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- Duke Power Company
Contact: Dave Coughlan (704) 875-5236, djcoughl@duke-energy.com
Hydroacoustics - We continue to use
hydroacoustics and purse seining to evaluate reservoir forage fish
populations. Forage fish densities are derived by echo
integration. Purse seine data provide species composition and
length frequency distributions for correlation with target strength
values.
We are working cooperatively with North Carolina
State University (NCSU) and NC Wildlife Resources Commission (NCWRC)
on a bioenergetic comparison of two reservoir striped bass
populations. One population resides in a eutrophic reservoir with
abundant prey and frequent summer die-offs of stripers while the other
is in an oligotrophic cooling reservoir with less abundant forage and
infrequent summer die-offs. Calorimetric analyses of striped bass and
forage fish are being conducted in addition to population estimates of
forage fish. Jessica Thompson, a NCSU PhD student, is working on this
project.
An additional hydroacoustic question deals with the
stability of forage fish populations (blueback herring and threadfin
shad) over time in an oligotrophic reservoir experiencing a prolonged
drawdown. Jocassee reservoir in upstate SC has been 20 ft below full
pool for over one year and concerns exist that the forage populations
may be more susceptible to entrainment during pumping operations at a
pump-storage hydroelectric facility. Twice annual hydroacoustic
surveys (March and November) for many years have demonstrated high
population estimates in November and very low numbers the subsequent
spring. Despite the particularly cold winter of 2000-2001 and very low
water levels (23 ft. below full pool) the population rebounded to
characteristic late-year population levels and indicated a dynamic
population that is stable through time. Contact DJC or Hugh Barwick
(704) 875-5459 for more details.
Fish-Friendly Piers - Piers represent sources
of structure and cover for reservoir fish populations, the importance
of which appears to be increasing as some reservoirs experience rapid
residential shoreline development. We have formed a partnership with
NCWRC, NC Wildlife Habitat Foundation, Bass Pro Shops, Pure Fishing,
NC BASS Federation, NC State University, USGS, and B.A.S.S. Inc. to
evaluate the feasibility of enhancing shallow-water fish habitat by
creating fish-friendly piers. These are piers with added structure
(e.g., Berkley Fish Habs with and without brush) beneath the pier to
provide additional cover for fish. Fish were sampled from all piers
and transects in April, July, and October 2001. Generally, throughout
all seasons, catch rates were higher at brushed 'hab' piers and 'habbed'
piers sites than at reference pier sites. Similarly, fish abundance
was generally higher on transects containing woody debris, brushed hab
piers, or habbed piers than transects containing reference piers
during spring and summer. However, few differences were observed
during fall. On these reservoirs, fish abundance associated with
developed shorelines appears to be related to the structural
complexity of the habitat, even though the composition of the
structure differs. Bob Barwick, a NCSU MS student, has evaluated fish
use of these piers and is currently writing his thesis. Contact Hugh
Barwick for more details (704) 875-5459.
Blue Catfish Tracking - Duke Power and NCWRC
are working cooperatively with Virginia Tech to study the movements of
blue catfish in a large multi-use reservoir (Lake Norman, NC). Joe
Grist, an MS student at VA Tech, has released radio-tagged blue cats
and has been tracking them every two weeks for almost a year to get an
idea of diurnal and seasonal movements. An understanding of blue
catfish movement may give us a better idea of the feasibility of a
blue catfish population estimate at some time in the future. The study
is scheduled to conclude in the next few months.
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-
Kentucky Department of Fish and Wildlife Resources
Jeff Crosby, #1 Game Farm Road, Frankfort, KY 40601
jeff.crosby@mail.state.ky.us
- Advanced Fingerling Largemouth Bass Stocking in
Three Infertile Eastern Kentucky Reservoirs
Jeff Ross, Fisheries Research Biologist,
jeff.ross@mail.state.ky.us,
1-800-852-0942 ext. 361
Eastern Kentucky reservoirs are generally believed to have poor
largemouth bass fisheries than reservoirs located in central and western
Kentucky. The current study is being conducted to determine if spring
stocking (March) of wild-reared largemouth bass fingerlings (mean length
_ 5.0 in.) can improve year-class strength of age-i largemouth bass in
these lakes and result in an improved largemouth bass fishery. The three
study reservoirs include Grayson, Carr Creek, and Dewey lakes. In this
study, three stocking rates (about 5, 10, and 15 fish/acre) are being
evaluated. Each rate will be stocked in each reservoir during two
randomly chosen years. In addition to the stocking evaluation,
recruitment models are being developed to determine major factors that
influence recruitment in each reservoir.
Each reservoir was stocked at rate of 10 fish/acre in 1999, 5 fish/acre
in 2000, and 15 fish/acre in 2001. At Grayson Lake, 2001 spring
electrofishing samples found 64.5% of all largemouth bass collected to
be stocked fish. When broken down by size-group, the stocked largemouth
bass made up 75.0% of the <8.0 inch bass, 31.9% of the 8.0 — 11.9 inch
fish, and 1.4% of the 12.0 — 14.9 inch fish. At Carr Creek Lake, 2001
spring electrofishing samples found 72.6% of all largemouth bass
collected to be stocked fish. When broken down by size-group, the
stocked largemouth bass made up 90.5 % of the <8.0 inch bass, 46.9% of
the 8.0 — 11.9 inch fish, and 4.9% of the 12.0 — 14.9 inch fish. In
Dewey Lake, 52.6% of the largemouth bass collected in 2001 spring
electrofishing samples were stocked fish. When broken down by
size-group, the stocked largemouth bass made up 78.8 % of the <8.0 inch
bass, 24.8% of the 8.0 — 11.9 inch fish, and 0.3% of the 12.0 — 14.9
inch fish. Stocked largemouth bass, in each reservoir, recruited to the
12.0 — 14.9 inch size-group for the first time in 2001. Percentage
representation of stocked bass in this size-group is expected to
increase in our spring 2002-electrofishing samples.
- Indexing Largemouth Bass Year-Class Strength and
Recruitment to the Fishery
Gerry Buynak, Fish and Wildlife Technical Program Coordinator,
gerard.buynak@mail.state.ky.us,
1-800-852-0942 ext. 354
The largemouth bass are the number one sport fish sought by Kentucky
anglers and are the primary predator found in Kentucky’s public lakes
and reservoirs. Numerous studies have shown that year-class strength
regulates recruitment to the fishery and dictates both anglers catch and
satisfaction with each fishery. Year-class production in Kentucky’s
lakes is highly variable and is impacted by many abiotic and biotic
variables including productivity, hydraulic retention, and food
availability. It is important to remember that year-class production is
not controlled by a single variable, but is the result of a combination
of many factors acting together. The first indication of the strength of
each year class can be obtained in each body of water during the fall of
each year. The primary data needed to begin to build an understanding of
year-class production and recruitment to the fishery in each water body
is catch-per-unit-effort (CPUE or density) of all sizes of age-0 bass,
CPUE of large age-0 bass, and mean length of age-0 fish. Each of these
variables play a role in over-winter survival and subsequent year-class
strength of bass at age 1. Work on Kentucky reservoirs and reservoirs
throughout the country indicate that if a year class is strong at age 1
it will remains strong in future years and provide for increased angler
satisfaction. The opposite will be true if weak year classes are
produced especially when weak year-classes are produced in successive
years.
Knowledge of year-class strength, variables affecting year-class
production, and recruitment to each fishery is essential to developing a
pro-active management approach which includes fingerling largemouth bass
stockings. Studies completed at Taylorsville Lake and ongoing studies at
Dewey, Carr Creek, and Grayson lakes indicate that largemouth bass
fingerling stockings maybe a viable management option that can provide
positive benefits to largemouth bass populations and angler catches and
eventually result in increased angler satisfaction. These studies
indicate that stocking can be used as a viable management option to
moderate declines in densities of largemouth bass especially if natural
year-class production is low. It must be pointed out, however, that
these studies have also shown that stocking of largemouth bass on a
strong natural year class has negative impacts on both wild and stocked
fish and ultimately reduced year-class strength at age 1. Thus it is
important to know the relative strength of each years class to best
manage each fisheries. In order to prepare for a scientifically based
pro-active largemouth bass stocking management program, the following is
needed.
The objectives of this program are to: 1) determine and better
understand black bass year-class production at age-0, 2) determine age-1
carrying capacity for each body of water, 3) model relationships between
age-o fish and densities of age-1 fish, 4) model relationship between
age-1 fish and recruitment to the fishery at each lake, 5) determine if
remedial fingerling largemouth bass stockings are needed to supplement
natural year-class production in each water body, and 6) to inform
anglers on future trends in each fishery.
- Evaluation of Timing of Prey Availability Relative
to Walleye Stocking in Kentucky Impoundments
Jeff Ross, Fisheries Research Biologist,
jeff.ross@mail.state.ky.us,
1-800-852-0942 ext. 361
Dave Dreves, Fisheries Research Biologist,
dave.dreves@mail.state.ky.us,
1-800-852-0952 ext. 363
A lake strain of walleye is currently being stocked in seven Kentucky
reservoirs with coolwater habitat. Fingerling walleye are stocked in May
at 25-42 mm. These fisheries have been disappointing in terms of total
return and catch rate. A possible limiting factor for predator survival
is the availability of suitable prey. The Kentucky Department of Fish
and Wildlife Resources is interested in refining walleye stocking
protocols to synchronize stocking with periods of peak prey abundance.
The objectives of our study are to evaluate and quantify the temporal
abundance patterns of gizzard shad in tow eastern and two western
Kentucky impoundments. Quantify the gape width limitation of fingerling
walleye and use this to evaluate synchrony of stocking with
morphologically consumable prey. Quantify the survival from stocking to
age 1of several cohorts of walleye over a temporal range of different
available prey sizes.
The study is currently in it final (third) year. Walleye were stocked on
two dates each year in early and late May. Otoliths of stocked walleye
were marked with oxytetracycline to distinguish early from late stocks.
Walleye gape width was used in conjunction with larval body depth of
gizzard shad to identify peak periods of available shad forage. Gizzard
shad were sampled from late April to mid-June using a neuston net and
were enumerated and measured for length. Temperature and secchi depths
were also measured from late April to mid-June. Walleye were sampled
from October to December using electrofishing gear to collect data
necessary to determine relative survival of early and late stocked
walleye. Otoliths collected form young of the year walleye were analyzed
for oxytetracycline marks.
Results up to this point continue to point towards much higher survival
of the late stocked (late May) walleye. This later date is essentially
the longest our hatcheries can hold walleye due to double cropping of
ponds. Walleye size at stocking in 2001 averaged 27.6 mm for the early
May and 41.2 mm for the late May stocking. In each year, survival of
walleye till fall has been dramatically biased towards the late May
stocked fish with 72-99% of the returns coming form these fish.
Yearly variation in timing of shad availability does not seem to
correlate with the survival of the early stocked walleye. Size and
condition of walleye at time of stocking appears to play a major role in
their survival in Kentucky reservoirs. The two-week difference in
stocking dates is all it takes to produce such disparity in survival of
our stocked walleye. Gizzard shad density may, however, act as a buffer
against predation of stocked walleye. In each year, shad densities have
been low at the time of the early walleye stocking. Early stocked
walleye may therefore be subjected to heavy predation as they are
extremely vulnerable at the time. Handling/stocking mortality does not
appear to be a factor as we found less than 5.0% mortality for either
group of walleye 24 hours after stocking.
Further data analysis should provide a better insight into the
mechanisms affecting stocked walleye survival in Kentucky reservoirs.
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Lead Net Evaluation for Crappie Sampling - Gears
currently used to assess fish populations (frame nets, gill nets,
electrofishing, and rotenone), are not providing adequate crappie CPUE to
provide accurate appraisals of population characteristics. Current gear
types also create bias for certain length groups within a population.
A sampling technique is needed that will provide maximum
CPUE for man-hours expended and will provide unbiased data for all length
groups of crappie. A series of lead nets with mesh sizes from 0.5”–2.0”
have the potential to provide adequate catches of crappie, and may be more
efficient than frame nets in providing data needed to assess crappie
populations. Sampling was conducted in Caney Creek Reservoir to compare
CPUE of frame nets and the lead net series. Results are encouraging.
Sampling will be expanded to at least three reservoirs in Fall 2002.
Artificial Reefs From Feed Pallets
- Many of our Louisiana impoundments have long since lost their
available complex cover. To that end, LDWF is now in the process of
developing guidelines to address construction and deployment of artificial
reefs. Our primary concern is that materials or methods used under the new
guidelines initiate no environmental consequences. The materials used must
be readily available, inexpensive, durable, easy to handle, and provide
maximum structural complexity.
Plastic feed pallets have met those criteria and are
showing high potential for success. Reefs of the pallets will be deployed
in at least three Louisiana reservoirs in 2002.
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- F-41-R-24 FACTORS INFLUENCING FISH POPULATIONS IN OKLAHOMA WATERS (Ok. State Coop
Unit - Dana Winkleman danaw@okstate.edu)
- Project 23: Evaluation of the Flathead Catfish Population and Fishery on Lake Carl Blackwell, Oklahoma, with Emphasis on the Effects of Noodling
- Project 26: Texoma Striped Bass Spawning & Recruitment
Evaluation: An evaluation of differences in habitat preferences among larval striped bass in the Red River and Washita River arms of Lake Texoma.
- Project 27: Texoma Striped Bass Spawning & Recruitment
Evaluation: An evaluation of differences in survival and recruitment of
larval striped bass between the Red River and Washita River arms of Lake
Texoma.
- F-50-R-8 FISH RESEARCH FOR OKLAHOMA WATERS (Oklahoma Fishery Research Lab - Greg
Summers gsummers@odwc.state.ok.us)
- Project 14: Texoma Striped Bass Spawning & Recruitment
Evaluation: Identification of spawning locations in the Red River and Washita River arms of Lake Texoma.
- Project 16: Texoma Striped Bass Spawning & Recruitment
Evaluation: An evaluation of differences in striped bass egg production
between the Red River and Washita River arms of Lake Texoma.
- Project 17: Development of a GIS database to evaluate spatial differences in angler
participation and license buying patterns.
- Project 18: Evaluation of a White Perch invasion of Kaw Lake.
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