Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
The many watersheds that comprise the drainage of the Winnipesaukee River were
recently surveyed by the New Hampshire Fish and Game Department. These surveys
were part of a statewide effort to quantify the presence of self-sustaining brook trout
(Salvelinus fontinalis) populations and to gather some preliminary information on their
habitat. These surveys also provide some information on the region’s general fish
community. An assessment to determine the status of brook trout within this region of
New Hampshire is of particular interest to the overall goal of protection because
information regarding this watershed does not currently exist. Current information
indicates brook trout populations are abundant and secure to the north of the
Winnipesauke River watershed, while impacts to habitats and localized extirpations
appear to have reduced populations to the south of this region. As this region continues
to grow, more pressure is placed on the ability to sustain water quality and habitat for
wild brook trout populations.
Background
Brook trout are the only native stream dwelling trout species in New Hampshire, having a
historic range that extended from Georgia to eastern Canada. It is believed that wild
brook trout were once present throughout all watersheds in New Hampshire. Increased
stream temperatures, changes to water chemistry, habitat fragmentation, increased rates
of predation and competition, loss of spawning locations, and the loss of stream habitat
complexity have led to reduced and isolated populations of wild brook trout both in New
Hampshire and throughout the species’ native range in the eastern portions of the United
States.
Recognizing the reduction in the distribution of wild brook trout, the Eastern Brook Trout
Joint Venture (easternbrooktrout.org/) was established. This public and private
partnership of state fish and wildlife agencies, federal natural resource agencies,
academic institutions, and local conservation organizations is working to protect existing
wild brook trout habitat, enhance and restore impacted habitat, and raise public awareness
about their current status. These efforts will also benefit other native stream dwelling
species, because brook trout serve as an indicator for healthy aquatic ecosystems.
Fortunately, it is believed that New Hampshire has more intact populations of brook trout
when compared to the southern portions of the species eastern U.S. range. However,
information to quantitatively describe the status of brook trout populations in central New
Hampshire is limited.
Project Justification
As with several fish and wildlife species found in New Hampshire, the presence or
absence of wild brook trout populations can indicate the condition of aquatic habitat and
water quality. Brook trout depend on cool, clean, and well oxygenated rivers and
streams and can be very sensitive to environmental perturbations which may occur at
rates ranging from instantaneous to gradual. Information collected on this species
enables us to view the occurrence (or lack of occurrence) of brook trout as a sentinel
species that represents the health of aquatic ecosystems, as well as our footprint on the
landscape.
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
Brook trout are susceptible to changes in water chemistry and alterations to their physical
habitat. Unfortunately, these changes to water chemistry and aquatic habitats may be
difficult to recognize. Unlike a toxic chemical spill that may immediately kill aquatic
organisms, the more common attributes that displace brook trout populations occur very
slowly with no clear sign of obvious impact. Changes to natural stream substrate can
significantly reduce the ability of a wild brook trout population to survive and/or
reproduce. Excessive sedimentation from a variety of sources can embed and cover
natural stream features in which brook trout have evolved to depend on. When this
occurs, spawning locations, stream macroinvertebrates, cover, and holding areas can be
lost or impacted negatively. The habitat needs of wild brook trout coincide with our own
desires to protect the quality of water supplies and recreational areas.
The brook trout is also an important game fish and symbolic figure in the heritage of New
Hampshire. Records illustrating the importance of the species as a food source and sport
fish in New Hampshire date back to the 17
th
century. Even today, the species is
consistently one of the most highly pursued fish for freshwater anglers in the state.
Additionally, the brook trout has been designated as the state fresh water fish.
Assessment of Wild Brook Trout Populations
To assess the status of brook trout within the Winnipesaukee River drainage, the New
Hampshire Fish and Game Department (NHFGD), in partnership with the Lakes Region
Planning Commission conducted electrofishing surveys between 2008 and 2010. The
scale used in the Eastern Brook Trout Joint Venture required that the Lake
Winnipesaukee drainage be divided into thirteen watersheds. These watersheds include:
Alton Bay, The Broads, Center Harbor, Lake Waukewan, Meredith Bay,
Moultonborough Bay, Moultonborough Inlet, Paugus Bay, Sanders Bay, Silver Lake to
the Merrimack River, Tioga River, Winnisquam Lake, and Wolfeboro Bay.
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
Winnisquam Lake
Tioga River
Silver Lake to Merrimack River
Alton Bay
Wolfeboro Bay
The Broads
Moultonborough Bay
Moultonborough Inlet
Center Harbor
Sanders Bay
Paugus Bay
Waukewan Lake
Meredith Bay
Watersheds Within the Winnipesaukee
River Drainage (HUC12 level)
Alton
Ossipee
Hill
Gilford
Meredith
Wolfeboro
Gilmanton
Moultonborough
Tuftonboro
Sanbornton
Andove r
Effingham
Belmont
Mi l to n
Wakefield
Br is tol
Freedom
Franklin
Laconia
Holderness
New Durham
Plymouth
New Ham pton
Hebron
Alexandria
Ta m w o rt h
Brookfield
Northfield
Tilton
Groton
Middleton
Bridgewater
Ashland
Salisbury
SandwichCamptonRumney
Center H arbor
D
an b u r y
Farmington
Barnstead
Canterbury
Madison
To summarize wild brook trout populations at the watershed level, each of the thirteen
watersheds were further divided into smaller drainages called catchments. Attempts were
made to survey every catchment with an established perennial stream. Streams with
depths greater than 3 feet and intermittent flowages could not be effectively surveyed
with backpack electrofishing gear. Length and weight data was collected on each fish
sampled. Information that illustrates the current brook trout habitat condition was also
collected.
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
Surveyed Areas within the
Winnipesaukee River Drainage
Locations of Fish Surveys
Watershed Boundries Within the
Winnipesaukee River Drainage
Alton
Ossipee
Hill
Gilford
Meredith
Wolfeboro
Sandwich
Gilmanton
Moultonborough
Tuftonboro
Andover
Sanbornton
Milton
Effingham
Wakefield
Belmont
Franklin
Bristol
Freedom
Laconia
New Durham
Alexandria
Northfield
New H ampton
Hebron
Tamworth
Brookfield
Danbury
Tilton
Salisbury
Middleton
Bridgewater
Ashland
Farm in gton
Barnstead
Canterbury
Campton
Holderness
Groton Plymout h
Center Harbor
Loudon
Madison
Warner Boscawen
Results
The Complete Winnipesaukee River Watershed
Data from 93 river and stream survey locations are available to help describe the status of
wild brook trout and the general fish community within the Winnipesaukee River
watershed. A total of 24 different fish species have been documented. These species
include: brown bullhead (horn pout) (Ameiurus nebulosus), bluegill (Lepomis
macrochirus), blacknose dace (Rhinichthys atratulus), bridle shiner (Notropis bifrenatus),
burbot (cusk) (Lota lota), hatchery brown trout (Salmo trutta), creek chub (Semotilus
corporalis), creek chubsucker (Erimyzon oblongus), common shiner (Luxilus cornutus),
common sunfish (pumpkinseed) (Lepomis gibbosus), common white sucker (Catestamers
commersoni), wild brook trout (Salvelinus fontinalis), hatchery brook trout (Salvelinus
fontinalis), eastern chain pickerel (Esox niger), fallfish (Semotilus corporalis), golden
shiner (Notemigonus crysoleucas), lake chub (Couesius plumbeus), landlocked salmon
(Salmo salar), largemouth bass (Micropterus salmoides), longnose dace (Rhinichthys
cataractae), rainbow trout (Oncorhynchus mykiss), slimy sculpin (Cottus cognatus),
yellow bullhead (Ameiurus natalis), and yellow perch (Perca flavescens). No fish were
captured at nine of the survey locations. The state threatened bridle shiner was found in
Coffin Brook (Alton). Wild brook trout were the species most frequently encountered at
63% of the surveys (59 of 93 surveys found wild brook trout). Overall, species
abundance within the Winnipesaukee River watershed was most strongly represented by
blacknose dace (42.0% of total number of fish captured) and wild brook trout (33.0% of
total number of fish captured). Burbot were the least abundant species captured (0.02%
of total number of fish captured).
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
Looking at Wild Brook Trout at a Finer Scale
Brook Trout Presence/Absence Information
To explain the current status of wild brook trout at the watershed level, fish data from
each catchment surveyed was assembled. Since the roughly 464 miles of stream within
these thirteen watersheds could not be completely surveyed, the assembled fish data was
used to illustrate a representative description of the entire watershed. The number of
survey sites varied between watersheds based on the number of catchments
(http://nh.water.usgs.gov/projects/sparrow/data/catchments_metadata.htm) and
availability of streams suitable for electrofishing within each of the thirteen watersheds.
Surveys were focused at the approximate midpoint of each catchment. There are several
advantages of using the scale of catchments for survey locations. The catchment model
divides watersheds into smaller stream reaches based on drainages. Within each of these
units, information has been already developed to describe several features related to
effects on water quality. Land-use (% developed, % agriculture, % forested),
atmospheric deposition, physical characteristics (size, slope, % wetland), and other
variable data are available to quantify estimated nutrient loading. Eventually, it is
expected that a regional model will be developed to predict fish species presence or
absence in areas with no survey information based on catchment data attributes and fish
survey data from other locations.
Wild Brook Trout Presence/Absence at the Catchement
Level within the Winnipesaukee River Drainage
Wild Brook Trout Captured
No Wild Brook Trout Captured
Catchme nt No t S urveyed*
Watershed Boundary (HUC12 level)
Alton
Ossipee
Hill
Gilford
Me re d it h
Sandwic h
Wolfeboro
Campton
Gilmanton
Andover
Moultonborough
Tuftonboro
San bornton
Rumne y
Freedom
Milton
Effingham
Belmont
Wakefield
Br is tol
Franklin
Groton
Laconia
Alexandria
Holderness
New Durham
Plymouth
Tamworth
New Hampt on
Hebron
Northfield
Brookfield
Tilt on
Middleton
Bridgewater
Salisbury
Ashland
Danbury
Center Harbor
Farmin gton
Madison
Barnstead
Canterbury
Wi lmot
Wi lmot
Eaton
* Catchment not surveyed due to intermittent flow, lack of access, stream type not suitable for backpack electrofishing survey
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
The surveys show habitat quality for wild brook trout varies by watershed throughout the
Winnipesaukee River drainage. Currently, wild brook trout are not necessarily rare in
central New Hampshire, but the projected status of wild brook trout in some parts of this
drainage is exceptionally good. Due to limitations associated with backpack
electrofishing gear, stream type, lack of public access, and stream flow, not every
catchment could be surveyed within each of the HUC12 watersheds. The table below
summarizes the number of catchments surveyed and the status of the wild brook trout
populations within. The number of catchments within each watershed varies greatly
throughout the Winnipesaukee River Drainage. The large lakes that encompass a
significant amount of area within some of the watersheds can minimize the percentages
of stream/river to be surveyed within some watersheds.
Watershed name Number of
surveys
# of Surveys where
wild brook trout
were found
Percentage of
catchments with wild
brook trout
Alton Bay 8 3 37.5
The Broads 8 6 75
Center Harbor 1 0 0
Lake Waukewan 3 2 66.67
Meredith Bay 3 0 0
Moultonborough Bat 8 6 75
Moultonborough Inlet 9 6 66.67
Paugus Bay 2 0 0
Sanders Bay 1 0 0
Silver Lake to Merrimack River 12 10 83.33
Tioga River 12 8 66.67
Winnisquam Lake 13 8 61.54
Wolfeboro Bay 13 10 76.92
Wild Brook Trout Density and Recruitment
An additional analysis that illustrates the health of wild brook trout populations is
population density. In streams where wild brook trout were found, density calculations
were performed. The results ranged between 0.13 (Tioga River, Belmont) to 94.17
(Cook Brook, Moultonborough) brook trout/100 square meters. No clear pattern for
brook trout density by watershed is apparent. The ten most dense brook trout streams
were found in five different HUC 12 watersheds. Similarly, the ten streams with the
lowest brook trout densities were from five different watersheds.
The ability for wild brook trout to reproduce is imperative for a population to be self-
sustainable. A population consisting of various age and size classes is an indicator of
good habitat condition. Water quality and habitat types must be suitable to support all
life stages of fish to sustain the population. Sustainable populations show the habitat
present provides ample amounts of forage, thermal refuge, spawning gravel, cover from
predators, and from various weather impacts (flooding, frazil ice, etc.). Flows that have
been amplified by impervious surface and constriction during stormwater runoff events
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
can scour areas where eggs have been deposited. This impact can also compromise
reproductive success by increasing sediment and silt (associated with upstream erosion)
depositing on eggs, causing suffocation.
Scale samples can be taken and analyzed to determine the age class structure of brook
trout in a stream. This analysis goes beyond the scope of our assessments but the
collected data can provide some indication on the population’s ability to reproduce. As a
surrogate to scale samples, a length metric can be used to indentify presence of juvenile
fish hatched earlier in the year of the electrofishing surveys. A brook trout less than 90
millimeters is routinely expected to be a young of the year fish. Of the 59 streams where
wild brook trout were detected, 47 of them contained young of the year brook trout
(having at least one brook trout with a length <90mm).
Observed Impacts to Water Quality and Brook Trout Habitat
Current aquatic habitat conditions can be evaluated with modern day mapping software,
but on the ground survey work is imperative to obtain a more complete sense of the
health of aquatic systems. Survey crews have documented several alterations to the
habitat and water quality that exists within the surveyed locations of the Winnipesaukee
River drainage. These alterations range from clearly visible current impacts, to historic
land use practices that have altered the landscape and its drainage for an incalculable
period of time. Potential impacts to wild brook trout were recorded at every survey
location. The lack of riparian vegetation, as a result of logging, lawns, parking lots, or
adjacent road proximity, was the most common impact recorded. Impacts associated
with erosion (scouring, sediment deposition, etc.) were routinely observed at these
locations. Other observations noted were perched culverts, vehicles crossing through the
streams, extensive stream bank armoring using riprap, washed out pavement entering the
stream and litter.
As with most of New Hampshire, much of the land within the lakes region was cleared
for cropland and livestock grazing. In as early as the 17
th
century, the water retaining
ability of old growth forests with thick layers of moss and detritus was becoming altered
by the hand of man. The once slow absorption of water from rain and snowmelt which
kept water tables high throughout the year was replaced by readily drained plowed fields
carrying sediment laden runoff to aquatic systems. It is likely these rivers and streams
were afforded minimal riparian buffers. The loss of recharge to water tables caused
stream flow rates to drop in the summer months. Countless streams were reconfigured to
generate water powered mills, creating impoundments that resulted in warmer water
temperatures and fragmentation of aquatic habitats. Signs of these historical practices
were observed at several of the surveyed locations. Stonewalls, barbed wire, and mill
structures were frequently documented.
The impacts on aquatic systems associated with modern day activities can be very similar
to those which occurred centuries ago. Increased concentrations of impervious surfaces
prohibit rain and snowmelt to infiltrate soils and recharge ground waters. Instead,
streams become flashy; significantly increasing in flow rate directly after storms or
melting events and then quickly returning to low flow levels. These large flushes of high
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
water can increase erosion and sedimentation rates on streams. Additionally, runoff from
impervious surfaces can introduce quick bursts of nutrients, petroleum hydrocarbons,
warmer water temperatures, sand, chlorides, etc., into aquatic systems. Even low
percentages of impervious surfaces (as low as 4% of watersheds) can significantly
influence the presence or absence of wild brook trout. Stormwater drainage systems that
convey runoff directly into streams were routinely observed during surveys within the
Winnipesaukee River drainage. These were often associated with road/stream crossings
or areas where development left minimal riparian buffer. Drainage from impervious
surfaces should be directed away from aquatic systems to reduce the negative impact on
aquatic communities.
There is a wide variety of stream crossing structures throughout the Winnipesaukee River
Drainage. In some instances, stream crossings that were designed only to incorporate the
passage of water flow can alter both stream habitat and aquatic communities. In addition
to the ability for a crossing to facilitate the passage of a certain rate of flow, stream
crossing design should also consider the specific geomorphic properties of the stream in
question. Natural stream systems are in states of evolution or adjustment. Beyond water,
streams are employed to convey organic (wood, leaves) and inorganic (sand) material.
Several impacts related to crossing designs that do not incorporate the geomorphology of
a stream include: culvert perching, scouring and sedimentation, blockage, undermining,
road overtopping, and failure. Although the capital costs associated with a geomorphic
design are expected to be larger, it is expected that costs related to maintenance overtime
and replacement would be much less.
The most suitable stream crossing for fish is one that does not exist. Road design should
first consider ways to avoid streams. If a stream crossing is unavoidable, designs should
attempt to make the crossing invisible to the stream. Flow rate, sediment transport,
gradient, water temperature, and substrate should be identical within the crossing
structure to the reference condition of the stream. Impacts to fish communities and
habitat result when these conditions become altered. Undersized culverts that constrict
streams and increase flow rates (particularly during storm flow events) often create scour
pools (or perching) at the culvert outlet. Overtime, these can become barriers to fish
movement. This scenario was observed at several of the locations surveyed. If a fish
manages to access the culvert, flows may be too overwhelming for the fish to navigate
through it. The creation of barriers can lead to wild brook trout not being able to access
more desirable habitats for spawning, refuge from warm water temperatures, forage
areas, etc. As a result, the population could become extirpated.
Wild brook trout are not often thought of as migratory fish and subsequently not often
considered during roads design. However, radio telemetry studies in New Hampshire
have shown larger wild trout can move over 20 miles in a single year. When a population
becomes isolated, concerns regarding gene flow are also present.
If a catastrophic event occurred upstream of an impassable barrier (i.e. dam, perched
stream crossing) that decimated a wild brook trout population, fish may not be able to
repopulate the area. This is of particular concern to the streams of this region. Several
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
smaller streams that flow directly into the larger lakes in this drainage appeared to be
suitable for wild brook trout but none were found. If a population lives in a high order
stream that flows directly into these waterbodies and a stressful event occurs (i.e. acid
flush event from snowmelt, extreme drought year, large plumes of sediment, etc.), the
ability to repopulate the area may not exist.
Multiple dams exist within the Winnipesaukee River drainage for a variety of purposes
(i.e. hydro power, recreation, farm pond creation, water supplies, etc.). Beyond the
obvious impact of habitat fragmentation, impoundments have the ability to alter water
chemistry and habitat. Outlets of dams can supply oxygen deficient water at increased
temperatures to downstream reaches. Upstream sections can be converted to shallow
wetlands that displace brook trout. Although more commonly observed in lake and pond
environments, human delivered nutrient inputs can lead to eutrophication in rivers and
streams. While the simple dynamics of flow provide aeration and dissolved oxygen to
streams on most occasions, excessive growth of algae can slow flows, allowing oxygen
levels to become reduced.
Local Strategies for the Conservation of Wild Brook Trout
Land conservation and guidance on land use practices are essential to protecting brook
trout habitat. Wild brook trout populations and humans can coexist, but concerted efforts
must be made to limit impacts to the brook trout habitat. Land and water use guidance
should be given for streams of all sizes within a watershed. Presumably, minor human
impacts to smaller streams can be additive throughout the watershed and create problems
that are not readily apparent until further downstream. Land use practices have to occur
in ways that minimize their impacts on brook trout and their habitats. The cost to restore
a population of any species is always higher than the cost to protect them. Restoration
actions require a great deal of effort and may not always guarantee self-sustaining
populations would return.
Headwater Stream Protection
The level of protection for headwater streams varies by town and is usually accomplished
through zoning ordinances. Local zoning ordinances should be reviewed to determine
whether they provide sufficient protection. Best management practices for agriculture
and silviculture should also be promoted among landowners who abut headwater streams.
Local environmental stewards need to be attentive and vocal when projects are proposed
within the watershed that could impact aquatic systems. The Comprehensive Shoreline
Protection Act (RSA 483-B) already offers some regulatory protection for the
Merrymeeting, Red Hill, and Winnipesaukee rivers (as well as several lakes and ponds)
within the drainage. At a minimum, 100 feet (30 meters) of naturally vegetated buffers
along all streams should be maintained. Preferably, vegetated buffers should be 300 feet
(~100 meters). As buffer widths increase, more terrestrial species will use the wooded
area as a travel corridor.
Additionally, riparian vegetation slows sediment and pollutant laden stormwater before it
enters an aquatic system. Stormwater drainage designs that discharge directly into the
stream should be avoided in favor of systems that filter stormwater into the ground (i.e.
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
rain gardens, properly designed catch basins). Maintaining larger riparian areas also
allow the ability for trees to fall into streams. The presence of large woody debris creates
pools, cover, stream bank stability and complex habitat for fish species. When wood
cover is allowed to persist in streams it may also slow and retain nutrient particulates.
Taking steps to protect headwater streams will prevent irreversible losses to New
Hampshire’s biodiversity, as well as save countless dollars by protecting water quality
and preventing flood damage. Therefore, communicating these protective measures to
local policy makers is imperative.
Restoration
Efforts should also be implemented to restore riparian buffers and stabilize banks. These
restoration efforts will protect both aquatic habitat and water quality. Since the demand
for more development and land alteration and their subsequent strains put on aquatic
systems is expected to continue throughout the lakes region, the need to provide systems
that slow, stabilize, and infiltrate flows will always be needed. There are several
different options and resources available to help guide the reestablishment of riparian
areas and bank stabilization. As fisheries resource managers, we believe prioritization
should be given to those streams where wild brook trout and/or species found on the
state’s threatened and endangered list exist (i.e. Coffin Brook in Alton).
Stream Crossing Inventories
Stream crossings should be evaluated within the Winnipesaukee River drainage to
determine if they are degrading habitat and/or obstructing fish passage. Stream crossing
inventories used in conjunction with fish survey data can be used to determine the level
of degradation of aquatic habitat as well as provide restoration focus areas. This should
be communicated to local road agents and the New Hampshire Department of
Transportation so that stream crossing upgrade projects can be developed, prioritized, and
implemented.
Public Outreach and Education
Educational programs should be developed that inform both children and adults about the
importance of the link between wild brook trout presence and good water quality.
Educators should emphasize the realization that environmental impacts caused by one
person or one family in the Winnipesaukee River drainage could have a lasting effect on
them and their neighbors downstream. The key is to stress the needs of the wild brook
trout, a focal species that is the essence of New Hampshire’s rich heritage.
For More Information
Interested individuals and groups are encouraged to request site specific information by
contacting the Inland Fisheries Division at New Hampshire Fish and Game (phone (603)
271-2501 or email [email protected]
).
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
Useful Information:
New Hampshire Stream Crossing Guidelines:
http://www.unh.edu/erg/stream_restoration/nh_stream_crossing_guidelines_u
nh_web_rev_2.pdf
Importance of Shoreline Protection and Buffers, The NH Department of
Environmental Services:
http://des.nh.gov/organization/divisions/water/wmb/repp/documents/ilupt_ch
pt_2.6.pdf
Buffers for Wetlands and Surface Waters, A Guidebook for NH
Municipalities:
http://www.nh.gov/oep/resourcelibrary/referencelibrary/b/buffers/documents/
handbook.pdf
New Hampshire Strategies for the Conservation of Wild Brook Trout
Habitat:
http://www.easternbrooktrout.org/docs/EBTJV_NewHampshire_CS.pdf
Photos from Surveys
An example of a wild brook trout captured in a stream flowing through Belmont.
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
An example of a perched stream crossing in Gilmanton where various fish species may
have difficulty accessing essential habitats throughout the year.
A stream crossing that facilitates fish passage in Belmont (note the natural stream
substrate within the stream channel under the crossing). The established riparian buffer
seen here also promotes good water quality while providing shade to keep stream
temperature cool.
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
Trees allowed to fall and remain in stream systems provide ideal habitat features (food
sources and protective cover) for wild brook trout. These features can also help dissipate
erosive forces.
The state threatened bridle shiner captured at Coffin Brook, Alton.
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
The New Hampshire Fish and Game Department conducting a stream backpack
electrofishing survey.
The removal of vegetation along a stream corridor (seen here in Gilford)
can increase stream temperatures and allow sediment from runoff to enter
streams. Excessive sedimentation can fill important spawning gravel and
essential pool habitats.
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
The loss of riparian buffers along stream corridors allows pollutants associated with
parking lots a pathway to enter streams and lakes. Pulses of very warm water,
particularly from storm events after a warm day can shock wild brook trout and other
fish species. Impermeable surfaces can increase erosion and sedimentation rates as
well as decrease ground water recharge rates.
Winnipesaukee Brook Trout Surveys 2010 NH Fish & Game
Brook Trout Captured N=1018
Brook Trout Not Captured N=1009
NH Wild Brook Trout Distribution*
*Data from NH Fish and Game, NH Department of Environmental Services and the US Forest Service (1983-2010)
