2000 First Quarter Report
Ohio River Largemouth Bass Studies:
Task 3: Evaluation of Largemouth Bass Stocking in Two Ohio River Embayments

Submitted to:
West Virginia Department of Natural Resources
Division of Wildlife

Submitted by:
Eric C. Janney and Kyle J. Hartman
West Virginia University
College of Agriculture, Forestry, and Consumer Sciences
Division of Forestry
Department of Wildlife and Fisheries
322 Percival Hall, Box 6125
Morgantown WV 26506-6125
(304) 293-2941

Objectives

1. Determine if stocking embayments can be used as a practical management tool to improve the Ohio River largemouth bass (Micropterus salmoides) fishery.
2. Determine whether stocked bass contribute significantly to the catch of largemouth bass by recreational and tournament anglers.
3. Determine if embayment areas can be treated as discrete areas in terms of stocking management units.

Study Area
The embayment areas used for stocking were decided upon by Dr. Kyle J. Hartman in consultation with West Virginia Department of Natural Resources biologists based upon surface area, quality of habitat, and historical fishing pressure. Little Mill Creek (22.6 acres), located in the Racine Pool, and French Creek (118.8) acres, located in the Willow Island Pool, were stocked at a rate of 25 intermediate (mean total length = 178 mm) and 10 adult bass (mean total length = 272 mm) bass per acre. Little Mill Creek is located in Jackson County, and French Creek in Pleasants County, West Virginia. Little Mill and French Creek are both characterized by shallow, turbid water with flooded timber and aquatic vegetation occurring in littoral areas. Both embayments are eutrophic in nature. The forage base for largemouth bass in these areas primarily consist of gizzard shad (Dorosoma cepedianum), various sunfish (Lepomis spp.), and minnow species (Notropis spp.). Primary sport fisheries in the embayment areas include largemouth bass, channel catfish Ictalurus punctatus, white crappie Pomoxis annuluris, and bluegill Lepomis macrochirus.

Background Information
Little Mill Creek and French Creek were stocked on October 20, 1998. Largemouth bass used for this study were purchased from a private aquaculture vendor located in Pennsylvania. The densities at which the bass were stocked was decided upon by the West Virginia Department of Natural Resources based upon the cost of the fish, and historical population densities of largemouth bass in Ohio River embayments (West Virginia DNR unpublished data). Stocking rates were 25 intermediate and 10 adult bass per acre. Thus, a total of 2,671 intermediate-size and 1,111 adult largemouth bass were stocked into French Creek. Little Mill Creek was stocked with 666 intermediate-size and 250 adult bass. Tagging procedures were conducted with the help of fisheries personnel from the West Virginia Department of Natural Resources and West Virginia University at the Palastine State Fish Hatchery.
Return rates, growth, and survival will be compared between the two size classes to determine if significant differences exist. This information will be used to help determine what size bass are most cost efficient in terms of stocking. Past research has indicated that stocking larger fish tends to produce better return rates than stocking fry or fingerling-sized bass. Although larger fish tend to produce higher return rates, they may not prove cost efficient due to high costs associated with rearing (Loska 1982).

1st quarter 2000 summary
This 1st quarter report summarizes data collection efforts and study activities from January 1, 2000 through March 31, 2000. Data were not collected during January and February due unsuitable weather and flow conditions. Data collection efforts were resumed during March 2000. Field data collected during this period included three electrofishing surveys. Also, some preliminary results of this project were presented at the Fifty-sixth Annual Northeast Fish and Wildlife Conference on Monday, April 10 at 3:00 p.m.

Catch per unit effort of wild largemouth bass during 1st quarter electrofishing surveys continued to be high in comparison to previous electrofishing surveys. Mill Creek was sampled on 27 March (120 min. of effort), and French Creek was sampled on 5 March (60 min. of effort) as well as 29 March (85 min. of effort). All black bass species were selectively dipnetted and checked for the presence of "Floy" type tags as well as fluorescent elastomer marks. A total of 58 largemouth bass were captured during 1st quarter electrofishing surveys (28 in French Creek and 30 in Mill Creek). All 58 bass captured during 1st quarter surveys were presumed to be of wild origin. This was based on the lack of either a "Floy" or elastomer tag on any captured bass.

Electrofishing surveys will continue to be conducted in embayment areas located in the Willow Island and Racine Pools to determine what portion of the bass population is currently comprised of stocked fish. Creel surveys and bass tournament surveys will be resumed in April and continue through June 2000 at which time data collection for this project will end.

Preliminary results
Preliminary data from this project suggest that stocked largemouth bass initially created a positive impact on the largemouth bass fishery in the vicinity of the French Creek and Little Mill Creek study sites. The majority of bass captured during Fall/Winter, 1998 electrofishing surveys were of hatchery origin (Figures 8, 9, 10). Also, the majority of bass reported by anglers during fall, 1998 creel surveys were tagged (Figure 11).

Although stocked bass were initially very prevalent in electrofishing surveys, the wild/stocked bass ratio declined dramatically over time. Stocked bass all but vanished from during summer/fall, 1999 creel and electrofishing surveys (Figures 8-10). The data suggest that stocked bass either suffered high mortality rates subsequent to being stocked, or dispersed out of the study areas into main river habitat where chance of recapture is greatly reduced.

Call-in reports by anglers concerning the capture of tagged bass indicate that dispersal rates of the stocked bass are significant (Figure 12). Anglers reported catching tagged bass up to 14 miles away from their respective stocking site. Mean distance from the stocked embayments to reported capture locations was 3 miles. These data contradict previous studies concerning home range size and dispersal of stocked largemouth bass. Most studies regarding the movement of largemouth bass have indicated limited movement in bass populations. Copeland and Noble (1994) reported that the majority of fish tagged in a North Carolina reservoir were recaptured within 58 meters of their release site (Copeland and Noble 1994). Lewis and Flickinger (1967) found that 96% of tagged fish were recaptured within 100 meters of their release site, and that movement away from the point of capture did not increase with time (Lewis and Flickinger 1967).

Food availability may be an important factor in determining home range size and dispersal rates of stocked largemouth bass. Previous studies have shown that home range size is negatively correlated to forage abundance (Savitz et al. 1983). Stocking bass in areas with low forage densities may induce high dispersal rates of the stocked fish. Stocking densities in the embayment areas may also be positively correlated to dispersal rates.

Post-stocking mortality may also have contributed to the observed reduction in occurrence of stocked bass in electrofishing and creel surveys. The majority of tagged bass captured during fall, 1998 electrofishing surveys appeared to be in poor condition. Fungal infection and lesions were observed in some of the tagged bass captured the month subsequent to stocking.

However, post-stocking mortality likely does not account for the disappearance of stocked bass. As reported in previous reports, we held a sample of the bass we were stocking in ponds at the Palestine Fish Hatchery to evaluate tag and mark retention in the fish. After 31 days, approximately 65% of the fish in the pond were still surviving. This survival rate may be an underestimate given that very few (@ N = 5) bass carcasses were recovered in periodic surveys of the holding pond. Thus, significant parts of the loss are unaccounted for and may be due to avian and mammalian predators.

Relative weight indices have been shown to be a good indicator of the overall condition of largemouth bass (Murphy and Willis 1996). Comparing the relative weight of bass at time of stocking to relative weight at time of recapture may provide valuable insight on the viability of stocked fish after they are introduced into a large river system. A Wilcox signed-rank test was used to compare relative weight of hatchery fish at time of stocking to their relative weight when recaptured. There was not enough evidence to indicate a significant reduction in relative weights in recaptured bass (P = .082). This suggests that the stocked bass that survived in the Ohio River were doing well and were not in a state of declining condition suggestive of poor nutrition or poor health.

Perhaps the most telling fact in examining the outcome of this particular stocking is the contributions these fish have made to tournament fisheries. To date, none of the fish stocked in October 1998 have been checked in with any of the many Bass Tournaments held on the Ohio River. Any surviving fish should have attained a size of 12 inches or more, yet none have been checked-in by tournament anglers. Certainly this suggests a very limited contribution by these stocked fish to the Ohio River bass population.

Literature Cited
Copeland, J.R., and R.L. Noble. 1994. Movements by Young-of-Year and Yearling Largemouth Bass and Their Implications for Supplemental Stocking. North American Journal of Fisheries Management. 14:119-124.
Lewis, W.M., and S. Flickinger. 1967. Home Range Tendency of the Largemouth Bass (Micropterus salmoides). Ecology. Vol.48, No.6: 1020-1023
Savitz, J., Fish, P.A., and R. Weszely. Effects of Forage on Home-Range Size of Largemouth Bass. Transactions of the American Fisheries Society. 112:772-776.