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- West Virginia - Kevin
Yokum, West
Virginia Division of Natural Resources, P.O. Box 38, French Creek, WV 26218; kyokum@onlinewv.com
- In WV we are currently experiencing what could be the worst drought to hit our
state this century. Water level in our rivers and streams are at a historical low. We are
under pressure to allow water withdrawal from any water body larger a 5 gallon bucket. We
are currently allowing withdrawal from federal water bodies which don’t have
recreational users (NRCS and Soil Conservation flood control impoundments). If conditions
don’t change soon we will be forced to allow water withdrawal from our reservoirs
which are already below normal summer pool level. At this point some small fishkills are
occurring and large kills are pretty much inevitable if conditions don’t improve.
- A Walleye study to determine cost/benefit of stocking fry or fingerlings is
underway. This year approximately 7,000 two inch fingerlings were marked and released in
Stonecoal Lake. We will continue this project and evaluate the fry vs. fingerling argument
in terms of cost, labor and benefits on the fishery over the next 5 years.
- Hydro development on Summersville Lake, the largest lake in WV, is going well as
the contractors are sticking to our mitigation agreement and all potential problems have
been dealt with quickly and effectively. Open communication has helped as we meet with the
contractor and developer monthly.
- Our current program of adding lime to streams where acid deposition or mine
drainage has damaged streams has been very effective in reclaiming over 50 miles of trout
water. Two new rivers, the Gauley and Cherry rivers, have been added to the project.
Liming of these rivers, which eventually find their way into Summersville Lake, could have
a positive effect on water quality in the reservoir.
- Tennessee Tech University -
Steve
Sammons, Tennessee Cooperative Fish and Wildlife Research Unit, Box 5114, Cookeville, TN
38505; ssammons@tntech.edu
Objectives:
1) Identify sampling times and locations for neuston (larval) net sampling in three
reservoirs across the state: Barkley (mainstem), Percy Priest (tributary), and Douglas
(tributary). See of neuston net is effective at predicting year-class strength of fish.
2) Identify contribution to year class for stocked black nosed crappie in at least 4
reservoirs.
3) Quantify 24-hour survival of stocked black nosed crappies.
4) Model effects of 10"-minimum length limit on crappie populations in at least 10
reservoirs across the state. See if a different regulation would be more appropriate,
based on mortality and growth.
5) Quantify relationships between environmental factors and crappie recruitment.
Some Preliminary Results:
- 1998 Larval Sampling:
Neuston net samples detected three orders of magnitude of larval crappie density among
the three lakes, including the highest density of crappie larvae I ever saw (more than 2
per cubic m!). Peak larval catch occurred in same week (mid-May) in all three reservoirs.
Haven’t started comparing these catch rates with standard TWRA trapnet catches yet,
but we do know that neuston net successfully detected poor year class in Barkley.
All three reservoirs were sampled again in 1999, and TWRA crews sampled two additional
reservoirs (Normandy and Norris). Samples have been picked in 3 reservoirs and it is
already obvious that this year crappies did not do as well as they did last year in
Douglas. Normandy also had a poor year class. If our water-level models developed on
Normandy are true, then this would be expected, since 1999 was much drier than 1998.
To identify year-class contribution of stocked black nose crappies, we immersed fish to
be stocked in reservoirs in 500 mg/L of OTC for 6 hours. In fall 1997 we marked 60,000
crappies stocked in Normandy Reservoir. Marking efficacy was 97%. A sample of age-1 fish
was collected in August 1998. Analysis of one otolith per fish by one reader successfully
identified 98% of marked and unmarked fish in a blind test. Marks were formed prior to
annulus formation and were not obscured by annulus-related autofluorescence. Over 90% of
fish from that year class were stocked, suggesting that stocking was successful in
enhancing the crappie population of that lake. A spring 1999 electrofishing sample was
composed of 21% stocked black nose crappies from two stockings (1997 and 1996). We plan to
examine all 1997 year class fish from this sample to determine how well the OTC mark is
holding.
All crappies stocked into three reservoirs (South Holston, Normandy, Woods) and one
500-acre state fishing lake (Graham) were marked in fall 1998 (over 260,000 were marked).
This summer and fall we plan to recapture a sample of age-1 fish and determine stocking
contribution from them.
- 24-Hour Stocking Mortality:
We placed a subsample of 50-100 stocked crappies in 1.2m x 1.2m x 2 m net pens
overnight at 15 stocking locations. We recorded variables such as hauling time, water
temperature, size of fish, etc. The next morning we netted all fish from the pens and
counted dead/alive ones. Each tank on a truck had at least 2 reps, and we tried to cover
the range of hatchery personnel (3 hatcheries). Stocking mortality ranged from 0 to over
90%, but most were under 20% (mean = 17%). We plan to increase our observations this fall
before we analyze this data.
Six reservoirs have been modeled, information for 4 more was collected this spring but
has not been analyzed yet. In each case, a large sample (> 200 fish) was collected
using trapnets or electrofishing, or both concurrently. A subsample of fish from each
place were sacrificed to age using otoliths; ages were assigned to the rest of the sample
using an age-length key. Von bertalanffy and catch curve parameters were calculated from
the sample and plugged into a Beverton-Holt Yield Equilibrium model. Scenarios examined
were no limit (7"), 9", and 10" min. In all cases, the 10" minimum did
not maximize yield once natural mortality was over 30%. In 3 reservoirs, the 9" min
was better at 40 and 50% mortality, in the other three no limit was best. From a search of
the literature, plus our own data, we believe that natural mortality of Tennessee
reservoir crappie populations exceeds 40% on a regular basis. Four more lakes and
reservoirs are scheduled to be sampled this fall for input into the regulation model.
This is still a work in progress. Contact us for more information or check out our web
page at http://www.tntech.edu/www/acad/fish/
and clicking on the Statewide Crappie Evaluation.
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