20081601 Ver 1_Other Agency Comments_20080904

United States Department of the Interior
FISH AND WILDLIFE SERVICE
Raleigh Field Office
Post Office Box 33726
Raleigh, North Carolina 27636-3726
September 4, 2008
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 based
on our review of the proposed replacement of Bridge No 193 over Shelton Creek on SR 1309,
located in Granville County, North Carolina (TIP No B-4524), and its effects on the federally
endangered dwarf wedgemussel (Alasmcdonta heterodon, DWM) in accordance with section 7 of
the Endangered Species Act (ESA) of 1973, as amended (16 U S C 1531-1543) Your August
25, 2008 request for formal consultation was received on August 26, 2008
If you have any questions concerning this biologic
[phone] (Ext 32) /
please contact Mr Gary Jordan at
f
Pete Be in
Field S 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 Hams, NCDOT, Raleigh, NC
Chris Militscher, USEPA, Raleigh, NC
Travis Wilson, NCWRC, Creedmoor, NC
Rob Ridings, NCDWQ, Raleigh, NC
1
This Biological Opinion (BO) is based on information provided in the 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
CONSULTATION HISTORY
July 24, 2006 - Service staff assisted in NCDOT mussel survey at project site
September 15, 2006 - NCDOT requested concurrence with a biological determination of "may
affect, not likely to adversely affect' 'for DWM
October 3, 2006 - The Service provided a letter to NCDOT stating that the Service does not
concur with the biological determination of "may affect, not likely to adversely affect" for
DWM
May-June 2007 - Service staff and NCDOT staff had discussions and email exchanges regarding
necessary conservation measures for the project
June 6, 2007 - Service staff and NCDOT Natural Environment Unit (NEU) staff met at the
project site
June 7, 2007 - The Service recommended that the Federal Highway Administration (FHWA)
initiate formal consultation for the project
January-February 2008 - Service staff and NCDOT staff had discussions and email exchanges
regarding the development of a BA _
February 25, 2008 - Service staff assisted in NCDOT mussel survey at project site
August 26, 2008 - The Service received a letter from the FHWA, dated August 25, 2008, with
the attached BA, requesting formal consultation on the proposed Bridge No 193 replacement
over Shelton Creek
BIOLOGICAL OPINION
1. DESCRIPTION OF THE PROPOSED ACTION
The B-4524 project is located at the SR 1309 crossing of Shelton Creek in Granville County,
North Carolina, approximately nine miles northwest of the city of Oxford The existing four-
span, 62 feet long bridge will be replaced with a single-span, 100 feet long box-beam bridge
The new bridge will be placed on the same alignment, but will be raised slightly The new
bridge will completely span the channel of Shelton Creek A total of 540 cubic yards of existing
fill will be removed from the floodplain at the bridge approaches and abutments The newly
shaped bank slopes will be stabilized with riprap above the waterline For equipment access, a
temporary access path will be constructed on both banks on the downstream side of the existing
bridge Riprap or timber matting will be used to stabilize the temporary paths The existing
bents will be removed from the channel Removal of the center bent will require a temporary
nprap causeway The existing approach roads will be widened from 18 feet to 20 feet for a
distance of approximately 280 feet to the south and 290 feet to the north. Traffic will be
detoured onto other roads during construction
Action Area
The action area is defined as the SR 1309 project right-of-way (ROW) of B-4524, beginning
approximately 280 feet south of the bridge to approximately 290 feet north of the bridge, plus
Shelton Creek for a distance of 1,312 feet (400 meters) downstream and 98 feet (30 meters)
upstream of the bridge The action area consists mainly of a maintamed/disturbed roadside
vegetative community, the SR 1309 pavement and bridge structure, and the Shelton Creek
channel. The action area occurs in Tar River Sub-basin 03-03-01, as assigned by the North
Carolina Department of Environment and Natural Resources, Division of Water Quality Section
At the project site, Shelton Creek is approximately 45 feet wide Bottomland hardwood forest
borders along each bank within the action area
[ r
Conservation, Measures w
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
• In areas identified as Environmentally Sensitive Areas, the contractor may perform clearing
operations, but not grubbing operations until immediately prior to beginning grading
operations
• Once grading operations begin in identified Environmentally Sensitive Areas, work shall
progress in a continuous manner until complete
• In areas identified as Environmentally Sensitive Areas, erosion control devices shall be
installed immediately following the clearing operation
• In areas identified as Environmentally Sensitive Areas, seeding and mulching shall be
performed on the areas disturbed by construction immediately following final grade
establishment
• 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 two acres in area, whichever is less
• An off-site detour will be utilized for this project
• NCDOT Best Management Practices for Bridge Demolition and Removal will be
implemented during the removal of the existing bridge
• No new bents will be placed in the channel New bents will be greater than 10 feet from the
normal waterline
• Deck drains will not be allowed to discharge directly into the stream
• Removal of the existing bents will take place when water flow level is at a mmimuin point
allowable within the project schedule and will be done in such a manner to minimize
disturbance to the stream bed
• Special sediment control fence will be installed along the top of the steam bank Standard
silt fence will be installed along the toe of slope parallel to the stream Once the disturbed
areas of the project draining to the special sediment control fence have been stabilized, the
special sediment control fence and all built up sediment adjacent to the fence will be
removed to natural ground and stabilized with a native grass mix
• All sedimentation and erosion control measures, throughout the project limits, will be
cleaned out when %2 full with sediment, to ensure proper function of the measures
• Rip rap slope protection will be installed simultaneously with the embankment construction
• A temporary access road for conveying construction equipment in the floodplain/buffer will
be stabilized with rock or timber matting A rock work pad or timber matting will also be
utilized between the stream bank and the interior bent in the stream for removal of the
interior bents
• Embankment construction and grading shall be managed in such a manner to prevent surface'
runoff/drainage from discharging into the riparian buffer All interim surfaces will be graded
to drain to temporary erosion control devices Temporary berms, ditches, etc will be
incorporated as necessary to prevent temporary runoff from discharging into the riparian
buffer (as specified in the NCDOT BMP manual)
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 burred 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 (Fichte]
and Smith 1995, Gabriel 1995, Gabriel 1996, Nedeau and Werle 2003, Nedeau 2004x, 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 (Watters 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,
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, Spotsylvama
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 mayor drainages identified in Table I do not necessarily correspond to the original drainages identified in
the 1993 Recovery Plan although these 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 Neversmk
River in New York harbor large populations, but these number in the thousands only The
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 m 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
The action area occurs within the Upper Tar River Basin Records maintained by the North
Carolina Natural Heritage Program (NCNHP) have shown DWM to be present in the Tar River
main stem between SR 1150 (Gooches Mill Road) and US 158 and in the following tnbutaries
Cub Creek, Shelton Creek, Fox Creek and North Fork Tar River All of the element occurrences
in the Upper Tar River Basin are designated as NHP Element Occurrence No 89, representing
them as a single population of DWM
Observations (G Jordan, Service, personal observations) of the Upper Tar River Basin suggest
that the DWM in the Upper Tar River Basin are genetically isolated and may not be represented
as a single population Shelton Creek and Fox Creek are a contiguous unit, separated from the
Tar River main stem by Gooches Mill Dam The dam is located at the mouth of Shelton Creek
and impounds the Tar River and Shelton Creek The habitat at their junction is not suitable for
DWM or their host species and likely represents a complete barrier to movement between the
two areas
Surveys conducted within the action area on July 24, 2006 and February 25, 2008 did not reveal
any live DWM However, a single dead DWM shell was found during a habitat assessment
within the action area in May 2006 NCNHP data also indicate a 2005 observation of DWM
approximately 2 8 miles downstream of the action area near the SR 1304 crossing Though no
live DWM have been found within the action area, the habitat is suitable and the presence of
DWM cannot be ruled out
On July 17, 2007, Shelton Creek was observed to have completely stopped flowing and was
reduced to a series of stagnant pools due to drought conditions (G Jordan, Service, personal
observation) Little or no rain occurred from July 2007 to at least November 2007 An October
29, 2007 site visit by NCDOT biologists to a location several miles downstream of the action
area near the confluence of Shelton Creek and Tar River revealed dry conditions and heavy
mussel mortality
Rainfall returned to the action area during the winter of 2007/2008 and flow resumed in Shelton
Creek A February 25, 2008 mussel survey conducted by Service and NCDOT staff several
miles downstream of the action area at the US 158 crossing of Shelton Creek revealed the
presence of at least small numbers of live DWM, demonstrating that some DWM survived the
drought conditions by burrowing down into moist subterranean substrate
Factors Affecting the Species Environment Within the Action Area
The existing bridge, with its approach fill material within the floodplain, may have affected
DWM habitat within the action area DWM, like all mussels, are sensitive to changes within
their watershed, particularly deforestation, urbanization and major construction activities
Presently the action area and surrounding areas are primarily rural and do not appear to be
experiencing deforestation, urbanization or any other major construction activities The most
prevalent recent factor affecting the species in and near the action area was the effect of the
severe 2007 drought and the lack of genetic connectivity with nearby, but isolated populations
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 pioject Indirect effects are those caused
by the proposed action that occur later in time but are still reasonably certain to occur (50 CFR
40202)
Factors to be Considered
Based on previous survey results, and given the effects of the severe 2007 draught, it is uncertain
that any DWM occur within the action area If the species does occur within the action area, the
project is expected to have negative effects for only a short duration The long term and overall
effect of the project may be beneficial if there is significant recovery of the species in the Upper
Tar Basin
Analysis for Effects of the Action
Beneficial Effects The commitment to completely span the channel and lengthen the bridge
from 62 feet to 100 feet will have beneficial effects Some of the approach fill material in the
floodplain at the existing abutments will be removed, allowing the stream to access more of its
floodplain This can be expected to reduce the bridge's effects on stream-flow patterns by
potentially reducing downstream bank scouring and sedimentation
Direct Effects A temporary causeway (rock work pad or timber matting) will be constructed
from one bank to the interior in-channel bent for its removal Placement of the causeway could
crush any DWM within its footprint If a high water event occurs during the time the causeway
is in place, the constricted flow could cause erosion of the opposite bank A causeway also adds
additional area for storm debris to collect on, further increasing the possibility of erosion
Material eroded from the stream bank could be deposited downstream onto DWM and/or their
habitat, possibly killing them or hampering respiration, feeding or reproduction The causeway
could be dislodged during a storm event, scattering debris downstream possibly onto DWM
and/or their habitat However, the temporary causeway is expected to only be in place for less
than a month, thus reducing the chance of effects The causeway may cause temporary
compaction of the underlying substrate after its removal
Removal of the in-channel bents may disturb sediment which will redeposit downstream,
potentially on DWM or within DWM habitat However, the small amount of sedimentation is
likely sub-lethal Of greater concern is prolonged erosion of the disturbed area on and along the
banks of the creek within the action area during the construction of the bridge and approach road
A mayor storm event could erode soil from within the disturbed construction area and wash it
into the stream, thus smothering mussels, interfering with respiration, feeding, and reproduction,
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 bents will be placed in the channel, no measurable 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
aie 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 193 over Shelton
Creek on SR 1309 (TIP No B-4524), 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 It is not known if DWM ;
exist within the action area The project has some beneficial effects Several conservation
measures will greatly reduce the potential for negative effects Any adverse effects are expected
to be short in duration
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(o)(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
9
The measures described below are non-discretionary, and must be undertaken by the FHWA 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, 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 [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,
individual mussels may be crushed, harmed by siltation or other water quality degradation, or
dislocated because of physical changes in their habitat
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 maybe 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 30 meters upstream of the
existing bridge) If incidental take is exceeded, all work should stop, and the Service should be
contacted immediately
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
10
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 These terms and conditions are nondiscretionary
1 NCDOT will ensure that the contractor understands and follows the measures listed in the
"Conservation Measures" section of this BO
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/mmimize 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 ' .
I Acquire riparian conservation buffers in the Upper Tar River Basin to benefit DWM
either unilaterally or in concert with other conservation programs
2 Conduct periodic DWM status surveys in the Upper Tar River 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
4 Contribute funding and/or staff to any future dam removal initiatives in the Upper Tar
River Basin
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 August 25, 2008 request for
formal consultation As provided in 50 CFR section 402 16, remrtiation 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
11
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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
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 (Alasmadonta 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 Alasmadonta 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
(Alasmadonta 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 (Alasmadonta 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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