to
prolong whatever impacts may occur with the potential for numerous mobilizations and
demobilizations, and prove most costly and impracticable. Without a nearby safe harbor, the dredge
operations would have to demobilize repeatedly to Virginia Beach (closest safe harbor for ocean going
dredges) both from the threat of storms and when the wave climate actually becomes unsafe; the
normal wave heights can become unsafe for the ocean dredges even on a clear sunny day. These
conditions would render the winter season alternative impracticable from both a safety and an
economic perspective. As before, preliminary alternatives analysis indicates the applicant preferred
alternative (Proposed Action) is likely to be most practicable alternative but also has the highest
likelihood of EFH impacts among the alternatives considered, especially if wave climate delays push
construction into fall benthic recruitment and increased fall presence of some fish.

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The Proposed Action, Avon Village Beach Nourishment, Dare County NC , is planned to begin summer
2022 with project completion two to three months later. The Proposed Action is described in detail
in the permit ap plication and includes project engineering and sediment specifics of the beach and
borrow areas. In support of the Proposed Action, a graph showing monthly average wave climate
was prepared which also shows representative peaks of certain biological resou rces/activities,
including diversity peak for demersal and pelagic fish (mid -September to mid-October) and
recruitment for some beach benthos (September) (Fig. 3.1 and Table 3.1 per Hackney et al. 1996).

TABLE 3.1 Presence through year by month and major recruitment periods of surf zone invertebrates in
the South Atlantic Bight (in Hackney et al. 1996).

P = present, H = peak abundance periods, R = recruitment periods
SPECIES J F M A M J J A S O N D
Coquina clams
Donax variablis
Ghost crabs
Ocypoda quadrata
Beach hoppers
Orchestoidea
Sand hoppers
Talorchestia
Worms
Polychaetes
Mole crabs
Emerita taploidea
P=present; H-peak abundance periods; R=recruitment periods
H,R
P,R
P
P,R
P
H
HH,R
H,RH,RPP
PP H,RH,R
HH
PP??
H
H,R
P
H,R
P
P,R
PP
PPPPPPPP
??P PPPPPPP
P,R P,R P,R P P P
H H P P
P P P P P P,R
MONTH OF THE YEAR
P P P P H H,R H,R H

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[2403M–Task 4–Appendix F] 9 Avon Village, Dare County, North Carolina

Alternative 3-Summer Construction would meet the goal to protect infrastructure, achieve the wider
oceanfront beach, and would meet the project purpose and need. This alternative is predicted to afford
protection for twice as long as Alternative 2-Winter Construction. The applicant-proposed action would
include placement of up to 1.0 million cubic yards of compatible sands (also dredged from the
proposed 250-acre offshore borrow area) along up to 13,200 ft (2.5 miles). While all of this length is
within National Seashore property, the entire project length is in front of the oceanfront of Avon Village.
The proposed dredging offshore and sand placement on the beach is projected to occur over a
~3-month period between June and August 2022.

Recognizing the serious concern for endangered and threatened species protection during summer
dredge operations along the ocean coast of the South Atlantic Region, certain monitoring and
mitigation measures would be implemented by the project owner (Dare County) and dredge contractor
in close coordination with resource agencies (e.g. PDCs and other guidance from the 2020 SARBO as
appropriate) and the NPS.
FIGURE 3.1. Graph showing the monthly average wave climate from 2003–2020 at NDBC Wave Buoy
Station 41025 at Diamond Shoals (NC) near Buxton and Avon compared with the wave climate at the USACE
Field Research Facility at Duck (NC). For some benthic species recruitment can be year round with a peak
in summer and fall (e.g., mole crab) and for other species there is also a winter-spring recruitment peak
(Wilber et al. 2009). Diaz (1980) found mole crab recruitment to peak in September following summer
spawning while Amend and Shanks (1999) found reproduction ended in late September. The criteria for
safe dredging apply to hopper dredge operations using ocean-certified equipment per informal guidance
by dredging companies. Operations decisions involve numerous additional factors: wave period, sea state,
pumping distance, size of dredge, and sediment characteristics. Suction cutterhead dredges generally
cannot operate safely in waves >3 ft (USACE 2010). [Source: NDBC]

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National Seashore biologists closely monitor shore bird and turtle nesting activities along the National
Seashore and establish closure areas when certain species are present and actively nesting. Fewer
shorebirds nest in the Avon project area compared to the Buxton project area; however, one least tern
nest and chick was observed in 2014 but none since. Shorebirds do rest and forage on the Avon beach
every year, and loggerhead sea turtle nests are usually documented on the Avon beach every year. After
informal interagency consultation with USFWS, NCWRC, and NPS for the 2017/2018 Buxton project,
Dare County proposed to minimize or mitigate impacts to nesting shorebirds and sea turtles and
marine mammals by the following measures which would also guide the Avon restoration project:

 Time construction activities to avoid active nesting areas to the extent practicable.
 Configure the fill sections to avoid placement on the dry sand beach in the vicinity of any
designated bird closure areas; placement would occur seaward of mean low wate r for
limited sections of the project.
 Monitor both sides of the shore pipe each night during construction for signs of turtle
activity.
 Daily sea turtle nesting surveys initiated by 1 May through end of project.
 USFWS- and/or NCWRC-authorized personnel will relocate all sea turtle nests that may
be affected by construction or sand placement ahead of construction to minimize
impacts to sea turtles. All relocated nests must be moved before 0900 the morning
following deposition to a secure setting meeting criteria to optimize hatch. Nest
relocations will cease as project segments are completed unless other factors threaten
successful hatch. All nests will be marked and avoided.
 Use special lights for turtles as recommended by USFWS and, per the 2020 SARBO, Florida
Fish and Wildlife Conservation Commission, and subject to conformance with OSHA
minimums for work safety.
 Maintain a minimum back beach buffer of the order 50-ft (no work area) between the
foredune and active nourishment area to avoid disturbance of incipient vegetation or
potential nesting areas.
 Maintain certified and NMFS/OPR-approved onboard protected species observers (PSOs)
with authority to stop work as deemed necessary by current ESA protocols, the 2020
SARBO, and/or standard conditions of the any biological opinion (BO) issued for the
project. Optional measures suggested to mitigate adverse effects will be fully considered.
 Trawl ahead of hopper dredges (non-capture trawling) to mobilize any sea turtles or
Atlantic sturgeon that may be resting in the surficial sediments of the borrow areas.

A goal of summer dredge operation is to accomplish the work at the largest volume possible in the
shortest time, so as to provide the greatest project longevity within the fiscal limitations of the avai lable
County funds. A project of ~1.0 million cubic yards can be constructed in two to three months in the
summer; however, based on recent experience at Buxton, wave climate is critical to the timeline, even
in the summer. Typically, projects at the scale of Buxton and Avon require two or more landing points
for the submerged pipeline. The sand slurry is pumped via the submerged pipeline to shore, then runs
parallel to the beach by way of “shore pipe”. Work proceeds north or south for a distance of 3,000-4,000
ft (typical) until that section of the project is complete. Then the shore pipe is removed and used to
build the next section in the opposite direction until complete. Avon (Fig 3.2) would likely be completed
in four discrete sections, working around the clock due to the high cost and number of personnel
required for the operation of ocean certified dredges. It is not practical or cost -effective to suspend

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operations for several weeks and restart the project due to the large amount of specialized equipment
needed for efficient and successful completion (Fig 3.3). Suspension of work for several weeks would
result in remobilization costs or high standby costs per day (order of $150,000-200,000) with
concomitant reduction in the volume that can be dredged under a fixed budget.

Fill sections can be modified to avoid placement landward of the low tide line for limited distances so
as to place active construction as far as possible from nest closure areas. Such a configuration would
leave a swale between the nourishment berm and the native beach. After construction is finished and
all equipment removed, autumn storms would be expected to overtop the nourishment berm and drive
sand into the swale. This procedure was used at Nags Head to avoid placing sand under condemned
houses that were positioned in the active swash zone (CSE 2012). It is not practical or advisable to leave
gaps in the project, given the anticipated cross-shore dimensions. Bulges in the fill adjacent to gaps
potentially produce accelerated erosion of unnourished sections. For similar reasons, the ends of the
project would incorporate long taper sections (order of 1,000–1,500 ft).

As sections are completed, a 1,000-4,000 ft length of shore pipe remains in place for a 1–2 week period.
The connection points every 40 ft must remain exposed for inspection for leaks by the dredgers, but
numerous sand ramps will be placed over the pipe for vehicles and beach goers. The duration of time
that the shore pipe would be strung out the maximum distance alongshore (~4,000 ft) would be a few
days. As soon as the section volume is in place, the shore pipe would be removed and the nourishment
berm graded to final contours with nearly all construction activity ceasing in that section. To minimize
ingress of heavy equipment along the beach at night, unused pipe sections would be pre-positioned by
loaders during daylight hours near the active work area for adding as needed during the night shift.
This would also confine lighting to the ~300 ft active work area each night.

Dare County proposes these monitoring and mitigation measures based on consultation with USFWS,
NMFS, and NPS officials, experience from the Buxton restoration project, and experience with Northern
Outer Banks nourishment projects.
3.1 Additional Details of Applicant-Proposed Action (Alternative 3-Summer Construction)

In addition to what has been described above, the applicant-proposed action (see Figure 1.1) includes
the following items:

1) All sediment placed on the Avon project beach would be compatible with the native beach.
The beach fill sand would be dredged from the proposed borrow areas located about 2 miles
offshore of Avon from within an unnamed sand ridge (see Fig 1.1). The borrow areas are south
of Kinnakeet and Wimble shoals. Geotechnical investigations were conducted in March 2021
within the proposed borrow area to identify sufficient quantities of beach compatible material
(≥90% sand) and determine presence of cultural resources or hard grounds. Figure 3.4 shows
a map and details of the cores obtained within the proposed borrow areas (see Fig 1.1).

Figures 3.5 and 3.6 show an example core photo log and core log from the center of the
proposed borrow areas. Figure 3.7 shows a preliminary comparison of the grain-size
distribution along the subaerial beach and borrow areas (composited samples in the upper 6–
10 ft of section). The proposed borrow area for the nourishment is an unnamed sand ridge

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exposed to high wave energy in water depths between 40 to 50 ft with negligible fine grained
material present (e.g., mud or organics) (CSE 2021). Geotechnical data within the proposed
borrow areas confirm the sediments are beach compatible and exceed North Carolina state
standards for similarity with the native beach (CSE 2021). A high density of 15 borings (~1 per
20 acres) demonstrates general uniformity of sediments in the upper 10 ft of substrate in
Borrow Area 1 and 6 ft in Borrow Area 2. Cultural resource data was collected and the results
are provided in the project Environmental Assessment – Appendix G.

2) The proposed work would use either an ocean certified hopper dredge (with pump -ashore
capabilities) and/or a hydraulic pipeline cutterhead dredge (cf. Fig 3.2) to excavate and pump
the material from the proposed offshore borrow areas to the sand placement area. The most
feasible and safe method for excavation is anticipated to be via hopper dredge during summer
months when wave energy at the borrow site is within threshold criteria for safest and most
optimal operations (see Fig 3.1). The project area is exposed to the highest waves along the
East Coast (Leffler et al. 1996) and is situated approximately 105 miles from the nearest safe
harbor at Little Creek Virginia. Ocean-going dredges, which can legally operate offshore,
generally have drafts which exceed the navigation channel depth or actual depth at Oregon
Inlet (~30 miles away) or Hatteras Inlet (~25 miles away, extra distance required to navigate
around Diamond Shoals for safe passage).

3) Once sand has been pumped to the site, heavy equipment typically used in beach fill
placement operations (i.e., bulldozers, front end loaders, excavators) would be used to fine
tune the design beach profile; other support vehicles (i.e., ATVs, trucks) would also d rive on
the beach (see Fig 3.3). Operations at the active beach construction site would be around the
clock seven days a week until completion, the active beach discharge point would be fenced
to protect public safety, and land-based personnel would work within the beach construction
zone to ensure compliance with conditions and restrictions of the applicable state and federal
permits. Staging areas would be used to store additional shore pipe, fuel, mobile on-site
office, and other necessary equipment. Locations of any staging areas and two anticipated
access points for support vehicles and heavier equipment would be coordinated with the NPS
and the Village of Avon, as necessary.

4) The duration of construction is expected to be ~2–3 months assuming operations are
permitted during summer months and weather/wave climate is conducive. Safe harbor
interruptions, which may be expected but are not quantifiable, are not included in the 3-month
construction estimate. Production for a 4.6 million cubic yards project at Nags Head, North
Carolina (~50 miles north of the Avon project site) was ~3.8 million cubic yards in three months
between 27 May and 27 August 2011 using one large hopper dredge (~6,000 cy capacity) and
one suction cutterhead dredge (for ~1.5 months), and ~0.8 million cubic yards in two months
between 27 August and 27 October using two smaller hopper dredges (~3,000 cy capacity each)
(CSE 2012). Low production rates for the latter 20 percent of the Nags Head project reflect a
high frequency of no-work days associated with high wave events in September and October.
Hurricane Irene impacted the Nags Head project on 27 August 2011.

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FIGURE 3.2. Three hopper dredges and one suction cutterhead dredge (inset photos) were used to construct the
Nags Head (NC) beach nourishment project (24 May to 27 October 2011). Image shows nourishment construction in
progress working south to north toward Outer Banks Pier in south Nags Head. Note the completed sections at the
top of the image which were pumped ashore via a more northerly pipeline corridor. [Photos by CSE and Great Lakes
Dredge & Dock Co.].

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FIGURE 3.3. Types of land-based support equipment generally required for beach nourishment
construction. [Photo annotations courtesy of J Lignelli and First Coastal Corp of New York.]

FIGURE 3.4. Map of core locations and representative statistics for the proposed Avon borrow areas.

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FIGURE 3.5. Example core photo log for one of the 10-ft borings (AV-27) obtained by subconsultant American Vibracore
Services (AVS) in April 2021.

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FIGURE 3.6. Core log for AV-27 showing the lithology, sample intervals, and mean grain sizes.

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FIGURE 3.7. Composite grain size distributions (GSDs) for cores in Borrow Area 1 (to 10 ft) and Borrow Area 2 (to 6 ft) for the
proposed Avon project. The comparison is against a composite of native beach samples along Avon.

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5) On a given day, the typical impact area along the beach in the project area would average
~1,000 linear feet. Project areas outside the active work area would remain open to the
public, subject to NPS natural resource protection, management, and policy. As sections of
the project are completed, the nourished area would be reopened immediately to the public
as appropriate. Sections of shore pipeline extending up to ~4,000 linear feet along the beach
would be left in place along the completed berm. Sand ramps would be placed over the
pipeline for vehicle and pedestrian access to and from the beach every 100–200 feet (ft). The
pipeline would be monitored nightly while in place to detect any turtle activity in the p roject
area and to insure no turtles are stranded landward of the pipeline. Upon completion of a
section of the project, the shore pipeline would be removed and relocated to a new pump-
out point and shore pipe extended along the beach as the subsequent sections are
completed. Thus, the shore length over which pipe extends during construction would vary
from ~100 ft to ~4,000 ft. Resource closure areas designated by NPS biologists before or
during construction would be bypassed or avoided by shifting construction as far seaward as
practicable to minimize impacts and maintain acceptable no work buffers near closure areas.
Close coordination between NPS personnel and contractors would be maintained
throughout the construction of the project.

6) Loaders would remove and relocate the pipeline and bulldozers would shape the
nourishment berm into its final grades and slopes above mean high water. The seaward slope
cannot be controlled accurately, but the likely intertidal beach slope for the nourished beach
at the time of construction would be ~1 on 15 based on experience in similar settings. The
constructed berm is expected to adjust rapidly to slopes and morphology typical of the surf
zone, including low-tide bars and troughs formed within weeks in response to varying wave
action. During fall months, the project area is subject to frequent high energy wave events
associated with minor extra-tropical storms (“northeasters”). The berm elevation of the
nourished beach is expected to be lower than the typical wave uprush limit during
northeasters and be overtopped periodically within months of project completion. Washover
deposits would shift sand landward to higher elevations near the foredune and shift sand into
shallow water. Figure 3.8 illustrates the general adjustment of a beach nourishment project
from the initial placement berm to the equilibrated profile. Figure 3.9 shows natural buildup
of the foredune over sand fencing placed at the toe of the foredune one year and three years
after construction of the Nags Head project. No dune planting or sand fencing were included
in those project plans.

7) The offshore borrow areas would be excavated to a maximum depth of 10 ft in Borrow Area 1
and 6 ft in Borrow Area 2 below existing grade. If hopper dredges are used, excavations would
leave undisturbed areas in close proximity to dredged corridors. High wave energy is
expected to rapidly eliminate irregularities in the borrow area topography and promote
mixing of exposed sands which underlie the removed sediments. The anticipated borrow
areas contain potential sand resources totaling ~3.4 million cubic yards. The maximum
project volume to be removed would be less than 30 percent of the sand resources in the
designated area. Upon adjustment, the average depth over the designated borrow areas is
expected to increase by ~3 ft to an average depth in the range ~40–50 ft below mean sea level.
The excavations over a natural ridge are not expected to leave deep holes.

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FIGURE 3.8. General changes to profiles after initial fill placement. The dry sand beach feeds sand via winds and washovers to the
dune line while a portion of the fill shifts into deeper water and reestablishes the topography of the inshore zone. (Source ©CSE)
FIGURE 3.9. Natural dune growth along south Nags Head (NH Station 855+00) after the 2011 nourishment project. [UPPER] 11 June
2012 locality in Nags Head (NC) seven months after nourishment. [LOWER] 5 June 2014 same locality two years and seven months
after nourishment. (From CSE 2014)

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4.0 RESOURCE SURVEYS AND COORDINATION

Coastal Science and Engineering conducted baseline, control, inshore geotechnical surveys, and
sediment compatibility analyses; TAR conducted geophysical investigations (magnometer and shallow
seismic profiles) and cultural resource analyses within the proposed offshore borrow areas. These
surveys confirm a general uniformity of sediment quality and compatibility with the beach and ensure
that the proposed project will not adversely encounter or impact hard bottom or cultural resources.
Data from these surveys will be coordinated with all appropriate agencies (e.g., NMFS, USFWS, USACE,
NCDMF, NCDCM, and NCWRC). Cultural resource survey results are detailed in Environmental
Assessment – Appendix G.

In September 2020, NPS issued a draft Environmental Impact Statement (DEIS) to identify the best
strategy and framework for streamlined Special Use permitting for future beach nourishment activities
projected to occur within the Seashore over the next 20 years. The final EIS was published in March
2021 (NPS 2021a) and Record of Decision issued in May 2021 (NPS 2021b). Prior to any construction of
the proposed Avon project, NPS will determine if the project meets the final NPS framework identified
in their document for issuance of a US Department of Interior Special Use Permit (SUP) for the
placement of sand on the Avon beach and dunes within the National Seashore boundary. If so, Dare
County will then coordinate with state and federal agencies to obtain the following authorizations:

1. North Carolina Division of Coastal Management (CAMA) Major Development Permit and
North Carolina Division of Water Resources (NCDWR) Section 401 of the Clean Water Act
Certificate (PL 92-500). As required by the State Environmental Policy Act (SEPA) of North
Carolina, the North Carolina Department of Administration’s State Clearing House will
coordinate state agency review of environmental documents prepared for the Proposed
Action.

2. Department of the Army Section 404 of the Clean Water Act and Section 10 of the Rivers
and Harbor Act of 1899 permits. These USACE permits will ensure that the proposed action
complies with Section 7 of the Endangered Species Act of 1973 (PL 93-205), as amended,
Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA), Section 106 of
the National Historic Preservation Act (i.e., cultural resources), Coastal Zone Management
Act (CZMA), Coastal Barrier Resources Act (CBRA), and other NEPA environmental
requirements.

No work will be initiated until these state and federal authorizations have been issued and all work will
comply with all conditions and restrictions found within these permits.

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5.0 EFH AND HABITAT AREAS OF PARTICULAR CONCERN (HAPC) WITHIN PROPOSED PROJECT
AREA OR VICINITY

The MSFCMA defines EFH as “all waters and substrates necessary to fish for spawning, breeding, feeding, or
growth to maturity” and may include habitat for individual species or an assemblage of species so
designated by regional fishery management councils. The MSFCMA also requires these regional councils to
develop and periodically amend, a Fishery Management Plan (FMP) for each resource or species and to
identify any Habitat Areas of Particular Concern (HAPC) within an EFH. The stated intent of the EFH
provisions in the MSFCMA is that EFH reflect only the important habitats and not the entire range of a species
or assemblage (NMFS 2017). Not only must any HAPC be within an EFH, the HAPC must meet one of four
criteria based on either ecological function, habitat sensitivity to human degradation, human development
activities stresses, or rarity.

The FMP amendments of SAFMC and MAFMC identify numerous types of EFH and locations of HAPC (Table
5.1). Table 5.2 shows those fish species managed by the SAFMC/MAFMC and their association with the
categories of Table 5.1 EFH and HAPC in the project vicinity.

On a state level, as mandated by a 1997 state law, the North Carolina Marine Fisheries, Environmental
Management, and Coastal Resources commissions adopted the North Carolina Coastal Habitat Protection
Plan (CHPP) in December 2004 and published the document in January 2005 (Street et al. 2005). The
purpose of the CHPP was long-term enhancement of coastal fisheries associated with coastal habitats. It
provided a framework to protect and restore habitats deemed critical to North Carolina coastal fisheries
updated on a five-year basis. In December 2010, with the addition of a fourth commission (North Carolina
Wildlife Resources) the second iteration of the CHPP was published to update the latest scientific
information on the condition, threats, and function of these habitats (Deaton et al. 2010); the most current
CHPP was published in August 2016 (NCDEQ 2016a,b). The CHPP identifies six types of these habitats: shell
bottom, sea grasses, wetlands, hard bottoms, soft bottoms, and the water column; these six habitats also
occur within, or overlap, some EFH habitats. In addition, in 2005, the North Carolina Wildlife Resources
Commission (NCWRC) developed the North Carolina Wildlife Action Plan, a comprehensive planning tool to
conserve and enhance the fish and wildlife species of the state and their habitats (no plants are included);
this tool was updated in 2015 (NCWRC 2015).

While all the EFH types occur in waters of the southeastern United States, and many occur in North Carolina
waters, only a few occur in the immediate project vicinity (within 2 miles) or the project area itself. The entire
~677-acre project area includes the dry beach, intertidal and subtidal surf zone, nearshore area, and the
entire marine water column between the borrow areas and the intertidal beach.

Location of habitats utilized by managed fish (or their prey) will change in response to concomitant shifts in
temperature, nutrients, ocean currents, and other ecosystem dynamics as the habitats and food
webs/forage base also adapt to those shifts. Habitats may shrink, disappear, or expand in the future and
while the pace of change is unpredictable it is currently faster in higher lati tudes. Some shifts are already
evident in the range, abundance, and distribution of Atlantic and Gulf of Mexico species (e.g., black sea bass
have spread north, lobster migration happens up to a month earlier, shrimp nursery area losses in
Louisiana), and in larger scale effects (e.g., ocean acidification, temperature rise and global coral decline)
and observed changes in ocean currents (Atlantic meridional overturning circulation, or AMOC, declined by
15 percent and a northward shift in the Gulf Stream as evidenced in Caesar et al. 2018), and by controversy

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[2403M–Task 4–Appendix F] 24 Avon Village, Dare County, North Carolina

about natural decadal variability vs anthropogenic accelerants of variable circulation (Chen and Tung 2018;
Latif et al. 2019).

Table 5.1 shows the categories of EFH and EFH/HAPC for managed species that were identified in the
applicable FMP or Amendments. In general, EFH/HAPC include high value intertidal and estuarine habitats,
offshore areas of high habitat value or vertical relief, and habitats used for migration, spawning, and rearing
of fish and shellfish. Due to characteristics of the proposed nourishment project location/vicinity where only
estuarine and marine environments occur, palustrine and freshwater EFH are not included in other tables
or in additional analyses.

Table 5.2 lists the federally managed fish species for which Fishery Management Plans (FMPs) have been
developed by the South Atlantic Fishery Management Council (SAFMC) and/or the Mid -Atlantic Fishery
Management Council (MAFMC) and which may occur in the project area waters or vi cinity. In addition, the
table shows EFH by life stage category for those fish species with designated EFH. Fish species which
utilize habitats shown in Table 5.1 and occur in the water bodies of NC in some life stage (Table 5.2) require
special consideration to promote their viability and sustainability. The habitats and HAPC for species
managed by the Atlantic States Fishery Management Council (ASFMC) and EFH and HAPC for SAFMC -
managed species are shown in Table 5.3 along with the species for which a FMP has been developed and
the species with ASFMC strategies and management goals. The management history for Highly Migratory
Species is shown in Table 5.4. The potential effects of the proposed project on species and habitats are
summarized in Table 5.5; for the purposes of this analysis, project vicinity is within 2 miles and the project
footprint includes the dredged borrow area s, the pipeline footprint, staging area footprint on the beach,
and the sediment placement area. Section 6.0 of this document co ntains more details about those
habitats or species potentially affected by the proposed project (either a Y or W shown in the Impact
Activity column of Table 5.5).

Figure 5.1 shows the hard bottom, possible hard bottom, shipwrecks, and artificial reefs i n state and
federal waters of the North Ca rolina coast near the Village of Avon as depicted in NCDEQ (2016a), the most
recent version of North Carolina’s Coastal Habitat Protection Plan. Geotechnical studies of the proposed
borrow areas including ~12 borings up to 10 ft long and geophysical surveys for the project by TAR confirm
there is no hard bottom in the borrow areas. Previous surveys conducted or reviewed as part of the NOAA
Southeast Area Monitoring and Assessment Program (SEAMAP) indicate that the nearest offshore
hardbottom habitat is ~2 miles northeast of th e proposed project area. Prior to any placement of sand on
the targeted beach at Avon, remote sensing (i.e., shallow seismic, magnetometer and side scan surveys)
will delineate any potential cultural resources such as wrecks and their associated habitat. All interim
and final survey data will be coordinated and provided to representatives of the NMFS and North Carolina
Division of Marine Fisheries (NCDMF). Current NC Coastal Resource Commiss ion (CRC) rules discourage
dredging activities within a 1,640 -foot buffer of significant biological communities, such as high relief hard
bottom areas [T15A NCAC 07H .0208(b)(12)(A)(iv)]. Under this rule, “high relief” is defined as greater than
or equal to ~1.7-feet per ~16 feet of horizontal distance. Because reef fishes derive a significant portion of
their nutritional requirements within a 500 m “halo” of exposed har d bottom Lindquist et al. (1994 ), the
sand dredging buffer around hard bottom areas (including those periodically buried with thin, ephemeral
sand layers) was recommended by the DCM appointed Ocean Policy Steering Committee (DCM 2009).
Appropriate avoidance buffers would surround any hardbottom features or cultural resources identified
and mapped within the project area.

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TABLE 5.1. Types of Essential Fish Habitat (EFH) by water regime and EFH-HAPC defined in the south Atlantic region and in
North Carolina.

EFH TYPES BY REGIME GEOGRAPHICALLY DEFINED EFH-HAPC
Palustrine Areas Area - Wide

Unconsolidated bottom/aquatic beds Sargassum habitat (pelagic and benthic)
Tidal forest Hard bottoms
Tidal freshwater Hoyt Hills
State-designated areas of importance
Estuarine Areas All coastal inlets
Hermatypic coral habitat and reefs
Subtidal/intertidal non-vegetated flats Council-designated Artificial Reef Special
Emergent wetlands Management Zones (SMZ)
Estuarine scrub / shrub (mangroves)
Water column North Carolina
State-designated PNAs and SNAs
Unconsolidated bottom Bogue Sound
Oyster reefs and shell banks Pamlico Sound at Hatteras/Ocracoke islands
Submerged aquatic vegetation (SAV) New River
Coastal inlets The Ten Fathom Ledge
High salinity bays, estuaries, and Big Rock
seagrass habitat Sandy shoals at capes (Hatteras, Lookout, Fear)
The Point
Marine Areas Primary and Secondary Nursery Areas
Cape Lookout South Spawning SMZ
Unconsolidated bottom/aquatic beds
Artificial / manmade reefs
Coral reefs
Live/hard bottom
Sargassum
Water column
Emergent wetlands
Submerged aquatic vegetation (SAV)
Continental shelf currents/Gulf Stream
Ocean high salinity surf zones
Sandy shoals of capes and offshore bars
Coastal inlets
Offshore habitats used for spawning
and growth to maturity

Table 5.1 Notes:
EFH identified in FMP Amendments for SAFMC and MAFMC. Geographically defined HAPC are identified in FMP
Amendments affecting the south Atlantic area. The EFH for species managed under NMFS Billfish and Highly
Migratory Species generally falls within the marine and estuarine water column habitats designated by the
Councils. Information in this table was derived from Appendices 4 and 5 of NMFS 2010 and SAFMC EFH and HAPC
designations from https://safmc.net/wp-content/uploads/2016/06/EFH20Table.pdf and https://safmc.net/wp-
content/uploads/2016/06/EFH-HAPC20Table.pdf.

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TABLE 5.2. Life stage categories for managed species by geographic region within the Project Area or near vicinity (as shown
on NOAA/NMFS EFH mapper, depicted in figures of Final Amendment 10 to 2006 consolidated HMS, or described in various
management amendments). For some species, paucity of information results in all life stages combined into the ALL category.
Note: — = life stage category not shown on EFH mapper; N = species not shown on EFH mapper for this life stage category; Y =
species shown on EFH mapper for this life stage category. Some species with no life stage categories shown as EFH in the
project area are included in table due to EFH in proximity and footnoted at the bottom of the table.

Eggs Larvae
Spawning,
eggs &
larvae
Neonate Neonate/
YOY Juvenile Adult ALL
Common name Latin name
*Atlantic butterfish Peprilus triacanthus N N ———Y Y
*Atlantic mackerel a Scomber scrombus N N ———N N
*Bluefish Pomatomus saltatrix N N ———Y Y
*Longfin inshore squid b Doryteuthis (Amerigo) pealeii N ————N N
*Scup Stenotomus chrysops N N ———Y Y
*Spiny dogfish Squalus acanthias —————N Y
*Summer flounder Paralichthys dentatus N Y ———Y Y
Spiny lobster Panulirus argus ———————Y
Snapper Grouper ———————Y
**Coastal migratory pelagics ———————Y
Albacore tuna Thunnus alalunga —————Y N
Bluefin tuna Thunnus thynnus ——Y ——Y Y
Yellowfin tuna Thunnus albacares ——N ——Y Y
Atlantic sailfish Istiophorus platypterus ——N ——Y Y
Blacktip shark Carcharhinus limbatus ———N —Y Y
**Sandbar shark Carcharhinus plumbeus ———Y Y Y Y
Scalloped hammerhead shark Sphyrna lewini ———N N Y Y
Spinner shark Carcharhinus brevipinna ————Y Y Y
Tiger shark Galeocerdo cuvier ———Y Y Y Y
Common thresher shark Alopias vulpinus ———————Y
Atlantic angel shark Squatina dumerii ———————Y
Dusky shark c Carcharhinus obscurus ————Y Y Y
Sand tiger shark Carcharias taurus ———Y Y Y Y
Smooth dogfish Mustelus canis ———————Y
Atlantic sharpnose shark Rhizoprionodon terraenovae ———Y Y Y Y
Blacknose shark Carcharhinus acronotus —————Y Y
a EFH for juveniles to Cape Hatteras; mostly north of 38 ° according to MAFMC Amendment 11 * indicates species managed by MAFMC
b EFH for adults includes Hatteras Inlet ** indicates EFH/HAPC within project area
c EFH Amendment 10 appears to not include Cape Hatteras when zoomed
Greater Atlantic region
Mid-Atlantic species
South Atlantic region (SAFMC)
Life stage category
Managed species and geographic region
Smoothhound shark complex (NMFS)
Small coastal sharks (NMFS)
Highly migratory species (NMFS)
Billfish (NMFS)
Large coastal sharks (NMFS)
Pelagic sharks (NMFS)
Prohibited sharks (NMFS)

https://www.habitat.noaa.gov/application/efhmapper/index.html

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TABLE 5.3. EFH type and EFH/ HAPC within the project vicinity or project footprint for which potential impacts may occur.
Includes ASFMC-managed species and SAFMC EFH or EFH/HAPC (as shown in Table 5.1) and the protected resource designated
to that habitat under a fishery management plan (FMP) developed for each protected resource. Updated from SAFMC (2020)
http://safmc.net/download/SAFMCEFHUsersGuideFinalNov20.pdf
(* indicates ASMFC habitat, ASMFC EFH-HAPC, or SAFMC EFH; ** indicates SAFMC EFH-HAPC).

HABITAT TYPE FMP ASMFC
Unconsolidated bottom* Red drum, snapper grouper,
spiny lobster1
Red drum, horseshoe crab,
scup, spiny dogfish, summer
flounder

Offshore marine habitats used for
spawning and growth to maturity* Shrimp, snapper grouper
Atlantic menhaden, Atlantic
striped bass, Atlantic
sturgeon, bluefish, alewife,
American shad, blueback
herring, hickory shad,
Spanish mackerel, spiny
dogfish, spot, spotted
seatrout, weakfish, Atlantic
coastal sharks
Ocean high salinity surf zones* Red drum, coastal migratory
pelagics
Red drum, Atlantic striped
bass, bluefish, spotted
seatrout, Atlantic coastal
sharks

Spawning area in the water column
above the adult habitat and the
additional pelagic environment,
including Sargassum; Sargasso Sea*

Snapper grouper, coastal
migratory pelagics American eel

Barrier island ocean side waters from
the surf to shelf break zone but
shoreward of the Gulf Stream*

Coastal migratory pelagics

Horseshoe crab

Shallow subtidal bottom*

Spiny lobster1 Horseshoe crab, scup

Pelagic Sargassum habitat**
(windrows in nearshore project
vicinity)**

For dolphin under coastal
migratory pelagics American eel, cobia
Sandy shoals of Cape Hatteras from
shore to the ends, but shoreward of
the Gulf Stream**

Coastal migratory pelagics
Red drum, horseshoe crab,
scup, bluefish, summer
flounder
1 not usually found north of southern North Carolina coast

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TABLE 5.4. Management history of designated EFH for highly migratory species (HMS). (Table 3.1 from NOAA 2017; updated).

FMP or Amendment EFH and Species
1999 FMP for Atlantic tuna,
swordfish, and sharks
EFH first identified and described for Atlantic tunas,
swordfish and sharks; HAPCs designated for sandbar sharks
1999 Amendment 1 to the 1988
Billfish FMP EFH first identified and described for Atlantic billfishes
2003 Amendment 1 to the FMP for
Atlantic tunas, swordfish and sharks
EFH updated for five shark species (blacktip, sandbar,
finetooth, dusky, and nurse sharks)
2006 Consolidated Atlantic HMS FMP
Comprehensive review of EFH for all HMS. EFH for all Atlantic
HMS consolidated into one FMP; no changes to EFH
descriptions or boundaries
2009 Amendment 1 to the 2006
Consolidated Atlantic HMS FMP
EFH updated for all federally managed Atlantic HMS. HAPC
for bluefin tuna spawning area designated in Gulf of Mexico
2010 Amendment 3 to the 2006
Consolidated Atlantic HMS FMP
EFH first defined for smoothhound sharks (smooth dogfish,
Florida smoothhound, and Gulf smoothhound)
2010 White Marlin/Roundscale
Spearfish Interpretive Rule and
Final Action
EFH first defined for roundscale spearfish (same as white
marlin EFH designation in Amendment 1 to 2006
Consolidated Atlantic HMS FMP)
2015 Atlantic HMS EFH
5-Year Review
Comprehensive review of EFH for all HMS. Determined that
changes to some EFH descriptions and boundaries were
warranted.
2016 Draft Amendment 10 to the
2006 Consolidated Atlantic HMS FMP
Presents alternatives that would update EFH for all federally
managed Atlantic HMS. Existing HAPCs for sandbar shark
and bluefin tuna would be adjusted, and new HAPCs for
sand tiger shark and lemon shark would be created to reflect
recommendations in the 5-year review
2017 Final Amendment 10 to the
2006 Consolidated Atlantic HMS FMP

Public comment period ended 22 December 2016. Final
amendment approved 30 August 2017 and published in
Federal Register on 7 September 2017

2019 Final Amendment 11 to the
2006 Consolidated Atlantic HMS FMP
Public comment period ended 1 October 2018 and Final
became effective 3 March 2019. Included management
measures to address overfishing and rebuild stock of North
Atlantic shortfin mako shark
2020 Draft Amendment 12 to the
2006 Consolidated Atlantic HMS FMP
Announced 23 June 2020 integrates provisions of recently
revised National Standard guidelines, a standardized
bycatch reporting methodology rulemaking, and NOAA
Fisheries policy directives. Public comment closed 26
October 2020.

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TABLE 5.5. EFH types and geographically defined HAPCs within proposed project vicinity or footprint and potential impacts by
activity (Y = yes; N = no; W =within acceptable limits). Refer to Section 5.0 and 6.0 for details.

PROXIMITY IMPACT ACTIVITY
Essential Fish Habitat Project
vicinity
Project
footprint
Dredge
operation Sand placement
Estuarine
Emergent wetlands Y N N N
Estuarine scrub/shrub mangroves N N N N
Submerged aquatic vegetation (SAV) Y N N N
Oyster reefs and shell banks Y N N N
Intertidal flats Y N N N
Aquatic beds N N N N
Estuarine water column Y N N N
Seagrass Y N N N
Creeks N N N N
Mud bottom N N N N
Marine
Emergent wetlands Y N N N
Unconsolidated/shallow subtidal
bottom Y Y Y Y
Live/hard bottoms N N N N
Coral and coral reefs N N N N
Artificial/man-made reefs N N N N
Sargassum Y Y W N
Water column & high salinity surf zones1 Y Y W W
Geographically Defined HAPC
Area-wide
Council-designated artificial reef Special
Management Zones N N N N
Hermatypic (reef-forming) coral habitat
and reefs N N N N
Hard bottoms N N N N
Hoyt Hills N N N N
Sargassum habitat Y Y W N
State-designated areas of importance
for managed species (PNAs) N N N N
Submerged aquatic vegetation (SAV) Y N N N
North Carolina
Big Rock N N N N
Bogue Sound N N N N

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TABLE 5.5. (concluded)

PROXIMITY IMPACT ACTIVITY
Geographically Defined HAPC Project
vicinity
Project
impact area
Dredge
operation Sand placement
Pamlico Sound at
Hatteras/Ocracoke islands N N N N
Cape Fear sandy shoals N N N N
Cape Hatteras sandy shoals Y Y W N
Cape Lookout sandy shoals N N N N
New River N N N N
The Ten Fathom Ledge N N N N
The Point N N N N

1 effect is likely to be negligible (e.g., project turbidity in surf zone water column would be very temporary
and similar conditions commonly occur naturally and often for longer duration)

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FIGURE 5.1. Location of hard bottom, possible hard bottom, shipwrecks, and artificial reefs in state and federal waters off
North Carolina- northern coast (from NCDEQ 2016c, Map 7.1.a). Blue arrow points to Avon Village

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Areas shown in Fig. 5.2 include EFH-HAPC as follows: The Point (largest green unidentified
rectangle) for Coastal Migratory Pelagics, Coral, Coral Reef, Live/Hard Bottom, Tilefish,
Snapper/Grouper, and Dolphin/Wahoo is located approximately 25 miles offshore from
Buxton/Cape Point/Cape Hatteras and the proposed project area; the sand colored narrow polygon
south and north of The Point for tilefish; coastal inlets (blue circles) for Shrimp and
Snapper/Grouper, and; the grey, blue, or green colored polygons along the shores of Pamlico Sound
for Primary and Secondary and Permanent Secondary Nursery Areas for Shrimp and/or
Snapper/Grouper. Note: the marsh on the sound side of Hatteras Island in vicinity the proposed
project area contains no EFH-HAPC designated Nursery Areas.

Cores from the borrow areas were logged and analyzed for grain size, shell content, and mud
content using sample splits at distinct changes in lithology, and the results showed that the
sediment quality in the designated borrow areas met the North Carolina Coastal Resources
Commission (NCCRC) criteria (15A NCAC 07H.0312 – Technical Standards for Beach Fill Projects).
The similarity of the sand-size classes and shell content in sediment analyses for the recipient
beach and the borrow areas indicate for the proposed nourishment project that th e sand will look
and perform similar to native sand after placement on the beach.

The majority of the cores represent the upper 10 feet of substrate, therefore, Dare County proposes
a maximum allowed excavation depth of 10 ft for Borrow Area 1 and 6 ft for Borrow Area 2 below
the existing grade. If the proposed excavation depth is approved, the borrow areas contain
approximately 3.4 million cy of beach-quality sand. All hardbottom features or cultural resources
identified within the project area will be avoided and appropriate buffers will be incorporated.

The potential pipeline corridors for a cutterhead dredge operation or a hopper dredge operation
have not been determined at this time. It is anticipated that the project will be constructed via
ocean-certified hopper dredge so as to maintain flexibility and safety during temporary
demobilization to a safe harbor in rough sea conditions. Offshore hopper dredging operations do
not require a continuous pipeline from the borrow areas to the beach, instead a relatively short
segment of submerged pipe is used that extends from safe water depths to the shoreline. The
anticipated submerged pipeline will be ~2,000 ft placed along the bottom more or less normal to
the shoreline azimuth. Multiple pumpout points are anticipated for the project (likely a maximum
of three corridors). Additional surveys will be conducted once the borrow areas and parameters for
corridor spacing are confirmed with prospective dredging companies (requirements vary with the
size of dredges assigned to the project). All information associated with additional surveys, data
analysis, mapping of corridors and proposed buffers will be coordinated with resource agencies
prior to construction so as to avoid or minimize resource impacts. Final pipeline corridors also
cannot be determined until the time of construction because of the need to avoid designated
resource closure areas.

The nearshore zone of impact of the beach fill will be a function of the normal annual to decadal
depth of active profile change (i.e., Depth of Closure – DOC) along the foreshore, which for the
northern Outer Banks area is in the approximate range -19 ft NAVD to -30 ft NAVD (Birkemeier 1985;
USACE 2010). A recent analysis determined -24 ft NAVD for Avon (CSE 2020). During construction,
all nourishment along Nags Head was placed landward of the −12 ft contour. This was confirmed
by pre- and post-nourishment construction surveys and post-storm surveys after Hurricane Irene
after 85 percent of the nourishment was in place (CSE 2013). Subsequently, over a three year
period, sand from the nourishment project shifted seaward to the approximate −19 ft NAVD contour

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with additional evidence of minor profile change between the −19 and −30 ft NAVD depth contours.
Thus, the zone of impact is initially smaller than the subsequent area receiving inputs of sand as
equilibration occurs. The post construction adjustment of the profile tends to be rapid (order of
weeks to months along the Outer Banks) in the surf zone, but relatively slow and event driven in
deeper water.

FIGURE 5.2. A screen shot of SAFMC designated EFH-HAPC near proposed project (SAFMC EFH Viewer webpage accessed 15 October 2020). See text for description of highlighted areas. https://www.habitat.noaa.gov/protection/efh/efhmapper/

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5.1 Potential EFH or EFH-HAPC within Project Impact Area and Fish Species Which Utilize Them

This section of the assessment document expands upon the currently designated EFH or EFH-HAPC
with the potential to occur within the project vicinity (within 2 miles of project area footprint) or
project area (actual project footprint) listed in Table 5.5. Fish utilization is described in more detail
for only those EFH or EFH-HAPC found within both the project vicinity and the project area.

5.1.1 Estuarine Emergent Wetlands - the Cowardin et al. (1979) definition is accepted by NOAA for
the description of this EFH and includes deepwater tidal habitats and adjacent tidal wetlands that
are semi-enclosed by land but have some open, or partly obstructed, or sporadic connection to
marine waters which mix with freshwater runoff from the land. The seaward limi t is an imaginary
line drawn across the mouth of a river, bay, or sound. This EFH provides important nursery habitat
for penaeid shrimp and snapper grouper and is also highly productive for many other non-managed
species. The nearest estuarine emergent wetlands lie on the west side of Hatteras Island which do
fall within the project vicinity but will not be affected by the beach and dune restoration initial
project as there is no nearby inlet to transport waters or sediment from the project into the EFH.
Also, no project-related equipment will travel or be parked in or near this EFH during the initial
restoration. Therefore, this EFH is not evaluated further in this document.

5.1.2 Submerged Aquatic Vegetation (SAV) and Seagrass – these shallow estuarine or marine
EFHs perform many critical ecological functions and are highly productive for multiple protected
and managed species. These species, along with other recreationally important shellfish,
invertebrates, and forage species for the managed species, utilize the complex SAV habitat for
spawning, nurseries, feeding, attachment, and refugia. Both the patches of SAV itself (stems, roots,
rhizomes, leaves and propagules) and the area between patches are considered SAV habitat. High
salinity SAV habitat in NC waters is generally dominated by three species of seagrass, shoal grass
(Halodule wrightii), widgeon grass (Ruppia maritima), and saltwater eelgrass (Zostera marina).
Siltation, damage from boat props and wakes, and other changes in water quality or substrate
affect ability of SAV to thrive and extend coverage. Over 40,000 fish and 1,000 times as many small
invertebrates are supported by a single acre of seagrass (https://ocean.si.edu/ocean-life/plants-
algae/seagrass-and-seagrass-beds). While recognized around the world for its critical and highly
productive ecological functions, there has been a global decline in SAV and seagrasses of about 29
percent in the last century with a current loss estimate of 1.5 percent/year (two football fields each
hour). Estimated to encompass between 134,000 to 200,000 acres, North Carolina has the third
largest expanse of SAV in the US along with Maine and Texas. While SAV habitat is extensive in some
areas and patchy in other areas of NC waters, the nearest SAV is located in Pamlico Sound, directly
across Highway NC 12 to the west, in the back barrier environment. Data from the most recent
information on SAV in North Carolina waters were used to show 6,317 acres of both patchy and
continuous SAV beds within the project vicinity (Fig 5.3). Shown in Kenworthy et al. (2012) as
covered densely with high salinity SAV, these acres of SAV lie within the project vicinity but outside
the project area; the nearest inlet which could transport any waters or sediment from the initial
sand placement on the beach and dunes from the offshore borrow areas is ~16 miles southwest.
Therefore, this EFH is not evaluated further in this document.

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FIGURE 5.3. Submerged aquatic vegetation within project vicinity.

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5.1.3 Oyster Reef and Shell Banks - Oyster reefs and shell banks are intertidal or subtidal estuarine
habitats composed of living shellfish or artifact shell material. Several species of specialized fish
and invertebrates are associated with oyster reefs as these habitats
provide food and cover. Managed species associated with this EFH include black sea bass, grey
snapper, weakfish, and bluefish. Living oyster populations are limited by, among other things,
siltation, salinity, and substrate. Throughout their entire Atlantic range, oyster reefs have declined
substantially in the last century because of natural and anthropogenic stressors. Efforts currently
are underway to regenerate oyster reefs in many states, including NC which has numerous living
shoreline projects completed and others under development; living shoreline projects use oyster
shell reefs to aid in estuarine shoreline stabilization and water quality improvements (6,200 linear
feet of living shoreline in North Carolina have been restored in the past 20 years through a
partnership between NOAA fisheries and the NC Coastal Federation). Habitat for and likely patches
of oyster reef or shell bank are found within the project vicinity in the back barrier environments of
Pamlico Sound but none are found within the project area. As mentioned for SAV, the nearest inlet
to transport any waters or sediment from the project area is ~16 miles southwest of the initial sand
placement activity. Therefore, this EFH is not evaluated further in this document.

5.1.4 Estuarine Intertidal Flats – this EFH is extensive throughout Pamlico Sound and is an
important component of primary and secondary nursery areas and is considered a soft bottom
habitat per NCDEQ 2016a,b). Described by SAFMC as dynamic areas that change and respond to
shifts in sediment supply based on patterns of erosion and deposition, this EFH provides habitat for
numerous benthic organisms which comprise important dietary components of many managed
species and recreationally important fish species such as gag grouper, grey snapper, American eel,
red drum, shrimp, summer flounder, and black sea bass. As described for SAV and oyster reef/shell
banks, the nearest estuarine intertidal flats lie in Pamlico Sound to the west of NC 12, in the project
vicinity but not in the project area. Therefore, this EFH is not evaluated further in this
document.

5.1.5 Sargassum and Sargassum Pelagic Habitat – Sargassum filipendula is a benthic brown
macroalgae found along the Atlantic coast of the Americas in shallow subtidal zones attached to
rocks or shells, but is also found in deeper waters of 80 to 100 ft. In North Carolina, this alga occurs
predominantly south of Cape Hatteras often growing on jetties near stabilized inlets. As it has larger
floats than other species of Sargassum and weaker holdfasts, rough weather will often dislocate
the holdfasts and it is often carried out to the open ocean where it joins other species of seaweed
and Sargassum in the Sargasso Sea. Positively buoyant, the larger floats of S. filipendula keep it on
top of the large floating mats of seaweed common to the Sargasso Sea. Of the 150 species
worldwide, two other free-floating species of Sargassum are found in the Atlantic, S nutans and S
fluitans with S. nutans the most common. Sargassum can occur in large floating mats in the waters
of the continental shelf, in the Sargasso Sea, and in the Gulf Stream and can appear as
concentrations of small patches (Figure 5.4), large mats, or often miles-long weed lines, or
windrows, along current convergence boundaries in the open or coastal ocean (Deaton et al. 2010,
NCDEQ 2016a,b). It circulates primarily between 20° and 40° N latitudes and 30° W longitude and
the western edge of the Florida Current/Gulf Stream. Masses of Sargassum provide a mobile
structural home for over 100 species of fish (mostly larval and juveniles; left photo Figure 5.4), fungi,
and micro- and macro-epiphytes, at least 145 species of invertebrates, four species of sea turtles,
and numerous marine birds. Roughly 2M square miles in area, the Sargasso Sea is bordered by a
ring of four currents; on the north by the North Atlantic Current, on the east by the Canary Current,
on the south by the North Atlantic Equatorial Current, and on the west by the Gulf Stream. These

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currents rotate a large eddy in a clockwise circulation (the North Atlantic Central Gyre) and also
trap floating debris and trash/plastics such that the area is known as the North Atlantic Garbage
Patch. The Sargasso Sea receives little wind or rain. The rotation keeps the masses of Sargassum
and other seaweed in the Sargasso Sea from dispersing into other parts of the ocean; although
some smaller rafts or windrows do separate from the larger masses under certain wind and current
conditions and drift in the open ocean (middle photo, Figure 5.4) or can be driven all the way to
shore (right photo, Figure 5.4).

Legally, SAFMC considers the Sargassum vegetation as both EFH and as a “fish” under the MSFCMA.
Designated EFH or EFH-HAPC for Snapper/Grouper, Highly Migratory, and Coastal Migratory Pelagic
fisheries, it is also the area to which all American and European eels are thought to congregate for
spawning. It is a major source of biological productivity in nutrient-poor regions of the ocean tightly
coupled to schools of associated fish. However, unregulated commercial harvest of Sargassum for
traditional medicines, fertilizer, livestock feed, and the cosmetics industry has prompted concerns
over the potential loss of this important resource. It is illegal to harvest south of the NC/SC
boundary or within 100 miles of shore and any harvest is limited from November to June to protect
sea turtles. Under certain wind conditions, relatively small masses of Sargassum may wash ashore
from the Gulf Stream or outer continental shelf waters and it can also be found occasionally in
nearshore waters. Since 2011, beaches of the Caribbean have experienced massive influx of two
species of Sargassum along with the western equatorial coast of Africa. The source of this new and
unpleasant (for tourism) and fatal (smothered sea turtle nests, fish kills) Caribbean phenomena at
first was thought to be the Sargasso Sea or the Gulf of Mexico but satellite images revealed it to
originate from the coast of Brazil transported by equatorial currents. This recent spate of
Sargassum blooms is suspected to be driven by increased nutrients from the Amazon River (and
potentially the Congo River) in addition to potential changes in water temperature due to climate
change, iron rich African dust plumes, or changes in the complex dynamics of the North Equatorial
Recirculation Region (NERR) (Oxenford, 2015; Louime et al. 2017; University South Florida 2019;
Langin 2019; McBride 2019).

5.1.6 Water Column – the water column is the medium which connects all aquatic habitats,
provides a basic ecological role for all organisms within it, and performs an essential corridor
function for species which depend on more than one habitat for various life stages (Deaton et al.
2010; NCDEQ 2016a,b). Either or both the estuarine and marine water column are EFH for all
managed species as shown in Table 5.2. Life stages of many of the species are found in the nearby
estuarine waters of the North Carolina back-barrier sounds (Roanoke, Pamlico, and Croatan
sounds) and/or nearest inlets (Oregon Inlet is ~30 miles to the north and Hatteras Inlet is ~16 miles
to the southwest). Some other managed species can be found in the nearshore marine waters of
the proposed borrow areas or in the surf zone in the vicinity of proposed sand placement. A project
conducted from March 2015 to October 2019 by NOAA’s National Center for Coastal Ocean Science
(NCCOS) developed a calendar of environmental windows which shows the monthly distribution of
sensitive early life stages for important fishery species in the Carolinas and which aquatic
regime/type these stages are found (Figure 5.5). The purpose of the project was to provide a guide
for coastal resource managers to reduce and minimize development-related impacts to fisheries.

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FIGURE 5.4. Floating mat of Sargassum with associated small fish (courtesy of NOAA Ocean Explorer Gallery),
weedline/windrow of Sargassum (SAFMC website) and drifts on Caribbean island of Tobago in 2015 (Credit:
rjsinenomine (CC BY 2.0)] and monthly Sargassum distribution derived from MERIS satellite imagery from 2002-
2008 (as shown in Oxenford, Franks, and Johnson 2015).

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FIGURE 5.5. Distribution of sensitive life stages of important fishery species in the Carolinas across the months of
the year by aquatic type/location. (https://coastalscience.noaa.gov/project/fisheries-assessment-to-inform-time-
of-year-restrictions-for-nc-and-sc/)

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5.1.6.1 Estuarine water column – EFH for multiple managed species under various FMPs: coastal
demersals (red drum, bluefish, summer flounder), invertebrates (shrimp species), coastal pelagics
(e.g., cobia, both mackerels), some sharks, and the snapper grouper complex (e.g., black and rock
sea bass, Lane and grey snapper, sheepshead) and HAPC for shrimp, snapper/grouper, and red
drum. While the nearest waters of Pamlico Sound are within 1,000 ft or less of the proposed sand
placement area, the dry beach, the dunes (where they exist), NC Highway 12, and vegetated and
unvegetated habitats separate the project area from the estuarine water column. The distance to
the nearest inlet which could connect the project area marine water column to the estuarine water
column is ~16 miles to the southwest. Therefore, this EFH is not evaluated further in this
document.

5.1.6.2 Marine water column – this broad EFH includes ocean high salinity surf zones EFH for red
drum and coastal migratory pelagics, barrier island ocean-side waters from surf zone to shelf break
and from Gulf Stream shoreward EFH for coastal migratory pelagics, and spawning area above
adult habitat and additional pelagic environment EFH for snapper grouper and shrimp under
various FMPs. Additionally, the marine water column is utilized by various life stages of ASMFC
species including Atlantic menhaden, shad, spotted seatrout, spiny dogfish, and Atlantic coastal
sharks among others. The coastal and nearshore Atlantic Ocean waters of North Carolina occupy
a unique location in that the colder southerly Labrador Current (a portion of the North Atlantic gyre)
intersects with the warmer northerly Gulf Stream in the vicinity of Cape Hatteras, which also is a
biogeographic boundary and is the closest point of land to the Gulf Stream along the mid-Atlantic
coast (see Section 5.1.5.9 Cape Hatteras shoals for further discussion). This collision of currents
generally decreases the marine water column temperatures north of Cape Hatteras and increases
temperatures south of Cape Hatteras. The collision generates offshore frontal mixing zones which,
combined with the varied winds and shifting bottom topography characteristic of Cape Hatteras
shoals, causes nutrient-rich upwelling. Upwelling in the area can also be driven by wind events and
local topography. Upwelling supports a large diversity of larval to adult stages of managed fish,
including Highly Migratory Species and results in the HAPC called The Point (a rectangular area
along the continental shelf break east of Cape Hatteras shown in Fig 5.2). These marine waters
concentrate pelagic fauna relatively close to shore from the temperate biogeographic region to the
north and tropical to sub-tropical biogeographic region to the south. The complex topography of
the Carolina Capes region extends to the continental shelf break and is effective at capture of Gulf
Stream eddies (FEP II live/hardbottom update March 2018 (https://safmc.net/uncategorized/fepii-
live-hardbottom-habitat_march-2018/). Figure 5.6 is a cartoon depiction of this unique collision of
currents.

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
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FIGURE 5.6. Depiction of Cape Hatteras marine water column dynamics.
(from https://www.coastalstudiesinstitute.org/research/coastal-engineering/research-project-processes-driving-
exchange-cape-hatteras)

Laney et al. (2007) indicated that juvenile Atlantic sturgeon (Acipenser oxyrinchus) were consistently
captured in January - February bottom trawls from 1988 to 2006 in the shallow nearshore waters of
North Carolina north of Cape Hatteras, including captures nearer to the Buxton project vicinity than
to Avon. However, most of the captures were concentrated north of Oregon Inlet (Fig 3 of Laney et
al. 2007, pg 175). An index of the estimated Atlantic coast population abundance for Atlantic
sturgeon was developed from the Northeast Fisheries Observer Program (NEFOP) during 2006 to
2011 (Kocik et al. 2013). The Kocik et al. report (2013) includes a map of the capture locations along
the North Carolina coast (Fig 1, pg 26) which indicates that Atlantic sturgeon were not captured
within the Avon project area itself but were captured both to the north and south; an absence
potentially linked to the distances to an inlet.

There are 23 species or species groups managed interjurisdictionally under ASMFC, SAFMC, and/or
MAFMC and the NC Marine Fisheries Council (NCDEQ 2015, Table 1). As of 28 August 2019, North
Carolina has 13 FMPs two of which (red drum and summer flounder) also have ASMFC or MAFMC
FMPs and one of which has a SAFMC FMP (shrimp). From 1978 -1993, North Carolina commercial
fisheries landings statistics were collected on a voluntary basis through the National Marine
Fisheries Service/North Carolina Cooperative Statistics Program. The growing need for more
detailed and timely harvest data led the NC General Assembly to mandate trip-level reporting of
commercial fisheries landings for all state-licensed fish dealers in 1994. Since that time, the N.C.
Division of Marine Fisheries Trip Ticket Program has grown into one of the leading fisheries data
collection programs in the country. In fact, many other states have modeled their trip ticket systems
after the North Carolina program.

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2403M–Task 4–Appendix F] 42 Avon Village, Dare County, North Carolina

The NCDMF provided summary data for commercial landings in the ocean up to 3 miles off the
beach from north of Cape Hatteras to the Virginia border from 2000-2019 (NCDMF, Amanda Tong,
Marine Biologist II, License and Statistics Section, pers comm.17 October 2019 and 9 February
2021). Values for taxa richness, total weight, percent of catch, and numbers of managed species
derived from the summary data are higher or lower than that shown below as some data are
confidential and not shared with the public and some species are lumped into a group that may or
may not include only the managed species. For example, among highly migratory species in the
summary data, four tuna are represented (three of which are confidential) and 18 shark species are
represented (seven are confidential). Figure 5.7 shows the dominant species by tonnage and Figure
5.8 shows the data for sharks not shown in Figure 5.7. Bangley et al. (2018) analyzed NCDMF gill net
and longline survey data from 2007-2014 which showed that six species of shark were most
common in Pamlico Sound: spiny and smooth dogfish, bull shark, blacktip shark, sandbar shark,
and Atlantic sharpnose shark. The analysis showed that sharks were most associated in habitats
with high salinity, warmer temperatures, and proximity to inlets with the exception of bull shark
which was found at greater distances from inlets and spiny dogfish which was associated with lower
temperatures and SAV beds. Bull shark has no designated EFH in NC waters (Table 5.2). The bullet
list below provides additional information from the NCDMF summary commercial data:

 Total taxa richness = 124
 Total sample = 27,644 tons
 Managed species comprised 58.1% of total as follows:
Coastal demersals = 13.1%
Invertebrates (shrimp & squid) = 10.1%
Coastal pelagics = 3.7%
Highly migratory = 1.67%
Sharks = 1.66%
Snapper/grouper = 0.2%
 Top individual managed fish species taken was Atlantic croaker
Micropogonias undulatus) = 35.8%
 Other top individual managed fish species taken were less than
15% of total as follows:
Spiny dogfish (Squalus acanthias) = 13.4%
Bluefish (Pomatomus saltatrix) = 8.1%
Shrimp (three species) = 10.0%
Flounders (Paralichthid) = 5.0%
Striped bass (Morone saxatilis) = 4.9%
Smooth dogfish (Mustelus canis) = 3.4%
Menhaden (bait) (Brevoortia tyrannus) = 3.4%
Weakfish (Cynoscion regalis) = 2.9%

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
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FIGURE 5.7. Dominant fish species caught in commercial landings from 2000-2019 per NCDMF.
Data limited to 0 to 3 miles offshore from Cape Hatteras to Virginia border, Shrimp (all) includes
pink, white, and brown shrimp, and Flounders includes all Paralicthids.

FIGURE 5.8. Other sharks caught in commercial landings from 2000-2019 per NCDMF. Data
limited to 0 to 3 miles offshore from Cape Hatteras to Virginia border. Shortfin mako shark
landings were slightly more than 1 ton over this period; data for seven other shark species were
confidential and not made public.

0
2,000
4,000
6,000
8,000
10,000
12,000
NCDMF Trip Ticket Summary Tons
Buxton to Virginia border
(2000-2019)
0
50
100
150
200
NCDMF Trip Ticket Summary Tons
Buxton to Virginia border
(Sharks 2000 -2019)

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
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Despite, or possibly even because of, their frequently turbulent waves, ocean high salinity surf
zones provide habitat for a diversity of fishes and are prime sites for recreational anglers and
commercial net fisheries. This EFH also faces other escalating pressures from coastal urbanization
and shoreline stabilization. Managed species typically found in the surf zone of Avon can include
bluefish, cobia, king and Spanish mackerel, sheepshead, summer flounder, brown/pink/white
shrimp, bluefish, and several shark species.

Olds et al. (2017) reviewed the global literature (152 studies gathered from Elsevier Scopus and ISI
Web of Knowledge databases) on the ecology of surf zone fish to inform fisheries management and
coastal conservation planning. While the ecological and economic importance of surf-zone fishes
is widely recognized, Olds et al. (2017) conclude that few studies tested for impacts on fishing from
urbanization or whether the impacts were severe in surf zones. The literature referenced in Olds et
al. (2017) showed surf zones support diverse fish assemblages characterized by high numerical
dominance (10 species typically comprise 95 percent of catches), but also showed the composition
of assemblages as highly variable, changing with fluctuations in water temperature, wave climate,
and the biomass of drifting algae or seagrass. The literature reviewed showed mostly positive
effects from water temperature, macrophytes, and wind speed and mostly negative effects from
wave climate, salinity, and turbidity on surf zone fish assemblages (see Figure 5 in Olds et al. 2017).
The studies cited in Olds et al. (2017) show that fish use surf zones as feeding habitats and transit
routes, but these areas may not be widely used as spawning sites, juvenile nurseries, or refugia and
indicate that the hypothesized habitat functions are rarely backed by empirical data (Able et al.
2013, Tobin et al. 2014, Vargas-Fonseca et al. 2016 are cited). Somewhat surprisingly, the
presumption that gutter habitats in surf zones serve as effective refugia from predators for juvenile
fish is also challenged by the Olds et al. (2017) literature review (specifically Nakane et al. 2009,
Tobin et al. 2014).

Furthermore, Olds et al. (2017) conclude that while intense fishing pressure leads to significant
reductions in fish abundance, biomass, and diversity, no published data exist that can be used to
determine what level of surf zone fishing effort is sustainable, which species are particularly at risk
from harvesting in surf zones, or whether different modes of fishing exert distinct pressures. They
also conclude that few studies have examined how surf fish assemblages are modified by
environmental conditions (e.g. wave climate, water quality and drifting macrophytes).
Morphological features of beaches are governed by sediment supply, tides, and wave exposure
which individually or in combination alter the availability of both food (e.g. invertebrate prey or
macrophytes) and habitat (e.g. gutters, runnels, bars) for surf fishes, but to what extent they
influence the composition of surf fish assemblages remains unclear (Olds et al. 2017). Regardless
of the need for more research to close gaps in understanding surf zone fish ecology as suggested
by this literature review, this EFH is widely recognized to provide connectivity for fish to other
habitats, support food webs, and perform important ecosystem services (Olds et al. 2017).

Summary data for recreational landings (beach and up to 3 miles offshore) at Avon access sites
from 2004-2019 was provided by NCDMF (Personal communication, Andrew Cathey, Biologist
Supervisor, License and Statistics Section 17 February 2021). Summary data includes interception
of anglers and catch observation at six different fishing access locations in the Avon area (beach
access points and Avon pier). In close proximity to the proposed project footprint, the Avon pier
had the largest number of intercepts over the 16 years (3,011) while Ramp 30 beach access had the

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2403M–Task 4–Appendix F] 45 Avon Village, Dare County, North Carolina

lowest (565); the other four intercepts occurred at Ramps 27, 32 (since 2018), 34, and 38 in the
Seashore. Unlike the commercial landings data, these data are not separated by year and
summarize total observed catch by species for the entire period. Figure 5.9 shows the dominant
species by total catch (total includes individuals released) and the list below provides additional
information from the summary recreational NCDMF data:

 Total taxa richness = 53 (identified to species)
 Total sample = 15,437 individuals
 Cooperatively or federally managed species comprised 43.9% of total as follows:
Coastal demersals = 29.3%
Sharks = 5.5%
Highly migratory = 5.5%
Coastal migratory pelagics = 0.8%
 Top individual managed fish species taken was bluefish = 12.5%
 Other top species taken were as follows:
Spot (Leiostomus xanthurus) = 19.9%
Atlantic croaker (Micropogonias undulatus) =15.9%
Unidentified kingfish (Menticirrhus spp.) = 13.3%
Florida pompano (Trachinotus carolinus) = 4.1 %
Southern kingfish (Menticirrhus americanus) = 3.7%
Unidentified skates/rays = 3.4%
Unidentified sharks = 3.2%
Lefteye flounder (Bothidae) = 2.3%
Spotted seatrout (Cynoscion nebulosus) = 1.8%
Red drum (Sciaenops ocellatus) = 1.7%
Black drum (Pogonias cromis) = 1.1%

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2403M–Task 4–Appendix F] 46 Avon Village, Dare County, North Carolina

FIGURE 5.9. Dominant fish species observed during recreational angler intercepts at six locations
in Avon vicinity from 2004-2019 per NCDMF. Note: sixth location only added in 2018.

5.1.7 Hard Bottom – while more than 90 percent of the hard bottom EFH of North Carolina occurs
south of Cape Lookout, numerous occurrences of hard bottom or potential hard bottom exist north
of Cape Hatteras. However, north of Cape Lookout the nearshore hard bottom EFH including
shipwrecks often have low relief which makes them ephemeral (a storm may bury or uncover the
habitat). The EFH can include both natural (rock outcrops) and unnatural components
(shipwrecks). Pleistocene algal communities account for the natural hard bottom features (slight
ridges, ledges and small terraces) found on the continental margin hard bottoms of both North and
South Carolina; hard bottom can also be other natural outcroppings of limestone or unnatural
man-made debris/structure.

All hard bottom vertical structure attracts and supports a diverse assemblage of invertebrate
colonizers (e.g., sponges, seaweed) which in turn attract and support a diverse assemblage of
vertebrate organisms. All nearshore hardbottom is designated EFH for snapper, grouper, gag
grouper, mackerel, and spadefish. The NCDMF website states that hard bottom provides nursery
habitat for grouper, spadefish, and black sea bass while king mackerel, gag grouper, and grouper
forage above or on hard bottom itself (http://portal.ncdenr.org/web/mf/habitat/hard-bottom).
The NCDMF website also states this EFH provides spawning area for black sea bass, grouper, and
damselfish and refuge for gag grouper and black sea bass.

5.1.8 Artificial/man-made reefs – used for centuries to enhance fishery resources prior to their
designation as EFH, these areas serve many of the same functions as natural reefs whether they
are a natural shipwreck, a deliberately sunken ship, or other man -made structure (e.g., jetty,
groin, reef ball). As a fishery management tool, properly constructed and strategically sited
artificial reefs help offset the loss or damage of natural reef habitat to bottom -fishing gear and
pollution and rebuild reef -associated fish stocks (NOAA 2007). A rtificial reefs provide habitat
structure where species may reproduce, spawn, hide, and forage; therefore, these structures
0
500
1,000
1,500
2,000
2,500
3,000
3,500
SPOT ATLANTIC
CROAKER
KINGFISH
GENUS
BLUEFISH FLORIDA
POMPANO
SOUTHERN
KINGFISH
UNID
SHARKS
Total Numbers of Dominant Fish Avon Vicinity (0 -3 miles)
NCDMF Angler Intercepts
2004-2019

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[2403M–Task 4–Appendix F] 47 Avon Village, Dare County, North Carolina

increase the carrying capacity of what once was soft bottom habitat (NCDEQ 2016a,b). In North
Carolina, the NCDMF Artificial Reef Pr ogram manages 41 ocean reefs, 8 estuarine reefs, and eight
estuarine oyster sanctuary fishing reefs some of which are shown by triangles on Figure 5.1. All
of the artificial reef sites are outside of the project vicinity. Dredging in the proposed offshore
borrow areas and placement of material associated with proposed project would not be expected
to adversely affect artificial reef sites managed by the Artificial Reef Program. Therefore, this
EFH is not evaluated further in this document.

5.1.9 Primary and Secondary Nursery Areas (PNAs/SNAs) – these EFH/HAPC areas are
designated as areas of importance for managed fish by the North Carolina Marine Fisheries
Commission and are defined by North Carolina as tidal salt waters that provide essential habitat
for the early development of commercially important fish and shellfish (15 NC Administrative Code
03R .0103-0105). These habitats are also of particular importance to multiple species important to
North Carolina fisheries as identified in NC Coastal Habitat Protection Plan (CHPP) (Deaton et al.
2010; NCDEQ 2016a,b) and various life stages of numerous ASFMC-managed species as shown in
Table 5.4 (e.g., American eel, black sea bass and gag grouper). All PNAs/SNAs serve as EFH for egg,
larval, and juvenile life stages of coastal migratory pelagics and shrimp, as can be inferred from
some species listed in Table 5.2. A barrier island forms a geomorphic buffer which can allow
extensive areas of PNAs/SNAs to occur behind it. However, the closest designated nurser y habitat
occurs ~29 miles away on the mainland in western Pamlico Sound (tributaries to Pains Bay and
Long Shoal River; Map 7 as shown on http://portal.ncdenr.org/web/mf/primary-nursery-areas) and
the nearest inlet which could transport fish to those PNAs is ~16 miles to southwest of the project
area. Therefore, this EFH/HAPC is not evaluated further in this document.

5.1.10 Unconsolidated/shallow subtidal bottom – this EFH consists of soft estuarine or marine
sediments inhabited by a diverse assemblage of invertebrates that serve as prey to demersal fishes.
Some managed species that require this essential habitat include, bluefish, red drum, snapper
grouper, spiny lobster, summer flounder, smooth dogfish, and numerous shark species. Typically,
very mobile in response to wave and current conditions, these sediments lack stable surfaces for
extensive vegetation or animal attachment. Changes in type or amount of sediment supply, energy
of wave and currents, and changes in water quality chemistry drive the biodiversity within this EFH.
In the project vicinity, this EFH is found beneath both estuarine and marine waters, but for the same
reasons given for other estuarine EFHs above, only the marine sediments of this EFH will be
evaluated further. The offshore component of this EFH is typically more taxa rich than the surf zone
and nearshore components because of differences in sediment transport forces and the dynamics
of breaking waves in the surf zone. Marine EFH of this type is found both within the project vicinity
(within 2 miles of project area) and within the project area itself (proposed borrow areas and Avon
beach intertidal beach/surf zone).

5.1.11 Cape Hatteras shoals – these shoals are part of the sandy shoals of capes and offshore bars
EFH for Coastal Migratory pelagics, Highly Migratory Species, and summer flounder, a habitat of
concern for red drum, and HAPC for sandbar shark. Such shoals include the marine soft bottom
community identified and discussed in the CHPP (Deaton et al. 2010 and NCDEQ 2016a,b). Diamond
Shoals at Cape Hatteras are a major sink in the coastal sediment transport system and are formed by
convergent waves and longshore currents associated with cuspate forelands (Moslow and Heron
1994). The shoals are fed by sand moving south along the north segment of Hatteras Island under

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predominant northeast winds and waves, and sand moving east along the southern arm of Hatteras
Island under prevailing southwest winds and waves; as such the individual features (ridges and
troughs) shift in response. Diamond Shoals encompass over 15,000 acres of shoal habitat (an area
approximately 7 by 2.5 nautical miles extending southeast from Cape Point beginning ~12,000 ft
south of the project area. A continuous supply of sand from adjacent beaches feeds Diamond Shoals
and maintains them as an underwater extension of the coastline (Armstrong et al. 2013). Diamond
Shoals contains roughly 100 times the volume of sediment in the proposed borrow areas within the
upper ~ 8 ft of substrate.

Cape Hatteras also marks a convergence zone where the southerly flow of the Labrador Current
meets the northerly flow of the Florida Current/Gulf Stream and where the Florida Current separates
from the continental shelf and the flow becomes the singular Gulf Stream, and where the current
begins its passage over the deep ocean. This dynamic zone of mixed oceanic waters marks a distinct
transition between warmer Gulf Stream waters and cooler Labrador waters with associated
upwelling of nutrient laden waters and changes in dominant species. For example, in a 4 February
2015 email to the author, Randy Swilling (Acting Division Chief, Resource Management at Cape
Hatteras National Seashore) indicated that turtle nesting numbers per mile of shoreline decline north
of Cape Point; Paul Doshkov (Supervisory Biological Technician Cape Hatteras National Seashore)
confirmed in January 2021 that this trend continues. Cape Hatteras shoals represent the northern
and the southern terminus of the range of numerous species and results in a diverse biological
assemblage. These two currents deliver both warmer species from the south and cooler species from
the north to the shoals in the area and adjacent habitats. These shoals support seasonal
congregations of baitfish and shrimp preyed upon by numerous managed species (e.g., red drum and
Spanish mackerel) and serve as staging areas for other coastal migratory species. The named shoals
further north of Cape Hatteras and the proposed borrow areas (Wimble and Kinnakeet) serve as
spawning habitat for summer flounder aggregations (MAFMC 1998, Deaton et al. 2010, NCDEQ
2016a,b). Nearshore ocean waters and subtidal bottom habitat also serve as important pupping
areas for several species of small coastal sharks (e.g., Atlantic sharpnose, bonnethead, blacknose
shark); larger coastal sharks pup in these areas to a lesser extent. Acoustical arrays deployed south
of Cape Hatteras (2008-2011 and 2012-2014) demonstrated how the shoals acted to constrict both
shelf habitat and the migratory corridors of several highly migratory and/or managed species whose
acoustic tags were tracked (e.g., spiny dogfish, Atlantic sturgeon, and sandbar shark) into this narrow
convergence zone (Rulifson et al. 2020). Some tagged Atlantic sturgeon remained in the area all year
and other Atlantic sturgeon and some shark species remained in the area only during the winter
(November to April was shown as most critical period for these wintering species) (Rulifson et al.
2015). While not considered to be within the nearby Kinnakeet Shoals found north of the project area,
the smaller sand ridge targeted within proposed borrow areas does appear to be oriented shore
oblique along a similar axis as shoals north of Cape Hatteras and likely formed under similar dynamics
and performs similar functions (fig 5.10).

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FIGURE 5.10. From Mallinson et. al., 2009, which shows Wimble and Kinnakeet Shoals to the north;
the smaller ridge feature 2–3 miles south of Kinnakeet Shoals is the isolated ridge of the proposed
borrow areas.

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6.0 POTENTIAL EFFECTS TO EFH, EFH-HAPC, OR LIFE STAGES OF ASSOCIATED MANAGED FISH

Adequate information over local and regional spatial scales is needed to accurately predict the
direct and indirect impact of beach nourishment on the target beach ecosystem or on the borrow
areas and to ensure such activities are ecologically sound. However, while scientific understanding
continues to deepen for some species or habitats, well-conceived and easily comparable pre- and
post-impact studies are scarce (Schlacher et al. 2008; Leewis et al. 2012). Increased development
of barrier islands and increased erosion of low-lying barrier island segments without adequate
dunes have resulted in dredging (both inlet maintenance for navigation and excavation of offshore
sites) and beach placement of dredged sediments as common practices in coastal North Carolina.

About 50 percent of the 326 miles of ocean shoreline in North Carolina is state or federally owned.
Approximately 85.3 miles (~26 percent) of the shoreline have been nourished at least one time, an
estimated total of 167 miles (51 percent) have either received nourishment or are being considered
for nourishment sometime in the future, and the average renourishment interval has been 4.5 years
(Moffat & Nichol 2016). The statewide annual volume of nourishment projects has increased from
2.1 million cy/yr over the entire record to 4.1 million cy/yr since 2005 and 4.6 million cy/yr since 2010
(Moffat & Nichol 2016). A similar increase is shown in the total annual distance nourished statewide
from 4.6 mi/yr over the entire record to 10.9 mi/yr since 2005 and 11.5 mi/yr since 2010 (Moffat &
Nichol 2016) This means that in a given year, ~6 percent of the North Carolina coast has been subject
to beach reconstruction over the past several decades. If future renourishment intervals remain
the same as the past, potential additional areas considered for nourishment may increase the
proportion of beaches actively nourished in a given year to ~11 percent.

The construction duration of nourishment for any single project is typically ~3 months. Potential
effects to marine resources (including food sources and various life stages) or their habitats from
dredging or placement of sediments may include some or all of the following: temporary or more
permanent changes in coastal biogeochemistry processes and conditions (Hannides, Elko, and
Humiston 2019), reduced food availability, direct habitat removal or burial, increased water column
turbidity, dissolved oxygen reduction, contaminant and nutrient release, character changes in
benthic sediment, character changes in benthic composition of infauna, suspension and dispersion
of infauna, and entrainment. The potential effect varies from project to project and is dependent on
methods, frequency, season, location, and the marine resources present in the project area.

Over the past few decades, improved methods, equipment, and techniques used by dredge
companies, project design improvements, sustained interagency collaboration and coordination,
establishment of sediment criteria, regional planning, and specific permit conditions have all
contributed to the minimization of many of these potential effects. Largely due to these
improvements and collaboration, , the Wilmington District Corps of Engineers determined that
most beach nourishment projects in North Carolina can be properly evaluated with a detailed
Environmental Assessment/Finding of No Significant Impact (EA/FONSI) instead of an
environmental impact statement. Additionally, effects on protected resources of many such
projects can be considered and potentially permitted under the new South Atlantic Regional
Biological Opinion for Dredging and Material Placement Activities in the Southeast United States
(2020 SARBO) (NMFS 2020).

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6.1 EFH and HAPC
Table 5.5 lists the EFH categories and geographically defined HAPCs in those EFH within the project
area or vicinity. Only those categories/features in the Impact Activity columns in Table 5.5 which
have designations other than N (for No potential impact) are discussed below with emphasis on the
SAFMC resource specifically designated to that EFH or HAPC as shown in Table 5.3. Attachment A
contains descriptions of both cutterhead and hopper dredge equipment, potential sedimentation
and turbidity effects from their operation, and a summary table of minimization measures. Some
of the minimization measures were extracted from the final EFH Assessment for the Emergency
Beach Fill Along NC Highway 12 in Rodanthe, Dare County, North Carolina (Sections 13.1 and 13.2
and Table 4 from USACE 2013 which was also the minimization template for the 2017/2018 Buxton
restoration project while other minimization measure shown are from the 2020 SARBO. For
additional details on differences between dredge types and the summary of various methods to
reduce impacts, please refer to Attachment A.

While the purpose of this assessment is to address project specific impacts to EFH/HAPC, a suite of
large scale dynamics and changes in relationship patterns across trophic levels of the southeastern
US Atlantic coastal environment attributed to climate change are also likely to impact living marine
resources which depend on EFH/HAPC in various ways and at an unknown pace. Natural long-term
variability in the region and response to such larger scale drivers is not well understood; but
obviously large scale oscillations in oceanic circulation influence ecosystems in complicated ways.
Among other noted climate changes which impact EFH/HAPC (e.g., increases in temperature, sea
level, and acidity), some researchers opine the Gulf Stream also appears to be weake ning, along
with its associated Atlantic Meridional Overturning Circulation (AMOC), which may have
implications for primary and secondary productivity if this weakening results in a decline in
duration, magnitude, or frequency of Gulf Stream-associated upwelling events (per Ezer et al. 2013
and Rahmstorf et al. 2015 in NOAA 2017b). Indirect effects of temperature change may also be
important. For example, small increases (~0.6 ºC) in temperature have been associated with major
changes in planktonic ecosystems in the North Atlantic (Richardson and Schoeman 2004). Since
plankton is essential for suspension-feeding beach species, changes in plankton assemblages may
have large effects on these beach species and certain surf zone species which may prey upon them.
Coincident to oscillations of ocean currents, climate change is purported to be associated with an
increase in extreme events (e.g., hurricanes) which, even if they do not make landfall, the repeated
associated high surf and elevated rainfall can be disruptive to nearshore species. The The NC coast
experienced these effects from four hurricanes in 2017 (Irma, Jose, Katia, and Maria), a series of
nor'easters in March of 2018, a hurricane in 2018 (Florence), and a hurricane in 2019 (Dorian).

There is a pervasive notion in the media and in scientific literature of an increase in jellyfish
“blooms” and an increase of dominance of nuisance jellyfish as additional evidence of a decline in
the health of the world’s oceans (Condon et al. 2012 and 2013). Of pertinence to the Proposed
Action, record numbers of cannonball jellyfish in nearshore NC waters in summer 2017 complicated
the collection of borrow sediments for three northern Outer Banks beach nourishment projects.
Cannonball jellyfish are preferred prey for leatherback sea turtles and there was an unexpected
increase in sea turtles during the dredge operations for those projects. An oceanic condition or
circulation pattern that kept the Gulf Stream closer to shore would explain the increase in turtles
which tend to expand their range in association with warmer waters (Personal communication, Dr.

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2403M–Task 4–Appendix F] 53 Avon Village, Dare County, North Carolina

David Kimmel, Lead Researcher Oceanographer, EcoFOCI, Alaska Fisheries Science Center, NMFS,
NOAA, 21 September 2017; former faculty member East Carolina University).

To investigate the notion of increased jellyfish blooms, Condon et al. 2013 gathered all available
published and unpublished long-term time-series on jellyfish abundance across the oceans for over
a century from 1874. The study identified two patterns in jellyfish populations: (i) a weak but
significant overall increase in jellyfish since 1970, and (ii) a strong recurrent pattern of oscillations
that has persisted for over a century. As stated by Condon et al. (2013) the realization that jellyfish
populations have been pulsing globally at decadal scales should lead to a broadening of the search
for the drivers of change, from regional-scale (e.g., hypoxia) to global drivers (e.g., climatic
oscillations). Among the suspected drivers are global temperature increases (Purcell et al. 2007
and Purcell 2012), overfishing of competitors (by-catch and reduction of predators in Daskalov et
al. 2007), eutrophication of coastal waters (Parsons and Lalli 2002), spread of hypoxia (Vaquer-
Sunyer and Duarte 2008; Purcell 2012), and human activities along the coast (Duarte et al. 2013).

Among the complex ecological interactions between the ocean and the atmosphere, climate
variability also has differential influences on sex and size classes (Stenseth et al. 2002), w hich can
also affect food webs in various ways. The biological characteristics of small pelagic fish, prey to
some managed species, are highly sensitive to environmental fluctuations (Alheit and Hagen 2001
in Stenseth et al. 2002). In addition, other planktivores (e.g., some forage fish and jellyfish)
demonstrate rapid fluctuation in population size in response to multi-scale (seasonal to decadal)
variables in the environment due to their dependence on primary and secondary production cycles
(Purcell 2005, Pikitch et al. 2012, in Robinson et al. 2014). As stated in Robinson et al. (2014) large
scale climate driven effects such as the North Atlantic Oscillation (NAO) can indirectly affect the
timing, magnitude, and distribution of planktonic production in the Atlantic Ocean (Fromentin and
Planque 1996). The NAO influence on ocean conditions (Hurrell et al. 2003) affects the planktonic
production that supports larval and adult forage fish (Alheit and Hagan 1997; Pitois et al. 2012;
Paiva et al. 2013) and jellyfish (Lynam et al. 2004, 2011; Molinero et al. 2005).

While much is known, much more remains to be known before attribution (non -human or human)
of the specific cause of apparent or measured effects and accurate quantification of impacts can
be confidently made. Nonetheless, a balance between sustainable fisheries management and
the pressures exerted from human coastal activities on those fisheries remains the goal of
interagency consultation, international engagement, and continued research on antagoni stic
and synergistic drivers of change and the magnitude or frequency of ecosystems’ or species’
responses to those changes .

6.1.1 Sargassum - pelagic Sargassum is positively buoyant and, depending on the prevailing
surface currents, remains in waters of the continental shelf for extended periods or can be cast
ashore when storm currents and wind allow such onshore/nearshore transport. Therefore, pelagic
Sargassum species could drift through the vicinity of the dredge operation in the proposed offshore
borrow areas or, depending on wind and currents, could drift into the nearshore or surf zone.
Because it occurs in the upper few feet of the water column, it is not subject to direct effects from
dredging, although sediment placement activities associated with the proposed project could
introduce temporary turbidity in the shallow water column during sand placement. However, this
turbidity is short-lived and will likely duplicate storm conditions; thus, no impacts are expected to

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this EFH or its associated managed fish species from turbidity. Juvenile fish or other organisms
associated with Sargassum may serve as food for managed fish when any mats have floated into
the nearshore or surf zone; species already in the nearshore/surf zone water column may also use
the mat as refugia. If floating mats are encountered during dredging or are washed ashore during
sand placement and are buried, these mats would represent a very small portion of the total EFH
or EFH-HAPC available. Since Sargassum occurs in the upper few feet of the water column and is
not commonly found in the project area, the project is not expected to have any impact on this
EFH or HAPC or the life stages of managed species which utilize them; any impacts that may
occur are expected to be minor and within acceptable limits.

6.1.2 Marine water column (includes ocean high salinity surf zone) – this EFH is found above
topographically and hydrodynamically distinct habitats that support correspondingly distinct fish
and benthic assemblages. Dredging and sand placement activities conducted during project
construction will occur in the marine water column in the immediate vicinity of the borrow areas
and the target beach which have the potential to impact nearshore and intertidal surf zone
resources of larval, juvenile, and/or adult life stages. These impacts may include minor and short -
term sediment plumes (and related turbidity) as well as the release of trace constituents from the
sediment into the water column. Marine sediments can be sinks/reservoirs for various pollutants
most typically sourced to atmospheric or riverine deposition. Trace constituents found in the
sediments which may be released into the water column during dredging or sand placement
activities in connection with beach nourishment projects are usually associated with source
sediment having proximity to either an active or old port, wastewater treatment facilities, effluents
from industries, or undocumented spill of pollutants. Additionally, important nutrients can
accumulate in various soft bottom sediments and be reintroduced into the water column when
disturbed. Although it could possibly contain constituents from an unknown spill, proposed
offshore borrow areas is a naturally formed, sandy high energy shoal located at considerable
distance from a port, inlet, or known effluent source so it is unlikely to release harmful
contaminants or nutrients during dredging or placement activities. The borrow areas are regularly
exposed to waves greater than 10 ft and generally exhibits only trace amounts of fine-grained clays
to which contaminants can adsorb.

Other effects from turbidity in the water column would include changes in light penetration and
visibility which may be either beneficial or problematic (whether predator or prey) and can interfere
with nutrient availability for filter-feeders. Because the proposed borrow areas consist of >99%
sandy or shelly material, settling of sediments placed into suspension during dredging operations
is expected to be rapid and measured in minutes, returning the borrow areas to ambient conditions
soon after cessation of operations. The fishes of the ocean high salinity surf zone are adapted to
frequent and naturally turbid habitat conditions; higher turbidities which occur during sand
placement operations of the proposed project will be of shorter duration than many common
weather events.

Turbidity in the water column from beach placement of sand may create localized stressful habitat
conditions and may result in the temporary displacement of fish and other biota. Given the high-
energy offshore environment and the coarse sediment composition, the turbidity plume created is
expected to be short-lived. Coarse sediments have much higher settling velocities than finer
material (Table 6.1). Fine-grained sediments (such as silts and clays) produce greater and longer

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lasting turbidity plumes, which can impact large areas of the sea floor more than coarser, sand-
sized material (USACE 2002a). Suspended sediments settle at predicted rates dependent on grain
size as shown in Table 6.1 below. The time necessary for sediments in the turbidity plume to settle
whether in suspension from dredge activity, in the slurry itself, or resuspended during manipulation
is also affected by current and wave climate in the borrow areas during dredge activity and in the
intertidal zone during placement and manipulation. While turbidity plumes associated with
dredging are often short-lived and may affect relatively small areas, subsequent resuspension and
redispersal of dredged sediments can propagate beyond the dredged area for extended periods in
certain wave climates (CSA International et al. 2010). However, these effects are minimal in sandier
offshore areas such as the high energy shoal of the proposed borrow areas.

TABLE 6.1. Sediment settling velocities. [ds- sieve diameter. dv- volume sphere
diameter. df- sedimentation diameter. *Wentworth Classification.]
ds
(mm)
dv
(mm)
df
(mm)
@ 10°C
(m/sec)
@ 20°C
(m/sec)
*Sand
Classification
0.089 0.10 0.1 0.005 0.007 vf
0.126 0.14 0.14 0.010 0.013 vf-f
0.147 0.17 0.16 0.013 0.016 f
0.208 0.22 0.22 0.023 0.028 f
0.25 0.25 0.25 0.028 0.033 f-m
0.29 0.30 0.29 0.033 0.039 m
0.42 0.46 0.40 0.05 0.058 m
0.59 0.64 0.55 0.077 0.084 c
0.76 0.80 0.70 0.100 0.110 c
1.25 1.40 1.00 0.15 0.160 vc
1.8 1.90 1.20 0.17 0.170 vc

The impacts associated with this project from turbidity may be similar, on a smaller scale, to the
effects of storms. Storm effects also generally include increased turbidity and suspended sediment
load in the water column and, in some cases, changes in fish community structure (Hackney et al.
1996). Severe storms have been associated with fish kills, but such situations are not associated
with beach disposal of dredged sand. Turbidity will be most noticeable in proximity to the slurry
discharged from the pipe head which operates ahead of the beach building activities. The section
of beach affected per day will vary from 800 to 1,000 ft in length with 400 ft per day as the estimated
completion rate. Elevated turbidity levels were detected within up to ~500 ft down -current of the
discharge point along Nags Head during the 2011 project (CSE 2012). The discharge plume was
generally not detectable at greater distances.

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Van Dolah et al. (1994) assessed turbidity conditions associated with a beach nourishment project
at Folly Beach (SC), where native mean grain size is ~0.2 mm, and drew the following conclusion:

Although dredge effluent does increase turbidity levels in the immediate vicinity of the
outfall, there are many other factors such as local weather and wave energy that will also
produce this effect. The turbidity levels at Folly Beach during nourishment and the dispersal
of the sediment plume were not considered unusual or severe relative to normal fluctuations
and background levels.

As mentioned in USACE (2014) in their Environmental Report on the Use of Federal Offshore Sand
Resources for Beach and Coastal Restoration in New Jersey, Maryland, Delaware and Virginia (MMS
1999), the U.S. Department of Interior BOEM (previously MMS) provided the following assessment:

In order to assess if turbidity causes an impact to the ecosystem, it is essential that the
predicted turbidity levels be evaluated in light of conditions such as during storms. Storms
on the Mid-Atlantic shelf may generate suspended matter concentrations of several
hundred mg/L (e.g., Styles and Glenn 1999). Concentrations in plumes decrease rapidly
during dispersion. Neff (1981, 1985) reported that solids concentrations of 1000 ppm two
minutes after discharge decreased to 10 ppm within one hour. Poopetch (1982) showed that
the initial concentration in the hopper overflow of 3,500 mg/L decreased rapidly to 500 mg/L
within 50 m. For this reason, the impact of the settling particles from the turbidity plume is
expected to be minimal beyond the immediate zone of dredging.

Burlas et al. (USACE 2001) found that certain fish species (erg., kingfish) were attracted to higher
turbidity waters, whereas other species (e.g., bluefish) avoided high turbidity water around the
discharge pipe during a major nourishment project along the central New Jersey coast. This study
indicates that fish may seek as well as avoid locally turbid water associated with beach
nourishment and that the presence of elevated turbidity can repel, or even attract, certain species
dependent upon their particular adaptive behavior.

In addition to USACE 2001, other studies have also found insignificant impact or even a temporary
increase in surf zone fish populations associated with nourishment projects as possibly attributed to:

1) release of nutrients and infauna during dredging,
2) wide-foraging nature of surf zone fish, or
3) short term stay of migratory fish in the project area
(Deaton et al. 2010; NCDEQ 2016a,b).

So while highly migratory managed species such as bigeye, bluefin, skipjack, and yellowfin tuna all
have been documented as juvenile and adults in Hatteras Inle t and presumed to be in the waters
near Avon, it is unlikely these species will be affected by the associated turbidity of the proposed
project. The representational data set, NCDMF recreational catch data from 2004 -2019, show tuna
in those intercepts from 0-3 miles from shore; tuna comprised 8.6 percent of the 17,897 total fish
with 5.7 percent of the tuna catch unidentified to species. Of potential interest, recent satellite
tagging data on spiny dogfish (one of the most abundant sharks in the world and long-lived)
indicate that benthic trawl data may not accurately represent the status of the species as

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unexpected movement patterns shown by the tagged fish demonstrates that spiny dogfish utilize
more of the marine water column than previously thought making them less available to benthic
gear (Carlson et al. 2014). In North Carolina shelf waters, spiny dogfish are most common from
November to April. Pregnant female spiny dogfish and pups are present from February through
June and have a preferred pupping area located in the vicinity of Cape Hatteras shoals (MAFMC
2014). Adult bluefish occur in Mid-Atlantic estuaries from April to October and juveniles occur from
May to October (http://www.habitat.noaa.gov/protection/efh/newInv/index.html). Young of the
year (YOY) also are common in proximity or within the project area marine water column and ocean
high salinity surf zone north of Cape Hatteras as shown in Figure 28 in the 2000 Amendment 1 to the
Bluefish FMP (MAFMC, 2014).

Odell et al. (2014) list turbidity from beach nourishment and potential release of toxicants as a
medium threat for red drum, juveniles of which eat zooplankton and small invertebrates. Little has
been published on effects of beach nourishment on surf zone biota since North Carolina established
sediment criteria for such projects in 2007; even fewer have been published with a BACI
(before/after/control) component. In one of the few such publications, significant variation of
abundances of zooplankton among sample time/site suggested potential effects of beach
nourishment, seasonality, recruitment, planktivory, and surf zone turbidity on zooplankton
populations (Stull et al. 2016). Turbidity was hypothesized to be an index of disturbance by high
surf or human activities by Stull et al. (2016); however, linear regressions demonstrated that mean
zooplankton abundance plotted against surf zone turbidity was not significant for any of the
zooplankton groups or taxa. In addition, while effect of beach nourishment on zooplankton was
explored numerous ways by Stull et al. (2016), no consistent long-term positive or negative effects
of beach nourishment history and no significant effects between 1 to 2 weeks before or 2 to 3 weeks
after nourishment were detected. According to Stull et al. (2016), the abundance of zooplankton
measured in their study supported an earlier study (Delancey 1989) which concluded zooplankton
were an important food source for surf zone planktivores and also concluded that contrary to
previous studies, beach nourishment activities in the surf zone may represent transient short lived
disturbance in a naturally frequently disturbed environment.

Fish larvae in the ocean waters near Oregon Inlet generally travel westward until they encounter
the shoreline then migrate along the shoreline until they encounter the inlet (USACE 2002b). As
stated in the EFH assessment prepared for the Rodanthe project (USACE 2014) larval ingress and
egress studies suggest that larval transport from offshore shelves to estuarine nursery habitats
occurs in three stages: offshore spawning grounds to nearshore, nearshore to the locality of an inlet
or estuary mouth, and from the mouth into the estuary (Boehlert and Mundy 1988). Results from
the Hettler and Hare 1998 study suggest two bottlenecks for offshore-spawning fishes with
estuarine juveniles: the transport of larvae into the nearshore zone and the transport of larvae into
the estuary from the nearshore zone. While the methods fish larvae use to cover large distances
over the open ocean and find the inlets to their estuarine nurseries is uncertain, both passive and
active methods of movement are suspected along with use of environmental cues such as salinity,
depth, temperature, swells, etc. Various studies have hypothesized passive wind and depth-varying
current dispersal and active horizontal swimming transport. However, data are limited regarding
larval distribution in the nearshore area. As indicated in USACE (2014), population level
calculations of larval entrainment from hydraulic dredging activities were insignificant within a
representative high concentration inlet bottleneck at Beaufort Inlet, North Carolina. Therefore, the

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risk of larval entrainment from dredging activities in the offshore borrow areas associated with this
project would likely be even less. However, some larvae in the marine water column adjacent to
the beach could be buried or injured during sand placement activities but not in numbers that
would have a long-term effect at the species level. Diamond Shoals lies between the Avon project
area and Hatteras Inlet (the nearest inlet). Currents and waves associated with these large shoals
act as a barrier to longshore transport which naturally converges toward Diamond Shoals (Deaton
et al. 2010; NCDEQ 2016a,b) and therefore likely divert seaward a component of larvae drifting in
the littoral current in the Avon vicinity.

Very few peer-reviewed papers have discussed responses of fish larvae or eggs to man-made
sounds and while many other factors may be at play in responses of juveniles and adults to man-
made noise or to any long-term consequences, one of the most important will be largely
determined by presence or absence of a gas bladder (Popper et al. 2014). Gas bladders, along with
their location within the body, make fish more susceptible to pressure-mediated injury to the ears
and other tissues than those without and allow fish to detect a broader frequency range and at
greater distances (Popper et al. 2014). Most bony fishes have gas bladders while the more primitive
cartilaginous fishes (sharks and rays) do not. Some of the problems of previous research come from
the fact that the subjects were captive fish in laboratory conditions and almost no ne have
emphasized study of fish responses to particle motion rather than to sound pressure. Despite
recent interest and increased concern, wide information gaps make it very difficult to draw
conclusions about the nature and levels of man-made sounds and their potential to cause harm on
fish, turtles, or invertebrates (Hawkins et al. 2014, Popper and Hawkins 2018 and 2019).

For the reasons described above, marine water column EFH including the surf zone EFH will
experience temporary turbidity from both the dredge operation and the sand placement activity
along with the potential for some fish or benthos larval death and/or injury from turbidity; however,
mobile juvenile and adult fish species have the ability to locate away from the most disruptive
activities. Noise levels may result in avoidance behaviors in some mobile fish species but levels
are not expected to cause hearing damage. Temporary interruptions to feeding activities of fish
that predate on the benthic invertebrates may occur but these interruptions are minor since large
expanses of similar habitat are nearby. These effects are not expected to be long lasting or cause
significant impact to this marine water column or ocean high-salinity surf zone EFH or the life
stages of managed species found within these habitats.

6.1.3 Hard bottom – The only hard bottom habitat in the project footprint is the Avon Pier, a pile
supported structure in sand. Remnants of three groins provide hard bottom habitat ~5 miles south
of the proposed Avon project in the vicinity of the old Cape Hatteras Lighthouse site. The Avon
project will place sand under the pier to provide a continuous nourished beach either by direct
pumping or natural spreading by waves from either side of the pier. This action will cause burial of
sersile organisms such as barnacles which attach to pier pilings, and displacement of organisms
which forage on attached plants and animals. Such displacements and burial are unavoidable.
However, the increased beach width (in the order of 50-100 ft) represents less than 15% of the pier
length. Surf zone intertidal organisms are expected to repopulate around the pier seaward of the
pre-nourishment shoreline and continue adapting to the dynamic beach cycle of onshore-offshore
transport and turbidity associated with the surf zone. Visually oriented capture of prey may be
temporarily disrupted for some fish, but turbidity also provides increased cover for others. Any

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turbidity that does occur is likely to be of shorter duration than that associated with some weather
events but nonetheless could affect some of the filter-feeder colonizers which provide refuge or are
prey to managed fish of the surf zone. These effects are not expected to be long-lasting or cause
significant impact to hard bottom EFH or the life stages of managed species which may be in
the vicinity.

6.1.4 Unconsolidated/shallow subtidal bottom (marine only) – this EFH is extensive and
includes all areas of submerged or intertidal bottom seaward of the beach not considered hard
bottom. This EFH provides large areas of nursery and foraging grounds for managed fish (e.g.,
bluefish, sharks, tunas, summer flounder, and smooth and spiny dogfish) and invertebrates and
smaller forage fish upon which managed species depend at various life stages. Subtidal soft
bottom may contain up to 600 benthic species, the intertidal zone of the lower beach is diverse with
meiofauna, but the beach benthic community is primarily composed of 20 to 50 species of
macrofauna (Deaton et al. 2010 and NCDEQ 2016a,b).

Dredging of sediments in the offshore borrow areas will disturb and dislodge benthic organisms
and either cause mortality from burial or entrainment, or disrupt their normal behaviors during the
disturbance window. Benthic dependent fish in the area, and/or their predators, along with various
life stages of other managed species may also experience entrainment mortality (eggs and larvae
are particularly likely to suffer lethal effects due to dredge processes) or avoidance behavior effects
due to noise or turbidity, or physiological effects such as clogged gills and visual impairment as
suggested in the schematic below (Fig 6.1). In ASMFC’s Habitat Management Series #14, beach
nourishment and dredging were rated as medium threats for benthos dependent species such as
red drum (due to changes in prey community, preferred substrate changes and burial of
individuals) while climate change and coastal development were rated as high (Odell et al. 2017).
Beach disposal of the dredged sediments can affect fishery resources through burial of intertidal
and surf zone resources that managed fish may utilize. However, some demersal fish species are
sometimes attracted to this type of disturbance (northern kingfish) and feed on the numerous
fauna that may be suspended in the water column from the dredging or disposal activity. Other
more sensitive demersal species can opt to move away to adjacent feeding areas (bluefish). While
Deaton et al. (2010, page 364) acknowledge “the relative quick recovery on intertidal and shallow
subtidal benthic communities” associated with soft stabilization projects on oceanfront shorelines
such as bulldozing, without adequate best management practices known to enhance biological
recovery, recovery rates in mined areas are usually longer. Periodic storms affect benthic
communities along the Atlantic coast to a depth of about 115 ft (35 m); therefore, the soft bottom
marine benthic community tends to be dominated by opportunistic taxa that are adapted to
recover relatively quickly from disturbance (Posey and Alphin 2001; Posey and Alphin 2002 in
Deaton et al. 2010; and NCDEQ 2016a,b).

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While not specifically designated as EFH, HAPC, Primary Nursery Areas (PNAs) or Strategic Habitat
Areas, Rippled Scoured Depressions (RSDs) and Rippled Channel Depressions (RCDs), are
recognized as important soft bottom habitat and such features provide a diversity of structure for
fish and benthos in the nearshore and surf zone environment (Deaton et al. 2010). As a nourished
beach equilibrates, sediment placed in the targeted nourishment zone could gradually move within
these nearshore RSD/RCD features which shift seasonally in response to wave action. However, as
stated in USACE (2014), Thieler et al. (1999 and 2001) demonstrated it is likely that the features
would be maintained through the self-reinforcing pattern in response to both along- and across-
shore flows independent of beach nourishment activities. Therefore, benthic organisms normally
associated with fine- and coarse-grained sediments in the nearshore component of this EFH are not
likely to be significantly altered by the project. Nevertheless, during equilibration, removal of these
runnels in the surf zone might eliminate the physical refuge these features provide for plankton and
nekton. Despite the long held hypothesis that juvenile fish abundance in the gutters and runnels
was evidence of restricted movement and forage efficiency for predators, in a global review of fish
ecology of the surf zone, Olds et al. (2017) listed several studies which challenge that hypothesis.
As the preponderance of the published literature they reviewed (72 out of 151) is descriptive, 26
addressed how environmental conditions affect fish assemblages, and only seven addressed
habitat modification, the need for empirical data to test several common hypotheses about the surf
zone was also evident.

FIGURE 6.1. Characteristics of fish that make them vulnerable to effects from dredge processes.
(source: Figure 1 in Wenger et al. 2017)

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Managed species, whether piscivorous or not, are attracted to this EFH largely due to its use by their
preferred food, a process driven by the dynamics of a typical food web which is built from the
bottom to the top and largely dependent on the benthic community in the unconsolidated
sediments. Spatial and temporal variation in the benthic community prey species can therefore
affect growth, survival, population levels of predators and all higher trophic level species
(Normandeau Associates 2014). The annual and seasonal variability in the benthic community of
this EFH is well documented and when subject to storms during a monitoring period (hurricanes or
nor’easters common to the Outer Banks) project effects can be difficult to discern with confidence
(Deaton et al. 2010, NCDEQ 2016a,b). However, known factors which maximize bent hic biological
recovery rates in the offshore portion of this EFH include use of hopper dredges, shallow
excavation, use of topographic highs, and rate of sand movement. In US Gulf and Atlantic sandy
borrow areas studied within BOEM jurisdiction, general faunal recovery (total abundance and
biomass) has been shown to vary from 3 months to 2.5 years; however, paucity of long term studies
suggest that diversity and dominants composition may take 3.5 years (Michel et al. 2013). Those
factors which maximize recovery in the beach intertidal zone include the following:

 Grain size (similarity between native beach and borrow source is considered the most
important factor; this compatibility is the main component of the sediment criteria
requirements in North Carolina in place since 2007),
 Season of nourishment (winter placement avoids peak recruitment periods),
 Frequency of nourishment (allow for growth to maturity across years),
 Location of sediment placement (maintain stable geomorphology across the normal
beach seasonal profile to ensure sand remains in the system as long as possible), and
 Rate of longshore transport (upstream recruitment opportunity).

No infilling fines in the borrow area and accurate placement of properly sized sediment at Nags
Head Beach in 2011 allowed a full suite of species similar to the native beach and offshore zone to
recolonize the impact areas within one season and by the second year taxa richness and
abundances were similar to controls (CZR 2014).

In such environments frequently disturbed by natural events, infauna are well adapted to such
perturbations by being small bodied, short lived, with a maximum rate of fecundity, efficient
dispersal mechanisms, dense settlement, and rapid growth rates. Burial or temporary exposure
from dredging could also be beneficial or problematic depending on species and niche (a more
mobile fauna may be able to dig vertically to the new surface and avoid burial and less mobile prey
species temporarily exposed may provide more available food source for predator species).
Dredging in the borrow area and sand placement on the beach may temporarily disrupt food webs,
change predator-prey relationships, reduce community stability, and change age structure of
populations by selective mortality. However, it is recognized that tube dwellers and permanent
burrow dwellers are most susceptible to these types of disturbances compared to more mobile
organisms. A study of 50 dredge and disposal projects concluded that benthic recove ry measured
in months was associated with shallow, naturally disturbed habitats, unconsolidated fine grain
sediments, and univariate analytical approaches while longer recovery (years) was associated with
deep stable habitats, sand and gravel sediments, and multivariate or functional group analytical
techniques (Wilber and Clarke 2007). This same study also noted that absence of both deposit
feeders and of mid-depth burrowers may indicate an area is in a state of recovery. Polychaete

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worms and crustaceans recover most quickly (several months) while deep burrowing mollusks are
slower and may take several years (Rutecki et al. 2014 and Brooks et al. 2006, respectively).
However, while polychaetes comprise the larger component of soft sediment infauna, a complete
life history is known for only about 5 percent of the >8,000 described polychaete species (Ramey
2008). Additionally, studies have shown that avoidance of the peak larval recruitment period (early
spring in the eastern US) can have a beneficial effe ct on the recovery rate (Wilber, et al. 2009); the
Avon beach nourishment is proposed to occur in the summer. On a spatial scale that far exceeds
the proposed offshore borrow areas shoal itself, another system driver that affects both speed and
diversity of biological recovery of a post-disturbance benthic assemblage beyond the resilience of
the species present is variability in supply, transport, and settlement of larvae for some species
(CSA International et al. 2010). While some disturbance, mortality, and burial will occur with
dredging and sand placement activities, these effects are not expected to be long-lasting or
cause significant impact to this EFH or the life stages of managed species which are found
within this habitat.

6.1.5 Cape Hatteras shoals/sandy shoals/offshore bars – the Cape Hatteras sandy shoals (a.k.a.,
Diamond Shoals) are located several miles south of the project area off Avon and extend for up to
14 miles-this complex is the closest designated HAPC to the project area. These unconsolidated
shoals are equivalent to soft bottom habitat as described in NCDEQ (2016 a and b). Geotechnical
data (CSE 2021) confirm there is uniformity of sediment size and type within the full section of the
proposed dredge cut, with similar quality surficial sediments expected to be left in place after
excavations of overlying material. These mobile soft sediments with various topographies serve as
congregation areas and secondary nurseries for many managed and commercially important fish
species that feed on benthic fauna [e.g., per NCDEQ (2016) –spiny dogfish, striped bass, and juvenile
Atlantic sturgeon] are known to aggregate off the Outer Banks in the winter. Of potential interest,
recent satellite tagging data on spiny dogfish indicate that benthic trawl data may not accurately
represent the status of the species as unexpected movement patterns shown by the tagged fish
demonstrates that spiny dogfish utilize more of the water column than previously thought making
them less available to benthic gear (Carlson et al. 2014).

Compared to larger named complexes like Kinnakeet Shoal, Wimble Shoals, or even the cape-
associated Diamond Shoals, the proposed offshore borrow site is a small somewhat isolated ridge;
however, the ridge and nearby flatter habitat provide complexity for some species of fish and
invertebrates. Site specific information about the fish and invertebrates found within the proposed
borrow areas was not located, but biological resources which may be common in the area can be
inferred. Any vertical relief can provide refugia for an abundance of potential prey which then
affords more suitable foraging ground and likely attracts more predators. A deeper understanding
and appreciation for the diversity of demersal and pelagic fishes associated with shoal complexes
has been gained with recent studies in the Mid-Atlantic Bight (predominantly north of Maryland)
and support their designation as EFH (e.g., pelagics such as bay anchovy, Atlantic menhaden,
Atlantic mackerel, butterfish, striped bass). Potential feeding, spawning, and maturation can take
place in these habitats during fall and spring migrations of numerous managed and unmanaged
fish species, especially those behaviorally and morphologically adapted to bottom feeding in
sedimentary environments (skates, scups, drums, searobins, black sea bass, flounders) CSA
International 2010).

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The water depth in shallowest portion of the proposed Avon borrow areas range from about 30 to
35 ft (9 to 11 meters) at the top of the ridge to about 40 to 45 ft (12 to 14 meters) in the flatter
topography on either side of the gentle slopes of the ridge. As described in the EFH assessment for
the 2014 nearby Rodanthe beach nourishment project, modeling performed for that project
showed that for shoals in water depths like the borrow area, waves more likely influence their
formation rather than currents (USACE 2013). However, the Avon borrow areas depths are at the
shallower end of the 10 to 30 m range of the model range. Another model suggests that post-dredge
infill of borrow areas is largely dependent on whether or not the ridge is active, whether or not there
is sand available for refilling, and the actual dredging location within the ridge (CSA International
et al. 2010). This model suggests that the best location for dredging on a shoal or ridge, at least
from a physical standpoint, is the leading, down-drift edge as the borrow scour area can then be
fed by ongoing physical (wave) processes which if active, are presumed to quickly refill the
borrowed area. This is expected to be the case for the Avon borrow areas given their location south
of Kinnakeet shoals. The ridge crest would be the second best, followed by the trailing edge. If the
ridge is not active, only larger scale processes, e.g., major storms will rebuild the ridge. The Dibajnia
and Nairn (2011) model referred to in the Rodanthe EFH assessment also tested various dredging
methodologies and subsequent reformation scenarios in order to suggest ways to dredge offshore
that would protect and maintain the morphologic integrity of ridge and shoal features; thereby also
affording protection of or reestablishment of benthos and fish habitat.

Only coarse grain sediment (≥90% sand) will be placed on the ocean beach strand in Avon and any
turbidity with this placement is not expected to extend to the Cape Hatteras sandy shoals or other
nearby shoals. However, turbidity associated with the removal of sediment from the proposed
offshore borrow areas will have short term impacts on the water column in the immediate vicinity
and potentially allow some settlement of fines to the bottom. However, the associated turbidity
effects from dredging in the borrow areas and from sand placement on the Avon beach will not
adversely impact the Cape Hatteras Sandy Shoals with altered longshore currents or altered tidal
climate.

Dredge operations on the unnamed shoal proposed as the offshore borrow will alter the geometry
of the existing sand feature which can alter benthic species recruitment patterns, especially if the
area refills with finer grained sediments. However, effects of these alterations will be minimized by
the method and location of targeted cutting such that portions of the habitat structure unique to
the feature and important to resource use will be maintained. A combination of physical and
environmental variables (e.g., temperature, depth, current facing versus lee side) as well as
differences in sampling season or gear type bias (otter trawl versus beam trawl) all contribute to
differences in cross-shelf species assemblage distributions among research studies of shoals.
Studies of shoals in the Mid-Atlantic Bight show higher diversity, taxa richness, and abundance
documented from the flats adjacent to shoals and according to Slacum et al. 2010 and winter as
the period of lowest finfish and invertebrate use of shoal habitat (Diaz et al. 2004, Slacum et al.
2010, and Normandeau Associates 2014). Vasslides and Able (2008) evaluated shoreface sand
ridges as habitat for fishes of the northeast coast and noted that shoreface sand ridges may have a
dis¬tinct influence on fish abundance and assemblages. Contrary to other studies which found
higher species richness and abundance in the surrounding inner shelf habitat (Diaz et al. 2004 and
Slacum et al. 2010), Vasslides and Able noted highest species abundance and richness on either
side of the sand ridge with distinct recreationally and commercially important species

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2403M–Task 4–Appendix F] 64 Avon Village, Dare County, North Carolina

assemblages. The fish found at the top of the ridge were typical prey species (sand lances,
anchovies, smallmouth flounder) favored by both resident and transient piscivores in the Mid-
Atlantic Bight (Chao and Musick 1977; Chase 2002; Walter et al. 2003; Gartland et al. 2006) and thus
sand ridges may influence the distribution of these economically important piscivores (Vasslides
and Able 2008). Anchovies and sand lances are among the 16 forage base species identified in the
previously mentioned 2017 MAFMC Unmanaged Forage Omnibus Amendment. This was the first
rule in the entire Atlantic to list forage species as ecosystem components. Sand lances are a unique
(they dive at swimming speed directly into the sand to avoid predators) and a very important forage
species to fish, birds, and marine mammals due to their streamlined elongate bodies which makes
them very easy to swallow. Despite their importance to the food web, like many of the ecosystem
component species, not enough is known about their biology or populations to inform
conservation or management (Staudinger et al. 2020).

Use of the topographic high and downcoast end within the proposed offshore borrow areas, overall
shallow excavation depth of the hopper dredge, and the borrow site’s location in an area of high
sand movement are important factors that will maximize biological recovery rates (Deaton et al.
2010; NCDEQ 2016a,b). Further, the area of the proposed borrow excavations represents less than
1 percent of the extant similar habitat available nearby in Diamond Shoals and Kinnakeet Shoals.
Therefore, the project is not expected to pose a threat to Cape Hatteras Shoals EFH or the life
stages of managed species which are found within this habitat; any impacts that may occur
are within reasonable limits.
6.2 Potential Cumulative Effects of Proposed Project on EFH and HAPC
The effect of multiple and cumulative past and future impacts to habitat quality can result in non-
linear or indirect responses of the fish which depend on particular habitats (ASMFC 2015; SAFMC
2009, 2016). Activities which may affect fish response include construction or navigation projects,
fisheries, and/or environmental or management conditions (e.g., degraded water quality, sediment
type shifts, climate change, switch to prey species when a managed fishery becomes overfished,
food web linkage disruptions, or trophic cascades). It is increasingly recognized that often the most
severe environmental effects may result from these cumulative and/or indirect effects especially
on mobile species (GESAMP 2019). Nevertheless, it is exceedingly difficult to accurately quantify
the habitat and relationship metrics for most species such that it can be said with confidence that
at X point of impact Y will occur if or when Z happens. One notable exception is the direct link of
anadromous fish abundance to river miles (SAFMC 2009; ASMFC 2015). Thus, this aspect of any
effects analysis remains a challenge.

To protect the Cape Hatteras lighthouse from erosion, in the 1970s three groins were placed in the
surf zone south of Buxton Village but these groins have not been maintained. With the exception of
sand bags permitted to be placed in front of 14 parcels in north Buxton Village in 2013, this highly
eroding segment of Hatteras Island has received no recent soft or hard stabilization. Prior to the
aforementioned 2017/2018 Buxton beach restoration project, the most recent nearby nourishment
project was NCDOT’s 2014 Rodanthe emergency nourishment which occurred 20 miles to the north
of the proposed Avon project. Depending on how time-crowded or space-crowded future offshore
dredging and beach placement operations were, cumulative effects could be harmful to managed
fishes and their habitats (marine water column, Sargassum, Cape Hatteras shoals) within the
borrow areas and/or the surf zone.

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2403M–Task 4–Appendix F] 65 Avon Village, Dare County, North Carolina

While NCDOT will continue to mobilize to protect NC 12 in emergency situations such as that which
occurred at the Rodanthe “S Curves” and Buxton, and which could occur at Avon, Dare County
officials would prefer to not wait for an emergency at Avon. Dare County government does have a
long-range beach nourishment plan that will eventually schedule and coordinate beach segments
in need of sand into a five-year rotation to ensure a more equitable use of available County funds.
Such a staggered and coordinated approach should eliminate the negative cumulative effects of
multiple projects which occur in close proximity, either spatially or temporally.

As post-nourishment beach invertebrate population recovery is most subject to similarity between
native and introduced sediments, NC adopted sediment criteria for beach nourishment projects in
the state in 2007. Geological models of shoal formation offshore have shown that as long as sea
floor irregularity remains on which to reform a ridge, dominant shelf processes will reconstruct
these features as predicted by the shelf ridge process models despite repeated dredge episodes
from the most desirable location or subarea (the crest, leading edge, or trailing edge) (CSA
International et al. 2010). To a dredge operator, from a physical standpo int, the most desirable
location of a shoal is the leading edge due to net long-term deposition and faster filling rates (CSA
International et al. 2010). Rates of transport and regional patterns of pathways of mobile sand are
generally understood for the proposed borrow areas but prediction of the pace of replenishment,
a return to a similar configuration, or benthic recovery is difficult.

Along with strict adherence to NC sediment criteria, additional offshore dredging and sand
placement mitigative practices for beach nourishment projects as shown in Table 4 of Attachment
A will also minimize the potential of cumulative effects to the EFH and HAPC. With the high quality
of the sediment selected for sand placement, little to no interruption to longshore or cross
shore sediment transport dynamics, one-time only strategic removal of shoal sands from the
proposed borrow areas, and the small amount of soft bottom, marine water column, hard
bottom, or sandy shoal in the action area relative to the amount of available other similar EFH
or HAPC at any time, the Proposed Action would not be expected to pose a significant
cumulative threat.

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[2403M–Task 4–Appendix F] 67 Avon Village, Dare County, North Carolina

7.0 EFH CONSIDERATIONS SUMMARY
Construction is expected to occur in the late spring -summer timeframe (i.e., May-September). The
following EFH considerations were developed in coordination with the NCDMF and NOAA Fisheries
during early project planning for the 2014 emergency project at Rodanthe, were followed for the
2017/2018 Buxton beach restoration project, and for the 2019 Nags Head renourishment, and will
be implemented for the proposed Avon beach nourishment project to the maximum extent
practicable:

1) promote quick benthic recovery through shallow borrow area excavation,
2) use topographic highs and/or areas of high mixing and winnowing of fines within the
proposed borrow areas,
3) encourage dredge operations that leave behind unimpacted "ridges" to allow for
recovery,
4) avoidance of hard bottom resources (within the nearshore toe of fill and offshore
borrow areas), and
5) construction of a temporary berm where necessary during placement on the beach
strand in order to minimize turbidity.

8.0 EFH IMPACT SUMMARY
The proposed Avon beach nourishment project would not be expected to cause any significant
adverse impacts to EFH or EFH-HAPC for those species managed by the SAFMC and MAFMC.

Coordination with representatives of NMFS and NCDMF will continue throughout the life of the
project in order to ensure that all parties are aware of any fisheries impacts. Additionally, both
NMFS and NCDMF will be provided with information from any required project surveys and
development of detailed borrow area use plans will be coordinated with both agencies.

The five Rodanthe EFH considerations listed above and followed by Buxton restoration (2017-2018)
will be integrated into the planning and eventually into the Avon beach nourishment project
construction process in order to minimize physical and biological impacts to EFH or HAPC and to
assure that any adverse effects are short term and localized on both an individual and cumulative
effects basis.

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[2525–Task 4–Appendix F] A-1 Avon Village, Dare County, North Carolina

ATTACHMENT A

HOPPER DREDGE AND CUTTERHEAD DREDGE INFORMATION
AND MITIGATION MEASURES (SECTION 13)
EXTRACTED FROM THE FINAL EFH ASSESSMENT
FOR
EMERGENCY BEACH FILL ALONG NC HIGHWAY 12,
IN RODANTHE, DARE COUNTY, NC
3 JULY 2013

and included in the

EFHA in support of the NEPA documents prepared for
2017-2018 Beach Restoration to Protect NC Highway 12
at Buxton, Dare County, NC
June 2015

NOTE: additional text added by CSE is shown in italics

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[2525–Task 4–Appendix F] A-3 Avon Village, Dare County, North Carolina

A.1 Cutterhead Hydraulic Pipeline Dredge - Sedimentation and Turbidity
Cutterhead hydraulic pipeline dredges are designed to handle a wide range of materials
including clay, hardpan, silts, sands, gravel, and some types of rock formations without
blasting. They are used for new work and maintenance in projects where suitable
placement/disposal areas are available and operate in an almost continuous dredging cycle
resulting in maximum production, economy, and efficiency. Cutterhead dredges are capable
of dredging in shallow or deep water and have accurate bottom and side slope cutting
capability. Limitations of cutterhead suction dredges include relative lack of mobility, long
mobilization and demobilization, inability to work in high wave action and currents, and are
impractical in high traffic areas. However, the dredging industry has shown itself to be capable
of developing innovative methodologies to work around some of these constraints.

Cutterhead dredges are rarely self-propelled and; therefore, must be transported to and from
the dredge site. Cutterhead dredge size is based on the inside diameter of the discharge pipe
which commonly ranges from 6” to 36.” They require an extensive array of support equipment
including pipeline (floating, shore, and submerged), boats (crew, work, survey), barges, and
pipe handling equipment. A cutterhead is located on the suction end of the dredge and is a
mechanical device that has rotating teeth to break up or loosen the bottom material so that it
can be sucked through the dredge (Fig A1, below; Figure 7 in 2013 source document).

During the dredging operation a cutterhead suction dredge is held in position by two spuds at
the stern of the dredge, only one of which can be on the bottom while the dredge swings , or an
anchor-cabling system that serves a similar purpose. The dredge swings around one spud or stern
cable position as it works the bottom. There are two swing anchors some distance from either
side of the dredge, which are connected by wire rope to the swing wenches. The dredge swings
to port and starboard alternately, passing the cutter through the bottom material until the
proper depth is achieved. The dredge advances by “walking” itself forward on the spuds. This
is accomplished by swinging the dredge to the port, using the port spud and appropriate
distance, then the starboard spud is dropped and the port spud raised. The dredge is then
swung an equal distance to the starboard and the port spud is dropped and the starboard spud
raised. For ocean borrow areas, a cable bridle system is generally preferred over a spud system to
allow better seakeeping as work progresses.

Moving cutterhead suction dredges is a slow process; therefore, efficiency is maximized by
dredging in localized areas with deeper dredge cut volumes where the cutterhead is buried in
the bottom. A cutterhead removes dredged material through an intake pipe and then pushes
it out the discharge pipeline directly into the placement/disposal site. Most, but not all,
cutterhead dredging operations involve upland placement/disposal of the dredged material.
Therefore, the discharge end of the pipeline is connected to shore pipe. When effective
pumping distances to the placement/disposal site become too long, a booster pump is added
to the pipeline to increase the efficiency of the dredging operation.

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[2525–Task 4–Appendix F] A-4 Avon Village, Dare County, North Carolina

FIGURE A-1. Cutterhead suction dredge schematic and representative close-up photographs.
(Video of cutterhead dredge: http://el.erdc.usace.army.mil/dots/doer/anima/cutterfront.avi;
http://el.erdc.usace.army.mil/dots/doer/anima/cutterside.avi)

A.2 Hopper Dredge—Sedimentation and Turbidity
Hopper dredges are self-propelled vessels that contain pumps, holds, and equipment to collect
material from the seafloor, temporarily store it onboard, then motor to a pumpout or release point
close to the shore. For beach nourishment, the dredge hooks up to a length of submerged pipeline
that runs to shore and reverses the onboard pumps to push material to the beach. Once the
material reaches the shore, the dredge and fill operation is essentially identical to the discharge
of material via cutterhead dredge. The act of dredging by hopper dredges is via suction intakes
at the ends of drag arms lowered to the seafloor and dragged along the bottom. Water jets liquefy
the sediments into slurry pumped into the “hopper” of the vessel. Typically, oceangoing hopper
dredges excavate two furrows along the vessel’s track removing 1-2 feet of substrate with each
pass. Protocols for environmental protection during hopper dredge operations are well
established under NMFS (1997; 2020). These protocols are designed to minimize the collection of
sea turtles and other threatened species that may be present. They include turtle deflector heads

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[2525–Task 4–Appendix F] A-5 Avon Village, Dare County, North Carolina

around the intakes, screens to separate out larger materials, and operational requirements to
minimize pumping when the drag arms are in the water column above the seafloor. The applicant
will require contractors to adhere to all dredging protocols specified under the South Atlantic
Regional Biological Opinion (NMFS 1997;2020).

During dredging operations, marine resources within the vicinity of offshore borrow areas can
be affected by turbidity and sediment plumes generated from filling and overflow of hopper
dredges depending on the characteristics and suspension time of the sediment being dredged.
The discharge of overflow associated with hopper dredges to achieve economic loading
releases sediment into the water column. Cutterhead dredge operations are confined to the
benthic environment and associated turbidity is more confined. Hopper dredge suction
dragheads hydraulically remove sediment from the sand bottom and discharge the material
into the storage hoppers on the dredge. The screened sandy material fills the hopper until an
economic load is achieved for transit and subsequent pumpout to the beach placement
location. As illustrated in Figure A2 the operation has two types of sedimentation and turbidity
sources: S1 from the overflow (which for most U.S. dredges now is through the bottom of the
hull) and S2 associated with suspension of sediment at the draghead (as shown in Figure 8 of
2013 source document). During filling of the hopper, any fine sediment (primarily silt, clays, and
fine-sands) are washed overboard through overflow ports (i.e., S1) either over the side of the
vessel or through weirs that release the slurry through the hull of the vessel. Such washing of
the dredged material is the predominant source of turbidity plumes and sedimentation
generated by the hopper dredge; however, the washing effect also makes the hopper load for
pumpout to the beach coarser. Some turbidity would be expected from the physical interaction
of the draghead with the bottom substrate (i.e., S2) during the dredging operation, however, it
would not be expected to be significant considering most of the disturbed sediments would be
confined to the suction field of the hopper dredge dragheads and would be dredged and
disposed into the hopper. Sediment discharged overboard from the hopper overflow moves
faster than would be anticipated from simple Gaussian models because of the settlement
velocity of component particles. That is because of high sediment concentration and discharge
rate of the overflowed material, factors that lead to the development of a density current that
moves through the water column in a dynamic phase of settlement, at least initially. Sediment
is stripped away as the dynamic plume moves through the water column forming a passive
plume that is advected and dispersed by ambient currents, with the particles settling according
to Gaussian models (MMS, 2004).

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2525–Task 4–Appendix F] A-6 Avon Village, Dare County, North Carolina

FIGURE A2. Hopper dredge sedimentation processes.
Source: MMS, 2004

Note: This figure shows two S1 sources at overflows from a screening operation, in almost all
U.S. dredges, the S1 source is through the bottom of the hull.

Hitchcock and Drucker (1996) summarized values for material lost through the overflow
process on a typical 4,500-ton hopper dredge operating in United Kingdom (U.K.) waters.
Results from the study indicate that during an average loading time of 290 minutes, 4,185 tons
of dry solids are retained as cargo, while 7,973 tons of dry solids are returned overboard from
overflow. Such high proportions of returned sediments are not expected for the Avon borrow areas
which contain similar sediments as the borrow areas used at Nags Head (CSE 2012) AND Buxton
in 2017-2018. Post-dredging surveys at Nags Head and Buxton showed nearly equal excavation
and placement volumes on the beach. This implies only minor losses of excavated material at
both sites. The large hopper dredge used at Buxton filled in a typical time of one hour, which is
much more rapid that the filling rate for the UK study. Sand-sized particles fall directly to the
seabed and are reduced to background levels over a distance of 200–500 m (656–1,640 ft.) and
smaller, silt-sized particles have a typical settling velocity of 0.1 to 1.0 mm/s and are reduced to
background values of 2–5 milligrams per liter (mg/L) over a similar distance. According to Neff
(1981, 1985), concentrations of 1,000 mg/L immediately after discharge decreased to 10 mg/L
within one hour. The minimal effect of settling particles from hopper dredge turbidity plumes
was further supported by a study from Poopetch (1982), which found that the initial hopper
dredge overflow concentrations of 3,500 mg/L were reduced to 500 mg/L within 50 m (164 ft.).

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[2525–Task 4–Appendix F] A-7 Avon Village, Dare County, North Carolina

The distance that sediment plumes can extend depends on the type of dredge, how it is
operated, currents, and the nature of the sediments in the dredged area. Only beach-
compatible, sandy sediments would be used for the Buxton and Avon projects consisting of no less
than 90% sand. Dredging of sandy sediments would minimize the amount of turbidity
associated with the dredging operation and would reduce the suspension time and advection
distance of overflow sediments. A study performed by Newell and Siederer (2003) in the U.K.
(high-current velocities) showed that, in most cases, coarse material up to sand-size particles
settles within 200 m (656 ft.) to 600 m (1,968 ft.) of the point source of discharge, depending on
depth of water, tidal velocity, and the velocity of flow from the discharge pipe. During hopper
dredging operations in the Baltic Sea, Gajewski and Uscinowicz (1993) noted that the main
deposition of sand from hopper dredge overflow was confined to distances within 150 m (492
ft.) on each side of the dredge. The study further supported that the initial sedimentation
associated with overflow material behaves like a density current where particles are held
together by cohesion during the initial phase of the sedimentation process and are mainly
confined to a zone of a few hundred meters from the discharge chutes. According to a plume
dispersion model developed by Whiteside et al. (1995) (based on field study measurements
obtained while hopper dredging in Hong Kong waters), the contours for sediment deposition
remain as a narrow band extending for approximately 100 m (328 ft.) on each side of the vessel,
consistent with that recorded by Gajewski and Uscinowicz (1993).

Though elevated turbidity levels could occur from hopper dredge overflow, the overflow
process occurs only during the physical dredging operation and the elevated turbidity values
are short term and confined. Because maximum load efficiency would be attained before
transit to the pumpout location, overflow of material would not be expected to occur once the
dredging process is complete. Once at the pumpout location, all turbid water generated by the
hopper dredge slurry for pumpout would be retained in the hopper.

Overall water quality impacts of the proposed action would be expected to be short-term and
minor. The various life stages of fish species associated with marine and estuarine resources
dependent on good water quality would likely move out of the impact area and are not
expected to experience significant adverse effects from water quality changes. Therefore, the
proposed action is not anticipated to adversely impact the marine water column either in the
offshore borrow areas and/or the ocean beach strand.

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TABLE 4. Anticipated species protection recommendations for dredge operations (after USACE 2013 and the 2020 SARBO PDCs) in addition t o regular NPS monitoring surveys. Other additional monitoring may be required as a result of NEPA process and/or
specific conditions attached to permits as a result of USACE risk assessments or consultations. The comment column has been modified to reflect the Avon Village beach nourishment project. Sea turtles and Atlantic sturgeon are primary species of concern.

Source Recommendation
Considered in Borrow
Area Design and Dredging Comments Updated for Avon Where Possible/Applicable (in bold)
Yes Partial No
Dibajnia and
Nairn (2011)
Avoid shoals in waters deeper than 30 meter
(m) which show a decrease in height with
increasing depth representing a possible Shoal
Height Decrease Zone beyond 30 m depth
X The shallowest portion of the proposed borrow areas proposed to be dredged (i.e., top of ridge) ranges
between 35–40 ft deep and the deepest areas along the gently sloping sides of the ridge ranges between 45 –
50 ft deep.
Consider ridge and shoal dredging scenarios
which minimize impacts to overall shoal
integrity and protect habitat for benthos and
fish
X
The proposed borrow area use plans would be developed in accordance with dredge guidelines to the maximum
extent practicable to minimize morphologic shoal response provided by Dibajnia and Nairn (2011). Cuts would be
targeted such that portions of the habitat structure unique to the feature and important to resource use would be
maintained; thus, no adverse effects to overall shoal integrity are expected. Geotechnical data (CSE 2021) confirm
there is uniformity of sediment size and type within the full section of the proposed dredge cut, with similar
quality surficial sediments expected to be left in place after excavations of overlying material.
CSA
International
Inc et al. (2009)
Priority locations for shoal dredging to
minimize physical impacts is the leading edge
due to net long-term deposition and faster
infilling rates, followed by the crest and the
trailing edge
X
Use of the topographic high within the proposed borrow areas, overall shallow excavation depth of the cutterhead
or hopper dredge, and the borrow site’s location in an area of high sand movement are important factors that would
maximize biological recovery rates. However, once the proposed borrow area surveys have been completed,
coordination with appropriate State and Federal Agencies would occur to avoid impacts to existing high valued
biological resources associated with specific shoal features.
Innovative dredging methodologies utilizing
“striped” dredging pattern appear to support a
more timely and uniform recovery
X Hopper dredges are the proposed primary dredge method. Hopper dredge operations typically dredge in a "striped"
pattern to maximize production over long expansive portions of the borrow areas leaving portions of the borrow
areas unimpacted.
Shallow dredging over large areas rather than
excavating small but deep pits may be
preferred
X The current borrow area design and borrow area use plan supports this recommendation. Hopper dredges operate
most efficiently dredging shallow cuts over a large surface area rather than excavation of small deep pits. The usable
dredge depths would be determined once the surveys have been completed.
Dredging in a striped pattern to leave sediment
sources adjacent to and interspersed
throughout target areas, leading to a more
uniformly distributed infilling process
X Hopper dredge operations typically dredge in a "striped" pattern to maximize production over long expansive portions
of the borrow areas leaving portions of the borrow areas unimpacted to support infill processes.
Discussions
with NMFS
and NCDMF
Borrow area design should consider a wider
and shallower cuts rather than deep dredge
holes
X
Geotechnical data (CSE 2021) within the proposed borrow areas confirm the sediments are beach compatible and
exceed North Carolina state standards for similarity with the native beach. A high density of 15 borings (~1 per 20
acres) demonstrates general uniformity of sediments in the upper 10 ft of substrate in Borrow Area 1 and 6 ft in
Borrow Area 2. The potential beach quality sand reserves total ~3.4 million cubic yards within an ~250-acre area if
the proposed dredging depths are permitted. Shallower cuts over a smaller area are therefore feasible. The final
borrow area layout and dredge plan would be prepared in consultation with resource agencies pending results of
cultural resource studies. If a suction cutterhead dredge is used, the minimum and maximum excavation depth
would be in the range 6–10 ft due to operational considerations for large ocean-certified dredges. If a hopper dredge
is used, the cut depths would vary between ~2 ft and 10 ft according to the number of passes over a given area.

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2525–Task 4–Appendix F] A-10 Avon Village, Dare County, North Carolina

Table 4 (continued).

Source Recommendation
Considered in Borrow Area
Design and Dredging Comments
Yes Partial No
Discussions
with NMFS
and NCDMF
(cont’d)
Review published literature and integrate significant
information or lessons learned from dredging of other
shoal features throughout the region into borrow area use
planning for this project
X Relevant literature as it pertains to the physical and biological activities associated with sand ridge
features as well as potential dredge-related impacts have been integrated into this impact
evaluation.
Consider leaving a segment of un-dredged sediment to
allow for recovery and recolonization into impacted
areas.
X
Hopper dredges would likely be the primary dredge methodology for this project. As a result of the
operation characteristics of the hopper dredge, it is likely that un-dredged ridges would be left
behind for recolonization from un-impacted areas. Additionally, it is anticipated that the dynamic
nature of the borrow areas would result in infill of the impacted areas with adjacent sediments.
Diaz et al.
(2004) and
Slacum et al.
(2010)
Shoals should be only partially dredged to facilitate post
dredging re-colonization from un-impacted refuge areas X The proposed borrow areas and associated quantity of sediment to be dredged is small relative to
the areas of shoals off Hatteras Island, including Platt, Wimble, Kinnakeet, and Diamond Shoals.
Limiting the distance between the remaining patches of
shoal habitat would reduce the distance and time a shoal-
associating species would have to travel between patches
X
The proposed borrow areas are located at an un-named sand ridge and is approximately 1.5
miles southeast of Kinnakeet Shoal. It is a rather small component within the overall complex
of available habitat. Considering the nearness of similar adjacent habitat types no adverse
impacts to shoal associated species are anticipated.
Shoals with less relief should be targeted for mining
instead of steeper shoals when the option is available X The borrow area use plan would be developed that maximizes opportunity to dredge along the
relatively flat and gradual sloped transition towards the shoal crest in order to minimize shoal
impacts to higher relief shoal features.
Dredging should be avoided when demersal finfish are
using the inner continental shelf as a nursery ground X
Dredging for the proposed Avon Village beach nourishment is proposed to occur in summer
2022 and is anticipated to be completed in two to three months (anticipated to begin between
May and July).
Sand could be mined at night, when some species migrate
vertically into the water column to reduce the direct injury
to fish that can result from mining activities
X Dredge activities would not be confined to nighttime activities due to efficiency constraints.
Shoals should be mined in rotation to allow shoal-
associated assemblages to recover between mining
events; this should be done in consideration of the rate at
which sand accumulates at the particular shoal where
sand is being harvested
X The proposed Avon Village nourishment project is a one-time only event. Benthic communities
of the borrow areas are expected to quickly recover.

CZR Inc. and Coastal Science & Engineering EFH Assessment – July 2021
[2525–Task 4–Appendix F] A-11 Avon Village, Dare County, North Carolina

REFERENCES FOR ATTACHMENT A NOT CITED PREVIOUSLY

Gajewski, L.S., and S. Uscinowicz. 1993. Hydrologic and sedimentologic aspects of mining
marine aggregate from the Slupsk Bank (Baltic Sea). Marine Georesources and Geotechnology
11:229–244.

Hitchcock, D.R., and B.R. Drucker. 1996. Investigation of benthic and surface plumes associated
with marine aggregates mining in the UK. In Conference Proceedings Oceanology International
’96. Volume 2. ISBN: 0 90025412 2. pp. 220-234.

NMFS. 1997. Regional biological opinion concerning the use of hopper dredges in channels and
borrow areas along the southeast U.S. Atlantic coast. South Atlantic Regional Biological
Opinion (SARBO). National Marine Fisheries Service, Silver Spring, MD, 16 pp.

Newell, R.C. and L.J. Seiderer. 2003. Ecological Impacts of Marine Aggregate Dredging on
Seabed Resources. In Review of Existing and Emerging Environmentally Friendly Offshore
Dredging Technologies. Prepared for the U.S. Department of Interior, Leasing Division, Sand and
Gravel Unit Minerals Management Service, Herndon, VA.

U.S. Department of Interior, Minerals Management Service (MMS). 2004. Review of Existing and
Emerging Environmentally Friendly Offshore Dredging Technologies. Prepared by W.F. Baird
and Associates, Ltd. and research Planning, Inc. for the MMS Leasing Division, Sand and Gravel
Unit.

Whiteside, P.G.D., K. Ooms, and G.M. Postma. 1995. Generation and decay of sediment plumes
from sand dredging overflow. In Proceedings of the 14th World Dredging Conference Amsterdam,
The Netherlands. pp. 877–892.