Journal of the Southeastern Association of Fish and Wildlife Agencies

Winter stockings of rainbow trout (Salmo gairdneri) in a small (26.3 ha) state park lake were evaluated to determine cost effectiveness of this fishery management technique. A creel survey was conducted to measure fishing pressure and harvest. benefits, in terms of increased hours of fishing provided, increased weight of fish harvested, and increased park entrance revenue, were substantially higher than the cost of stocking.

Characteristics and success of 22 wild brown trout redds were studied in 2 western North Carolina streams. Choice of redd site by spawners was determined and intragravel characteristics of redds were followed throughout the incubation period. Spawning began during the last of October at a water temperature of 7° C. It appeared to have ceased by the middle of November. Redds were selected in pool-riffle transition areas or in riffles with a mean surface velocity of 34 cm/second and a mean water depth of 16 cm. Redd areas averaged 94 cm long and 47 cm wide. Egg pits averaged 31 cm in diameter and were 11 cm deep. During the incubation period, mean intragravel dissolved oxygen was 11.0 mg/1 , permeability 1,367 cm/h and apparent velocity 19 cm/h. About 3 weeks prior to emergence 5 alevins per redd were recovered from one creek and 68 per redd from another. Emergence occurred during the first 2 weeks of April. The number of fry emerging varied from 0 to 22 per redd.

Food habits of smallmouth bass (Micropterus dolomieui) in the New River were studied to compare diet of fish in a minimum length limit regulated section (Virginia) with those in a non-length limit regulated section (West Virginia). Insects were the dominant food type by number for 152-228 mm smallmouth bass in both sections. Numerically, insects were also found to be common in smallmouth bass of several other size categories. Crayfish and fish, however, combined to form a large part of the diet of smallmouth bass greater than 228 mm. Crayfish were a more significant component of the diet of smallmouth bass in West Virginia than in Virginia in the fall 1982 sample. This may be a factor leading to low condition indices of Virginia smallmouth bass and may affect the success of the minimum length limit regulation.

Alewives (Alosa pseudoharengus) and gizzard shad (Dorosoma cepedianum) were the principal prey items in the stomachs of 708 striped bass (Morone saxatilis) collected in Smith Mountain Lake, Virginia, from April to December 1983 and 1984. Alewives comprised 51% and 39% of ingested prey items by number and weight, respectively; comparable values for gizzard shad were 38% and 58%. Stomach contents differed significantly between habitats (upper and lower reservoir) and among seasons. Regression analyses between size of consumed clupeids and total length of striped bass indicated a greater morphological availability of alewives to all sizes of striped bass.

Studies in large and small ponds conducted on the Auburn University Fisheries Research Station from 1981 through 1983 suggest that gizzard shad (Dorosoma cepedianum) severely competed with largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus) populations. Gizzard shad introductions lowered bluegill reproductive success and caused an imbalance the first year of introduction. Gizzard shad grew rapidly through the size range where they were vulnerable to largemouth bass predation; in this 3-year study, largemouth bass were unable to control gizzard shad numbers. Within 2 years after introduction, gizzard shad comprised half the standing stock while replacing portions of the carrying capacity normally occupied by largemouth bass and bluegill. A proposed model of competition is that gizzard shad populations, even at low levels, filtered out enough food items to reduce survival of small bluegill.

Toxaphene and DDTR (DDT plus metabolites), both exceeding 10 ppm wet weight, were found in all samples of fish collected from 9 locations on the Yazoo, Mississippi, National Wildlife Refuge. Concentrations were highest in aquatic systems receiving direct inflow from areas draining agricultural land, and lowest in areas receiving only backwater overflow or local runoff. Residue levels of toxaphene and DDTR were high enough to threaten fish-eating wildlife. Installation of flood control structures around the northern perimeter of the refuge may reduce the inflow of contaminants that now accumulate in resident biota.

Information on silver American eels was obtained over a three-year period from seasonal sampling of 4 Georgia rivers, commercial fishermen, and from systematic sampling of eels migrating from a pond. All silver eels were captured from October through March. Of 80 animals examined, 73 were male and averaged 329mm, 69 g, and 5.5 years. Seven females averaged 584 mm, 448 g, and 8.6 years. These findings suggest that silver eels leave Georgia waters later in the year and at younger ages and smaller sizes than eels at more northerly latitudes.

Trace elements (As, Cd, Cr, Cu, Hg, Pb, Se, and Zn) were measured in fish, clams, and sediment in 1982 to determine whether the effluents from 2 abandoned battery salvage operations were contaminating the Chipola River, Florida. Concentrations of the metals were generally low, but tended to increase downstream from plant sites. Elevated concentrations may reflect residual contamination from the battery salvage operations as well as increased land-use development and proximity to major highways. Concentrations of trace elements in samples of biota and sediments demonstrated no serious contaminant problem in the Chipola River.

The food habits of larval Lepomis spp. and gizzard shad (Dorosoma cepedianum) in Hyco Reservoir, North Carolina, were studied during 1982. Results indicated that Lepomis spp. began feeding at a length of 4 mm on copepod nauplii and the rotifers Polyarthra and Filinia. Selection later (10 mm) shifted to Bosmina, Daphnia, and Mesocyclops, while Diaphanosoma was strongly selected for by all sizes of larvae. The crustaceans Diaptomus, Ceriodaphnia, and Holopedium, along with most rotifers, were not selected. Gizzard shad began feeding primarily on large phytoplankters at 4 mm, then shifted to nauplii and Polyarthra at 5 mm, then to Daphnia at 12 mm. Bosmina and Diaphanosoma were eaten occasionally; and Diaptomus, Ceriodaphnia, Holopedium, and most rotifers were not selected. Both fish species ate significantly greater amounts of zooplankton during the day than at night, and Lepomis spp. ate significantly more zooplankton than gizzard shad overall.

In 1976, the alewife (Alosa pseudoharengus) was stocked in Watauga Reservoir, Tennessee, by the Tennessee Wildlife Resources Agency (TWRA), in an attempt to strengthen the forage base. To assess ecological impacts of the introduction, both age and growth and food habits of alewives were evaluated along with food habits of adult game fishes. The alewife population was composed of 3 age classes (0+, 1+, and 2+). Average back-calculated lengths were 70 mm at annulus I and 103mm at annulus II. No significant differences between sexes were found with back-calculated lengths or with the length-weight relationship (P = 0.05). Alewives fed primarily on cladocerans, copepods, and crustacean eggs in both littoral and limnetic regions. Only one alewife had fish in its stomach. Alewives contributed to the diets of walleye (Stizostedion vitreum), smallmouth bass (Micropterus dolomieui), white and black crappie (Pomoxis spp.), rainbow trout (Salmo gairdneri), and Ohrid trout (Salmo letnica).

Food habits of largemouth bass, (Micropterus salmoides) , from 2 heated East Texas reservoirs having different prey communities were studied. In Lake Monticello, shad, primarily threadfin shad (Dorosoma petenense), were the dominant prey most of the year. Sunfishes were the major food item in winter months. Shad were especially important in the diets of largemouth bass 153 - 306 mm in total length. Utilization of sunfishes increased with size of largemouth bass. Sunfishes and shad were equally abundant in the diets of largemouth bass ≥306 mm TL. Largemouth bass population structure and condition were good based on monthly proportional stock density and relative weight indices. In Lake Welsh, sunfishes were the dominant food of all sizes of largemouth bass, particularly during winter and spring. Many largemouth bass consumed insects during the summer, suggesting low forage fish populations.

Objectives of this study were to collect information on food, prey availability, and growth rates of black bass (Micropterus spp.) and to determine what type of restrictive harvest regulations would be best for their management in Kentucky Lake, Kentucky. The available fish prey/predator ratio (AP/P) in the Blood River embayment was near 1 : 1 until fish reached 300 mm length, and then available prey biomass increased rapidly. Fish prey were the major food item of all 3 species of bass > 150 mm (largemouth bass, M. salmoides, spotted bass, M. punctulatus, and smallmouth bass, M. dolomieui). Length-frequency distributions of bass≥200 mm had a mode of 290 mm, just below the past minimum length limit of 300 mm, and showed that 89% of all bass were less than the new length limit of 360 mm. The distribution pattern was greatly influenced by slow-growing largemouth bass between 2 and 4 years of age.

Food of silver redhorse (Moxostoma anisurum), redbreast sunfish (Lepomis auritus), green sunfish (L. cyanellus), and bluegills (L. macrochirus) was examined to determine whether or not these fish in the Hartwell Reservoir tailwater (Savannah River, Georgia-South Carolina) ate organisms entrained from the reservoir or displaced from the tail water during water releases associated with the production of hydropower. These fish fed primarily on aquatic insects, crayfish, and terrestrial organisms originating from the tail water. Major periods of feeding occurred during nongeneration.

Striped bass (Morone saxatilis) were introduced into 2 East Tennessee lakes to evaluate their survival, growth, and food habits in small impoundments of < 5 ha. Small fingerling striped bass (33-96 mm) introduced late in the growing season exhibited poor survival. Good survival was depedent upon early introduction and larger size at stocking. The preferred habitat of striped bass in small impoundments does not support a sufficient forage base to sustain good growth. Food habit analyses revealed that approximately 85% of all food items consumed by yearling striped bass were fish. Sunfish (Lepomis sp.) comprised 62% of the total fish consumed while 29% were largemouth bass (Micropterus salmoides) and 9% were unidentified fish remains. Striped bass began utilizing fish as a primary food source at approximately 170 mm total length.

Food habits of adult white bass, (Morone chrysops), were studied in Clarks Hill Reservoir from 1 July 1980 to 30 June 1981. Stomachs from 137 white bass ranging from 225 mm to 415 mm total length and 0.12 kg to 0.76 kg were examined. Overall, threadfin shad was the predominant food item of white bass (56% frequency of occurrence). Analysis by season indicated that insect larvae and non-shad fishes were of periodic importance. Similarities were found in frequency of occurrence and seasonal trends. Food habits of white bass were compared to hybrid bass using relative importance indices.

This study was conducted to determine population structure, relative condition, food availability, and food habits of bluegills (Lepomis macrochirus) from West Point Reservoir in 1980 and 1981. Fish were collected with rotenone and by seining 3 times, weekly, from May through September. Zooplankton and benthic samples were collected at each fish sampling site. Scarcity, small size, relative old age, and poor physical condition of the fish indicated that the population was stunted. Results of fish food inventory and gut content analysis revealed a shortage of preferred food for bluegills of all sizes. The food shortage was attributed to competition with the abundant threadfin (Dorosoma petenense) and gizzard (D. cepedianum) shads and to the effects of the annual 3-m water level fluctuation which reduced standing stocks of benthic invertebrates. Fishery management alternatives were discussed.

There is growing interest in the United States to develop fish farming operations using striped bass (Morone saxatilis) and or its hybrids. In South Carolina an aquaculture model was developed to allow production of pan-size (300-450 g) striped and white bass hybrids within a year. Brood fish are grown in captivity, matured, and spawned out-of-season using controlled environment systems. Small juveniles are produced early in indoor intensive nursery systems for stocking of grow-out facilities at the onset of suitable outdoor rearing conditions. Testing of model components indicated that cultured striped bass can be conditioned to spawn out-of-season and that the striped bass and white bass hybrids appear well suited for aquaculture development.

Laboratory bioassays were conducted to estimate lower dissolved solids and temperature thresholds of red drum (Sciaenops ocellatus) fingerlings. Tolerance to low total dissolved solids (TDS) was measured by subjecting fingerlings to various test concentrations for 240 hours at 21° ± 1°C. Higher mortality in fresh water than in diluted sea water with similar TDS suggested that concentration of individual ions may be more important than TDS to survival of red drum in fresh water. Survival in solutions of increasing sodium chloride concentrations, but constant TDS, increased and was greater than 80% at chloride levels above 130 mg/liter. Tolerance to low temperature was measured by exposing fingerlings to different temperature regimes in fresh water adjusted to a concentration of 150 ± 5 mg/liter chloride. Lower lethal temperatures ranged from 3.0° to 0.8° C when water temperature was reduced 1° C per day.

Stress induced by handling, hauling, and net confinement was evaluated in 0.2-0.8-g red drum fingerlings (Sciaenops ocellatus). Changes in plasma glucose concentrations were used as general indicators of stress, and changes in plasma chloride concentrations were used as indicators of osmoregulatory dysfunction. Hematocrit dynamics were also monitored. Net confinement (for ≤ 9 hours) and transport (for ≤ 10.0 hours) caused elevated plasma chloride concentrations and decreased hematocrit. Changes in plasma glucose concentrations in net confined and hauled fish were not consistent. Fifty percent cumulative mortality was observed after 9 hours of net confinement. Almost no mortality occurred during transport. Fingerling red drum, subjected to short term stressors, such as standard hauling and stocking procedures, generally respond well, but some may die shortly after removal of the stressors.

Approximately 48% of 211 American eel, Anguilla rostrata, collected from brackish portions of Cooper River, South Carolina, were infested with 1 or more ectoparasitic species representing 2 classes, Monogenea and Crustacea. Seasonal and host size- and age-related variations in the levels of parasitism of Ergasilus cerastes and E. celestis were observed. These variations in levels of parasitism are discussed with a proposed life history for E. cerastes in southern waters.

Natural and induced production of striped bass hybrids was examined under controlled tank conditions. Four culture female F1 hybrid bass (striped bass, Morone saxatalis x white bass, M. chrysops) received human chorionic gonadotropin (HCG) and ovulated, but only 2 spawned eggs. These eggs, deposited in fresh water, were fertilized by HCG-treated cultured male F1 hybrids. One untreated (no HCG) female F1 hybrid which was paired with 2 untreated male F1 hybrids and held in brackish water (13 ppt salinity) also tank spawned and fertilized eggs were produced. This is the first documented case of a non-induced “natural” tank spawn among these striped bass hybrids. Hatch rates for the F1 x F1 hybrid cross were low. One attempt to induce a tank spawn between a HCG treated female white bass and 2 similarly treated male striped bass was not successful.

Population estimates were calculated for a known young-of-the-year (Y-O-Y) largemouth bass (Micropterus salmoides) population in a Piedmont North Carolina pond. Bass were collected by electrofishing for 6 consecutive nights. Estimates were derived using capture-recapture (Chapman, Chapman modified Peterson, Schnabel, and Schumacher-Eschmeyer) and removal (Leslie and DeLury) methods. Accuracy and bias of population estimates for each method were assessed from a statistical framework. All methods gave negatively biased estimates. Schumacher-Eschmeyer and DeLury exponential catchability models gave minimally-biased, accurate estimates within 12% to 17% of the true population. Independent Chapman estimates also gave acceptable results (known population within 95% confidence limits) when at least 56% of the known population was marked and the number of sampling occasions >4.

The U.S. Forest Service has been trying to improve the fish population structure of 120 flood control lakes and ponds in the National Forests of Mississippi and Louisiana. Recent efforts have included supplemental stocking, complete eradication of existing populations followed by restocking, and selective species eradication. Since 1978, 36 lakes, 25 ponds and 59 livestock and wildlife watering ponds varying in size from 0.1 to 940.5 ha have undergone fish population alteration. Fifty-three of these lakes and ponds were completely restocked, while 57 have received supplemental stocking. Preferred species combinations in restocking programs have been largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus) and redear sunfish (L. microlophus), and channel catfish (lctalurus punctatus) at rates of 20,200,20, and l2-45/ha respectively. Supplementally stocked species have been largemouth bass (M. salmoides), spotted bass (M. punctulatust, Florida bass (M.

As an evaluation of Oklahoma's Standardized Sampling Procedures (SSP), Lakes Arbuckle and Thunderbird were electrofished monthly from April through October 1983. Monthly largemouth bass (Micropterus salmoides) population structure indices and length frequencies were calculated from blocks of effort and increasing sample sizes. Reliability of estimates was determined by comparisons with values calculated from total monthly effort and catch. Spring and fall indices and length frequencies calculated from sample sizes of 150 bass or 5 hours of electrofishing effort were considered adequate to accurately reflect population structure.

A condenser cooling water (CCW) tap valve, a pump-net system, a fine mesh screen and a stationary net were used to measure larval fish entrainment at a power plant and were compared on the basis of relative efficiency, reliability, and cost. Mean densities of shad (Dorosoma sp.) collected were highest when using the CCW tap valve. Concurrent trawl samples indicated that mean densities in the pump-net and tap samples responded to changes in larval fish mean densities in the reservoir proximal to the plant intake. Overall, the CCW tap was determined to be the most efficient, reliable and cost effective method.