20081706 Ver 1_Other Agency Comments_20071117

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<~ENT Op
r United States Department of the Interior
FISH AND WILDLIFE SERVICE
Raleigh Field Office
y4ACH Post Office Box 33726
Raleigh, North Carolina 27636-3726
November 14, 2007

John F. Sullivan III, PE
Federal Highway Administration
310 New Bern Avenue, Suite 410
Raleigh, North Carolina 27601

Dear Mr. Sullivan:

This document transmits the U.S. Fish and Wildlife Service's (Service) biological opinion (BO)
based on our review of the proposed replacement of Bridge No. 4 over Shocco Creek on US 401
located in Warren County, North Carolina (TIP No. B-4307), and its effects on the federally
endangered dwarf wedgemussel (Alasmidonta heterodon, DWM) in accordance with section 7 of
the Endangered Species Act (ESA) of 1973, as amended (16 U.S.C. 1531-1543). Your
November 7, 2007 request for formal consultation was received on November 9, 2007.

This BO is based on information provided in the September 27, 2007 Biological Assessment
(BA) prepared by the North Carolina Department of Transportation (NCDOT), telephone
conversations, emails, field investigations and other sources of information. A complete
administrative record of this consultation is on file at this office.

The BA also addressed the effects of the project on the federally endangered Tar River
spinymussel (Elliptio steinstansana). The NCDOT has determined that the project may effect,
but is not likely to adversely affect the Tar River spinymussel. Based on available information,
the Service concurs with the determination that the project may affect, but is not likely to
adversely affect the Tar River spinymussel. This species will not be addressed in the following
BO.

CONSULTATION HISTORY

July 16, 2003 - The Service provides comments in response to a scoping request, that we have
concerns that federally listed mussels may be affected by the project.

March 29, 2006 - Service staff field inspected project site.

April 12, 2006 - NCDOT holds hydraulic design meeting where project design and conservation
measures to avoid/mimmize effects to the DWM are discussed with the Service and the North
Carolina Wildlife Resources Commission. A decision is made that the project would require
formal section 7 consultation.
t

Apri126, 2006 - Service staff and NCDOT Natural Environment Unit (NEU) staff have
discussions regarding development of BA and further avoidance and minimization measures.

July 10, 2006 - Service staff and NCDOT NEU have additional discussions regarding need for
updated survey work.

April 4, 2007 - NCDOT biologists perform mussel survey and observe one DWM near the
project site.

April 9, 2007 - Service staff and NCDOT NEU staff continue discussions regarding
conservation measures.

April 23, 2007 - Service staff and NCDOT biologists conduct another mussel survey at project
site, without observing DWM.

July 3, 2007 - NCDOT biologists perform another mussel survey and observe a single DWM at
the same location as the April 4, 2007 occurrence.

July 11, 2007 - Service staff and NCDOT NEU staff continue discussions regarding
conservation measures.

November 9, 2007 - The Service received a letter from the Federal Highway Administration
(FHWA), dated November 7, 2007, with the attached final BA, requesting formal consultation
on the proposed Bridge No. 4 replacement over Shocco Creek.

BIOLOGICAL OPINION

1. DESCRIPTION OF THE PROPOSED ACTION

The B-4307 project is located at the US 401 crossing of Shocco Creek in Warren County, North
Carolina, approximately 2.5 miles north of the Franklin/Warren County line. The existing four-
span, 71 feet long bridge will be replaced with a single-span, 135 feet long steel-plate girder
bridge. The new bridge will be placed in the same horizontal alignment, but the elevation of the
structure will be raised. The new bridge will completely span the channel of Shocco Creek and
some existing causeway will be removed from the flood plain. Approach road work will consist
of raising the grade by placing fill, resurfacing and tying into existing alignment for
approximately 480 feet on the north and 610 feet on the south approach. Traffic will be detoured
onto other roads during construction. The project is currently scheduled to be let on February 17,
2009.

Action Area

The action area is defined as the US 401 project right-of-way (ROW) of B-4307, beginning
approximately 480 feet north of the bridge to approximately 610 feet south of the bridge, plus
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Shocco Creek for a distance 400 meters downstream and 100 meters upstream of the bridge. The
action area consists mainly of a maintained/disturbed roadside vegetative community, the US
401 pavement and bridge structure, the Shocco Creek channel and a portion of its beaver-
impounded flood plain. The action area occurs in Tar River Sub-basin 03-03-04, as assigned by
the North Carolina Department of Environment and Natural Resources, Division of Water
Quality Section. Within the action area, Shocco Creek is impounded by at least two beaver dams
approximately 200 meters and 300 meters downstream of the bridge crossing. During high water
events, flow has been diverted onto the flood plain of the right descending bank. This diversion
has created a network of braided channels that are eroding the soil of the flood plain. Much of
the eroded material has been deposited in the stream channel and most of the habitat is covered
by a thick layer of unconsolidated detritus. Most of the habitat within the action area is not
suitable for DWM. However, one small area approximately 30-40 meters downstream of the
bridge, consisting of approximately 40 square meters of clean sand and woody debris provides
suitable habitat for DWM.

Conservation Measures

Conservation measures represent actions, pledged in the project description, that the action
agency will implement to minimize the effects of the proposed action and further the recovery of
the species under review. Such measures should be closely related to the action and should be
achievable within the authority of the action agency. Since conservation measures are part of the
proposed action, their implementation is required under the terms of the consultation. The
FHWA and NCDOT have proposed the following conservation measures.

• Design of a single span structure will eliminate bents in the stream and provide a larger
hydraulic cross section to reduce scouring downstream of the bridge. This design also allows
for the removal of some of the existing causeway, providing additional floodplain to the
stream. A single span structure will eliminate the need for a temporary work bridge.
• Deck drains will not be allowed to discharge directly into stream.
• Traffic will be maintained on an offsite detour.
• "Design Standards in Sensitive Watersheds" [15A NCAC 04B.0124 (b)-(e)] will apply.
• Best Management Practices for Bridge Demolition and Removal will be implemented during
the removal of the existing bridge.
• Existing bents will be cut at substrate level to minimize disturbance to the substrate.
• Existing abutments will be removed in stepwise fashion to reduce the potential for
sedimentation.
• The areas adjacent to Shocco Creek will be identified as "Environmentally Sensitive Areas"
on the Sedimentation and Erosion Control Plans for this project. By definition, the
Environmentally Sensitive Areas will be identified as a 50-foot buffer zone on both sides of
the stream measured from top of stream bank. Within the identified 50-foot Environmentally
Sensitive Areas, the following shall apply:
o In areas identified as Environmentally Sensitive Areas, the Contractor may perform
clearing operations, but not grubbing operations until immediately prior to beginning
grading operations.

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o Once grading operations begin in identified Environmentally Sensitive Areas, work
shall progress in a continuous manner until complete.
o In areas identified as Environmentally Sensitive Areas, erosion control devices shall
be installed immediately following the clearing operation.
o In areas identified as Environmentally Sensitive Areas, "Seeding and Mulching" shall
be performed on the areas disturbed by construction immediately following final
grade establishment.
o In areas identified as Environmentally Sensitive Areas, seeding and mulching shall be
done in stages on cut and fill slopes that are greater than 20 feet in height measured
along the slope, or greater than 2 acres in area, whichever is less.

II. STATUS OF THE SPECIES

The DWM was federally listed as endangered on March 14, 1990. The DWM is found solely in
Atlantic Coast drainage streams and rivers of various sizes and moderate current. It ranges from
New Hampshire to North Carolina, in small creeks to deep rivers in stable habitat with substrates
ranging from mixed sand, pebble and gravel, to clay and silty sand. In the southern portion of its
range, it is often found buried under logs or root mats in shallow water (USFWS 1993); whereas
in the northern portion of its range, it may be found in firm substrates of mixed sand, gravel or
cobble, or embedded in clay banks in water depths of a few inches to greater than 20 feet (Fichtel
and Smith 1995; Gabriel 1995; Gabriel 1996; Nedeau and Werle 2003; Nedeau 2004a, 2004b,
2006a).

The DWM's reproductive cycle is typical of other freshwater mussels, requiring a host fish on
which its larvae (glochidia) parasitize and metamorphose into juvenile mussels. The DWM is
not a long-lived species as compared to other freshwater mussels; life expectancy is estimated at
10 to 12 years (Michaelson and Neves 1995).

Human activity has significantly degraded DWM habitat causing a general decline in populations
and a reduction in distribution of the species. Primary factors responsible for the decline of the
DWM include: 1) impoundment of river systems, 2) pollution, 3) alteration of riverbanks, and 4)
siltation (USFWS 1993).

Damming and channelization of rivers throughout the DWM's range have resulted in the
elimination or alteration of much of its formerly occupied habitat (Wafters 2001). Domestic and
industrial pollution was the primary cause for mussel extirpation at many historic sites. Mussels
are known to be sensitive to a wide variety of heavy metals and pesticides, and to excessive
nutrients and chlorine (Havlik and Marking 1987). Mussel die-offs have been attributed to
chemical spills, agricultural waste run-off and low dissolved oxygen levels.

Because freshwater mussels are relatively sedentary and cannot move quickly or for long
distances, they cannot easily escape when silt is deposited over their habitat. Siltation has been
documented to be extremely detrimental to mussel populations by degrading substrate and water
quality, increasing exposure to other pollutants and by direct smothering of mussels (Ellis 1936,

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Markings and Bills 1979). In Massachusetts, a bridge construction project decimated a
population of DWM by accelerated sedimentation and erosion (Smith 1981).

Most DWM populations are small and geographically isolated from each. This isolation restricts
exchange of genetic material among populations and reduces genetic variability within
populations (USFWS 1993).

At one time, DWM was recorded from 70 localities in 15 major drainages ranging from North
Carolina to New Brunswick, Canada. Since the 1993 Recovery Plan, a number of new locations
have been discovered and a number of known locations are possibly no longer extant. Based on
preliminary information, the dwarf wedgemussel is currently found in 15 major drainages (Table
1), comprising approximately 70 "sites" (one site may have multiple occurrences). At least 45 of
these sites are based on less than five individuals or solely on spent shells (USFWS 2007).

Table 1. Dwarf wedgemussel major drainages.

State Major Drainage County
NH Upper Connecticut River Coos, Grafton, Sullivan, Cheshire
VT Upper Connecticut River Essex, Orange, Windsor, Windham
MA Middle Connecticut River Hampshire, Hampden
CT Lower Connecticut River Hartford
NY Middle Delaware Orange, Sullivan, Delaware
NJ Middle Delaware Warren, Sussex
PA Upper Delaware River Wayne

MD Choptank River Queen Anne's, Caroline
MD Lower Potomac River St. Mary's, Charles
MD Upper Chesapeake Bay Queen Anne's
VA Middle Potomac River Stafford
VA York River Louisa, Spotsylvania
VA Chowan River Sussex, Nottoway, Lunenburg
NC Upper Tar River Granville, Vance, Franklin, Nash
NC Fishing Creek Warren, Franklin, Halifax
NC Contentnea Wilson, Nash
NC Upper Neuse Johnson, Wake, Orange

* The 15 major drainages identified in Table 1 do not necessarily correspond to the original drainages identified in
the 1993 Recovery Plan although there is considerable overlap.

The main stem of the Connecticut River in New Hampshire and Vermont is considered to have
the largest remaining DWM population, consisting of three distinct stretches of sporadically
occupied habitat segmented by hydroelectric dams. It is estimated that there are hundreds of
thousands of DWM scattered within an approximate 75-mile stretch of the Connecticut River.
The Ashuelot River in New Hampshire, the Farmington River in Connecticut, and the Neversink
River in New York harbor large populations, but these number in the thousands only. The

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remaining populations from New Jersey south to North Carolina are estimated at a few
individuals to a few hundred individuals (USFWS 2007).

In summary, it appears that the populations in North Carolina, Virginia, and Maryland are
declining as evidenced by low densities, lack of reproduction, or inability to relocate any DWM
in follow-up surveys. Populations in New Hampshire, Massachusetts, and Connecticut appear to
be stable, while the status of populations in the Delaware River watershed affected by the recent
floods of 2005 is uncertain at this time (USFWS 2007).

III. ENVIRONMENTAL BASELINE

Under section 7(a)(2) of the Act, when considering the "effects of the action" on federally listed
species, the Service is required to take into consideration the environmental baseline. The
environmental baseline includes past and ongoing natural factors and the past and present
impacts of all federal, state, or private actions and other activities in the action area (50 CFR
402.02), including federal actions in the area that have already undergone section 7 consultation,
and the impacts of state or private actions which are contemporaneous with the consultation in
process.

Status of the Species Within the Action Area

Records maintained by the North Carolina Natural Heritage Program (NCNHP) show DWM to
be present in Shocco Creek at several locations along most of its length, and with recent
observations. Surveys conducted within the action area on July 28, 2005; April 4, 2007 and July
3, 2007 each revealed a single DWM. Most of the habitat within the action area can be defined
as unsuitable for DWM due to the presence of at least two beaver dams approximately 200
meters and 300 meters downstream. Most of the substrate is covered in a thick layer of
unconsolidated detritus. However, one small area approximately 30-40 meters downstream of
the bridge, consisting of approximately 40 square meters of clean sand and woody debris
provides suitable habitat for DWM. This is the location where DWM was observed in the April
4, 2007 and July 3, 2007 surveys. It appears that the species is still present within the action
area, but in very small numbers. It is unclear how long DWM can persist within the action area
due to downstream beaver activity.

Factors Affecting the Species Environment Within the Action Area

The existing bridge has associated causeways for the approach roads which encroach upon the
flood plain. This bottlenecking of the flood plain appears to have scoured the channel bottom
underneath and immediately downstream of the bridge down to a clay layer, thus eliminating all
habitat for DWM for approximately 30-40 meters.

The most prevalent current factor affecting the species in and near the action area is the effect of
the two downstream beaver dams previously described. As long as the beaver dams are present,
additional sediment and debris will continue to settle out on the substrate, thus further degrading
the minimal amount of suitable habitat remaining within the action area.
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IV. EFFECTS OF THE ACTION

Under section 7(a)(2) of the Act, "effects of the action" refers to the direct and indirect effects of
an action on the species or critical habitat, together with the effects of other activities that are
interrelated or interdependent with that action. The federal agency is responsible for analyzing
these effects. The effects of the proposed action are added to the environmental baseline to
determine the future baseline, which serves as the basis for the determination in this BO. Should
the effects of the federal action result in a situation that would jeopardize the continued existence
of the species, we may propose reasonable and prudent alternatives that the federal agency can
take to avoid a violation of section 7(a)(2). The discussion that follows is our evaluation of the
anticipated direct and indirect effects of the proposed project. Indirect effects are those caused
by the proposed action that occur later in time but are still reasonably certain to occur (50 CFR
402.02).

Factors to be Considered

The little remaining DWM habitat (approximately 40 square meters) within the action area is
degrading due to downstream beaver activity. This small area of suitable habitat is located
approximately 30-40 meters downstream of the bridge. As of July 3, 2007, at least one DWM
was still present within remaining suitable habitat. It is uncertain whether the species will still be
present by the time of project construction. If the species does occur within the action area, the
minimal amount of work within the channel is expected to have negative effects for only a short
duration.

Analysis for Effects of the Action

Beneficial Effects: The removal of the existing bridge bents in the channel and the commitment
to completely span the channel will have beneficial effects. Given that in-channel bents can trap
debris during high flows and can change stream hydraulics in the immediate vicinity of the
structure (causing scour and deposition), the elimination of the in-channel bents are expected to
reduce the bridge's effects on stream-flow patterns. Also, given that large debris piles must
often be removed from in-channel bents (creating additional channel disturbance and
downstream sedimentation), the elimination of the in-channel bent will thus preclude future
disturbance for debris removal. With the lengthening of the bridge from 71 feet to 135 feet, the
stream will be able to access more of its floodplain, thus potentially reducing downstream bank
scouring and sedimentation. Removal of some causeway fill will increase the waterway opening
from 525 square feet to approximately 1010 square feet.'

Direct Effects: The stream channel will be completely spanned, thus greatly minimizing the
potential for direct effects. Due to the lack of suitable habitat directly beneath the bridge, it is
unlikely that any DWM would be directly killed by bridge demolition. The existing bents within
the channel, which consist of wooden piles driven directly into the substrate without buried
footing, will be cut off flush with the substrate. Since these occur within the scoured clay
bottom, it is unlikely that any direct DWM mortality would occur from this activity. A small
amount of sediment could enter the water column and redeposit downstream, but the amount
would likely be sub-lethal to any DWM.
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Sedimentation from construction activities along the stream bank and approach road appears to
have the greatest potential to directly affect DWM. A major storm event could erode soil from
within the disturbed construction area and wash it into the stream, thus smothering mussels,
interfering with respiration and feeding, and degrading habitat. To avoid or minimize the
potential for this effect, NCDOT has developed stringent erosion control measures and other
conservation measures (see "Conservation Measures" section of this BO) which greatly reduce
the likelihood of sediment entering the stream.

Indirect Effects: Since the project involves replacing an existing two-lane bridge with a new
two-lane bridge, it is unlikely that the project will promote any secondary development or land-
use changes. Also, since no new bents will be placed in the channel, no negative indirect effects
to stream flow are anticipated. Overall, the project is not likely to have any measurable indirect
effect on DWM or its habitat.

Interrelated and Interdependent Actions: None known.

V. CUMMULATIVE EFFECTS

Cumulative effects include the effects of future state, tribal, local or private actions that are
reasonably certain to occur in the action area considered in this BO. Future federal actions that
are unrelated to the proposed action are not considered in this section because they require
separate consultation pursuant to section 7 of the ESA. At this time there are no known future
local, state or private actions, not requiring federal actions that are reasonably certain to occur
within the action area.

VI. CONCLUSION

After reviewing the current status of the DWM, the environmental baseline for the action area,
all effects of the proposed project, and the conservation measures identified in the BA, it is the
Service's biological opinion that the proposed replacement of Bridge No. 4 over Shocco Creek
on US 401 (TIP No. B-4307), as proposed, is not likely to jeopardize the continued existence of
this species. No critical habitat has been designated for this species; therefore, none will be
affected.

This non jeopardy opinion is based, in part, on the following facts: Due to degrading conditions
of suitable habitat from the effects of downstream beaver dams, and due to the small amount of
suitable habitat within the action area, it is uncertain that DWM will still exist within the action
area by the time of project construction. The project has significant long-term beneficial effects.
In-channel work will be minimal, thus limiting the potential for negative effects. Direct
mortality of DWM is unlikely. Several conservation measures will reduce the potential for
negative effects of construction activities along the stream bank.

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INCIDENTAL TAKE STATEMENT

Section 9 of the ESA and federal regulations pursuant to Section 4(d) of the ESA prohibit the
taking of endangered and threatened species, respectively, without special exemption. Take is
defined as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or attempt to
engage in any such conduct. Harm is further defined by the Service to include significant habitat
modification or degradation that results in death or injury to listed species by significantly
impairing essential behavioral patterns such as breeding, feeding or sheltering. Harass is defined
by the Service as intentional or negligent actions that create the likelihood of injury to listed
species to such an extent as to significantly disrupt normal behavior patterns which include, but
are not limited to, breeding, feeding or sheltering. Incidental take is defined as take that is
incidental to, and not the purpose of, the carrying out of an otherwise lawful activity. Under the
terms of Section 7(b)(4) and Section 7(0)(2), taking that is incidental to and not intended as part
of the agency action is not considered to be prohibited taking under the ESA provided that such
taking is in compliance with the terms and conditions of this Incidental Take Statement.

The measures described below are non-discretionary, and must be undertaken by the FHWA so
that they may become binding conditions of any grant or permit issued to the NCDOT, as
appropriate, for the exemption in section 7(0)(2) to apply. The FHWA has a continuing duty to
regulate the activity covered by this Incidental Take Statement. If the FHWA (1) fails to assume
and implement the terms and conditions or (2) fails to require the NCDOT to adhere to the terms
and conditions of the Incidental Take Statement through enforceable terms that are added to the
permit or grant document, the protective coverage of section 7(0)(2) may lapse. To monitor the
impact of incidental take, the FHWA or the NCDOT must report the progress of the action and
its impact on the species to the Service as specified in the Incidental Take Statement [50 CFR
§402.14(I)(3)].

Amount or Extent of Take Anticipated

The Service anticipates that incidental take of the DWM may occur as a result of the bridge
replacement. During demolition of the existing bridge and construction of the new bridge,
DWM may be harmed by siltation or other water quality degradation. The effects are likely to be
sub-lethal.

Because there are no reliable data on the number of DWM buried in the substrate compared to
those on the surface (and even those on the surface are difficult to detect), it is not possible to
base the amount of incidental take on numbers of individual mussels. Additionally, incidental
take will likely be difficult to detect and monitor. Although spent shells may be collected,
attributing the cause of mortality may be difficult. Glochidia and juvenile mussels are also
extremely difficult to sample, therefore it is difficult to document take of either of these life
stages.

The level of incidental take of the DWM can be defined as all DWM that may be harmed,
harassed, or killed within the action area (400 meters downstream and 100 meters upstream of
the existing bridge). The number of individuals is expected to be very small. If incidental take is
exceeded, all work should stop, and the Service should be contacted immediately.
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Effect of the Take

In the accompanying BO, the Service has determined that the level of anticipated take is not
likely to result in jeopardy to the DWM. Since critical habitat has not been designated for this
species, the proposed project will not result in the destruction or adverse modification of critical
habitat.

Reasonable and Prudent Measures

The Service believes the following reasonable and prudent measures are necessary and
appropriate to minimize take of the DWM. These nondiscretionary measures include, but are not
limited to, the terms and conditions outlined in this BO.

1. All Conservation Measures previously described in this BO must be implemented.

2. NCDOT will ensure that the contractor understands and follows the measures listed in the
"Conservation Measures" section of this BO.

Terms and Conditions

In order to be exempt from the prohibitions of section 9 of the ESA, the NCDOT must comply
with the following terms and conditions, which implement the reasonable and prudent measures
described previously and outline required reporting requirements. These terms and conditions are
nondiscretionary.

1. A Service biologist will be invited to the preconstruction meeting to discuss any questions
the contractor has regarding implementation of these projects.

2. NCDOT will ensure that a Division Environmental Officer maintains a level of oversight to
insure that all appropriate erosion control measures are fully implemented to avoid/minimize
sedimentation of the stream.

CONSERVATION RECOMMENDATIONS

Section 7(a)(1) of the Act directs federal agencies to use their authorities to further the purposes
of the ESA by carrying out conservation programs for the benefit of endangered and threatened
species. The following conservation recommendations are discretionary agency activities to
minimize or avoid adverse effects of a proposed action on listed species or critical habitat, to
help implement recovery plans, or to develop information.

1. Acquire riparian conservation buffers in the Tar-Pamlico Subbasin 03-03-04 to benefit DWM
either individually or in concert with other conservation programs.

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2. Conduct periodic DWM status surveys in the Upper Tar Basin and submit results to the
Service.

3. Contribute funding and/or staff to any future DWM reintroduction or population
augmentation efforts conducted by others.

In order for the Service to be kept informed of actions minimizing or avoiding adverse effects or
benefiting listed species or their habitats, we request notification of the implementation of any
conservation recommendations.

REINITIATION/CLOSING STATEMENT

This concludes formal consultation on the action outlined in your November 7, 2007 request for
formal consultation. As provided in 50 CFR section 402.16, reinitiation of formal consultation is
required where discretionary federal agency involvement or control over the action has been
retained (or is authorized by law) and if. (1) new information reveals effects of the agency action
that may affect listed species or critical habitat in a manner or to an extent not considered in this
opinion; (2) the agency action is subsequently modified in a manner that causes an effect to the
listed species or critical habitat not considered in this opinion; or (3) a new species is listed or
critical habitat designated that may be affected by the action.

If you have any questions concerning this biological opinion, please contact Mr. Gary Jordan at
[phone] (Ext. 32).

S'ncere,

e e e in
Field ervisor

cc: Ken Graham, USFWS, Atlanta, GA
Susi von Oettingen, USFWS, Concord, NH
Eric Alsmeyer, USACE, Raleigh, NC
Greg Thorpe, NCDOT, Raleigh, NC
Logan Williams, NCDOT, Raleigh, NC
Chris Murray, NCDOT, Durham, NC
David Harris, NCDOT, Raleigh, NC
Chris Militscher, USEPA, Raleigh, NC
Travis Wilson, NCWRC, Creedmoor, NC
Rob Ridings, NCDWQ, Raleigh, NC

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Literature Cited
Ellis, M. M. 1936. Erosion silt as a factor in aquatic environments. Ecology 17:29-42.

Fichtel, C. and D. G. Smith. 1995. The Freshwater Mussels of Vermont. Nongame and Natural
Heritage Program, Vermont Fish and Wildlife Department. Technical Report 18. 53 pp.

Gabriel, M. 1995. Freshwater mussel distribution in the rivers and streams of Cheshire,
Hillsborough, Merrimack and Rockingham Counties, New Hampshire. Report submitted
to U.S. Fish and Wildlife Service, New England Field Office and New Hampshire Fish
and Game Department. 60 pp.

Gabriel, M. 1996. 1996 Monitoring of the dwarf wedgemussel (Alasmidonta heterodon) in the
Ashuelot and Connecticut Rivers, New Hampshire. Report submitted to The Nature
Conservancy, Eastern Regional Office, Boston, Massachusetts. 27 pp.

Havlik, M. E. and L.L. Marking. 1987. Effects of contaminants on Naiad Mollusks
(Unionidae): A Review. U.S. Department of the Interior, Fish and Wildlife Service,
Resource Publication 164. Washington, D.C. 20 pp.

Marking, L.L. and T.D. Bills. 1979. Acute effects of silt and sand sedimentation on freshwater
mussels. Pages 204-211 in: J.R. Rasmussen, ed. Proceedings of the UMRCC
symposium on Upper Mississippi River bivalve mollusks. Upper Mississippi River
Conservation Committee, Rock Island, Illinois.

Michaelson, D. L. and R. J. Neves. 1995. Life History and habitat of the endangered dwarf
wedgemussel Alasmidonta heterodon (Bivalvia:Unionidae). Jour. N. Am. Benthol. Soc.
14:324-340.

Nedeau, E. J. and S. Werle. 2003. Freshwater Mussels of the Ashuelot River: Keene to
Hinsdale. Unpublished report submitted to the U.S. Fish and Wildlife Service, Concord,
New Hampshire. 50 pp.

Nedeau, E. J. 2004a. A Fourth Investigation of the Survival of Dwarf Wedgemussels
(Alasmidonta heterodon) for the Relocation Project on the Connecticut River, Route 2
Stabilization Project, Lunenburg, Vermont. Unpublished report submitted to the U.S.
Fish and Wildlife Service, Concord, New Hampshire. 7 pp.

Nedeau, E. J. 2004b. Quantitative survey of dwarf wedgemussel (Alasmidonta heterodon)
populations downstream of the Surry Mountain Flood Control Dam on the Ashuelot
River. Unpublished report submitted to the U.S. Fish and Wildlife Service, Concord,
New Hampshire. 12 pp.

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Nedeau, E. 2006. Characterizing the Range and Habitat of Dwarf Wedgemussels in the "Middle
Macrosite" of the Upper Connecticut River. Unpublished report submitted to the U.S.
Fish and Wildlife Service, Concord, New Hampshire. 6 pp.

Smith, D. G. 1981. Selected freshwater invertebrates proposed for special concern status in
Massachusetts. Massachusetts Department of Environmental Quality Engineering.
Division of Water Pollution Control. Westborough, MA.

U.S. Fish and Wildlife Service. 1993. Dwarf Wedge Mussel Alasmidonta heterodon Recovery
Plan. Hadley, Massachusetts. 52 pp.

U.S. Fish and Wildlife Service. 2007. Dwarf Wedgemussel Alasmidonta heterodon 5-Year
Review: Summary and Evaluation. Concord, New Hampshire. 19 pp.

Watters, T. 2001. Freshwater mussels and water quality: A review of the effects of hydrologic
and instream habitat alterations. Proceedings of the First Freshwater Mollusk
Conservation Society Symposium, 1999. Ohio Biological Survey, Columbus, Ohio.
pages 261-274.

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