Journal of the Southeastern Association of Fish and Wildlife Agencies

Infonnation from applications to 2 angler recognition programs administered by the Texas Parks and Wildlife Department were analyzed to determine changes in the number and weight of fish submitted each year. Frequent increases in largemouth bass (Micropterus salmoides) (5 in a 6-year time span), striped bass (Morone saxatilis) (9 in a 14-year time span), and hybrid striped bass (M. chrysops X M. saxatilis) (7 in 8-year time span) state records were documented. Significant annual increases in mean weight of largemouth bass (4.0 kg in 1974 to >5.0 kg in 1986 and 1987) and smallmouth bass (M. dolomieui) (2.16 kg in 1979 to 2.63 kg in 1987) certified for Big Fish Awards were recorded. Increases in size of largemouth bass and striped bass certified were directly related to stocking programs.

A survey was conducted of landowners on upper Lake of the Ozarks, from the Harry S Truman Darn at Warsaw, Missouri, to 16 miles below the darn. The study was initiated to determine citizen opinion toward the current 4-turbine operation at Harry S Truman Darn in light of managing authorities' proposals to increase power generation through routine use of 2 additional turbines that could diminish recreation and tourism values of upper Lake of the Ozarks. Results revealed that landowners residing at the lake had little tolerance for any changes in hydropower operations that would increase water fluctuations, bank erosion, and siltation at the lake. Generally, property owners indicated that fishing, swimming, and boating on the lake had worsened since the darn began generating power in 1981, but the quality of these recreational activities still was acceptable under prevailing management.

We conducted tests to quantify delayed mortality of white crappie (Pomoxis annularis) after catch and release by anglers. White crappie were subjected to I) catch and release in shallow water using traditional hook-and-line methods and 2) rapid depressurization to simulate catch in deep water. Mortality 6-11 days after catch and release from shallow water averaged 3%. No significant differences (P > 0.05) were detected between mortality rates of white crappie 15-25 cm and >25 cm total length, nor between fish caught using live and artificial baits. No mortalities occurred 96 hours after white crappie were depressurized from depths ≤10m, but 29% and 67% of the fish died when depressurized from 13 and 16 m, respectively. Regulations involving catch and immediate release of white crappie can reduce fishing mortality, but may be less effective when and where fish are frequently caught from deep water.

The commercial trotline fishery on the Kentucky portions of Kentucky Lake and Lake Barkley was evaluated by a telephone survey, an onboard survey, and from market data. Results indicate that the telephone survey was a reliable source of economic information based on high correlations (r ≥ 0.89) of effort and harvest data among the 3 data sets. Data obtained from the onboard survey overestimated economic impact of the fishery because of bias toward full-time fishermen. However, the onboard survey did yield accurate species composition information. Thirty-five percent of the respondents in the telephone survey were full-time fishermen, 44% were part-time, and 21% fished for non-profit reasons. Although the annual estimated harvest in the trotline fishery (745,500 kg) was valued at $0.8 million, fishermen reported an income of $1.5 million, nearly twice the value of their harvest. Ninety-seven percent of total catch (both kept and released) and harvest, by weight, was catfish.

Low altitude aerial surveys were conducted at approximately monthly intervals from I April 1987 to 31 March 1988 to determine temporal and geographic distribution of commercial fishing in Texas bay and Gulf (Texas Territorial Sea) areas. Observers counted a total of 4,841 bay commercial vessels and 1,906 Gulf commercial vessels conducting 7 types of fishing activities over the 12-month study period. Commercial shrimping made up 87.7% of all commercial activity. Most activity was observed between May and November. Thirty-nine percent of the bay commercial activity was concentrated in Galveston Bay while 27% was in Matagorda Bay. San Antonio, Aransas, and Corpus Christi bay systems collectively yielded 29% of the commercial bay vessel counts. Gulf commercial shrimping was evenly distributed along the entire coast with a slightly higher concentration around the Galveston offshore area. Photography and ground counts were assessed as verification to observer counts.

A major concern in managing commercial fisheries is the potential effect on game fish populations. The objective of this study was to design a model to determine annual game fish bycatch in hoop nets, wire traps, and pound nets utilized in the 51. Johns River, Florida, commercial catfish fishery. Annual bycatch was estimated with a model based on previous estimates of annual catfish harvest, catfish-to-game fish ratios, mean weight of catfish harvested and percentage composition of catfish harvested by each gear type. Hoop nets captured an estimated 435,635 game fish annually with 46,697 and 7,589 game fish captured annually by wire traps and pound nets, respectively. When catches of all 3 gear types were combined, black crappie Pomoxis nigromaculatus comprised 54.5% by number of all game fish caught, followed by Lepomis spp. (44.4%), Morone spp. (0.7%), largemouth bass Micropterus salmoides (0.4%), and chain pickerel Esox niger (0.01%).

Juvenile spotted seatrout Cynoscion nebulosus (48-73 mm TL) and snook Centropomis undecimalis (43-63 nun TL) were subjected to 35- and 42-day growth trials, respectively, at 5 different temperatures. Respective test temperatures were 11.5°, 15.5°,22.0°,28.0°, and 32.0° C, and ISS, 21.0°, 28.0°, 32.0°, and 37.0°C. Salinity was 20% for both trials. Optimum temperature for growth of both species apparently occurs at ≥28.0° C. Spotted seatrout specific growth rate (2.39%) and mean total length (TL) (78 mm) was greatest at 28.0° C, while specific growth rate (0.54%) and mean TL (67 mm) at lIS C was less than at all other temperatures. Specific growth rate of juvenile snook at 37.0°, 32.0°, and 28.0° C (1.20%, 1.46%, and 0.93%, respectively) was significantly greater than growth at 21.0° and 15.5° C (0.31% and -0.15% respectively). Snook mean TL at trial conclusion was greatest at 32.0° C (62 mm) and least at 15.5° C (52 mm).

South Carolina and Texas red drum (Sciaenops ocellatus) fingerlings were compared to evaluate pond overwintering characteristics. Red drum from each hatchery stock were spawned in September 1987 and fry were reared in outdoor earthen ponds. Red drum fingerlings (mean ± SD total length (TL) South Carolina fish 50.5 ± 4.9 mm; Texas fish 48.3 ± 4.4 mm) were transferred to 6 0.2-ha saltwater ponds in November 1987, and ponds were harvested in March 1988. The lowest water temperature encountered was 3.00 C on 10 January 1988. Survival was similar between Texas (91.7% ± 13.9%) and South Carolina (83.5% ± 6.6%) fingerlings. Production (kg/halday) was also similar between the 2 stocks. Fish grew at equal rates over the production period; at harvest, mean TL of South Carolina fish was 87.7 ± 11.9 mm, TL of Texas fish was 83.7 ± 11.2 mm.

Phase-l hybrid striped bass fry were fed trout pellets at 0,6.7, and 13.4 kg/haJday, in 7 culture ponds in 1986. Yield ranged from 45.6 to 239.7 kg/ha. Survival ranged from 11% to 70%. Five ponds in which fish were fed trout pellets had substantially greater yields of hybrid striped bass fingerlings than 1 pond in which fish were unfed. In 1987, two culture ponds in which fish were fed trout pellets at 13.4 kg/haJday from the time of initial stocking had significantly greater (P < 0.05) yields of hybrid striped bass fry than 2 ponds initially fed 18 days after stocking. Yields ranged from 0 to 86 kg/ha and survival ranged from 0% to 61%. Feed allotment and time of initial feeding of trout pellets affected production of hybrid striped bass.

The growth in weight of hybrids of striped bass (Morone saxatilis x white bass M. chrysops) fed trout pellets was compared to that of hybrids fed redbelly tilapia (Tilapia zilli, the latter of which were starved to reduce lipid content or were well-fed to ensure greater lipid levels. Production did not differ significantly between fish that ate starved tilapia and those that ate trout pellets. Growth was significantly greater, however, in hybrids that ate fed tilapia than in those that ate starved tilapia. The nutritional value of the pelletized ration was inferior to that of well-fed tilapia, indicating the need for improvements in diet formulation.

Paddlefish (Polyodon spathula) larvae were fed live cultured Daphnia at 4 densities to determine if larval survival and growth were affected by Daphnia densities at low (ambient) (15.0° ± 1.5° C) and high (21.1° ± 0.5° C) temperatures. Survival of larvae increased with increasing densities of Daphnia in both experiments. Survival was higher in the low-temperature experiment than in the high-temperature experiment. However, larval survival was also influenced by cannibalism and a deformity affecting swimming behavior. Maximum growth of larvae during the 7-day experiments was 23.2 mm in length and 88.0 mg in weight and was determined graphically at Daphnia densities ranging from 200 to 240/liter in the high-temperature experiment. Short-term intensive culture of paddlefish larvae fed live Daphnia appears to be a viable method for producing large, hardy fish for further grow-out in ponds.

Adult channel catfish (Ictalurus punctatus) and flathead catfish (Pylodictis olivaris) monitored by radiotelemetry made frequent movements within Perche Creek, a tributary of the lower Missouri River. Individuals of both species moved at a rate greater than 50 m/day in >50% of all observations. The favored depth for both species was 1 - 2 m, even though shallower and deeper habitats were available. Both species avoided open water habitat and selected complex woody structure over other cover types. Channel catfish movements were more restricted in Hinkson Creek, an upland tributary of Perche Creek, where habitats > 1.5 m deep were rare. Catfish in Hinkson Creek selected the few deep pools available and favored cover types similar to those selected in Perche Creek. Channel catfish in Perche Creek tended to move to the Missouri River, but flathead catfish tended to remain in Perche Creek, even though these 2 species were equally mobile within Perche Creek.

Small diameter hoop nets were compared with low frequency, pulsed DC electrofishing for assessing flathead catfish (Pylodictis olivaris) stocks in the Noxubee River, a small stream in east-central Mississippi. Small diameter hoop nets fished during summer low flow regimes were appropriate for collecting stock size fish (≥280 mm, total length) while electrofishing was a better tool for assessing smaller flathead catfish. No significant difference (P >0.05) was found between the 2 sample techniques with regard to kg/man-day or fish/man-day. Small diameter hoop nets were determined to be the most appropriate gear for sampling flathead catfish resources in streams where the use of boats is restricted by poor access.

Isoelectric focusing (IEF) and densitometric scanning were used to identify 6 species of catfish based on diagnostic bands and banding patterns produced by muscle proteins. Blue catfish (lctalurus furcatus), white catfish (Ictalurus catus), and flathead catfish (Pylodictis olivaris) each have diagnostic bands in pH 4-5 gels that allow positive species identification. IEF of channel catfish (Ictalurus punctatus) musculature in this pH range exhibits a polymorphic system. One of the bands is diagnostic for this species when present, allowing identification of 58% of the channel catfish tested. Channel catfish without this band, yellow bullhead catfish (lctalurus natalis), and black bullhead catfish (Ictalurus melas) are indistinguishable in the pH 4-5 range gels, but can be identified by banding patterns produced by IEF of proteins in pH 6-7 gels.

Increased management of wild catfish stocks is imminent due to their growing popularity with anglers and commercial exploitation. Length-categorization systems, like those used for largemouth bass (Micropterus salmoides), would improve catfish stock assessment and facilitate comparison of results among years, gears, samples, and populations. Flathead catfish (Pylodictis olivaris) from the Flint River, Georgia, collected by electrofishing and those caught by fishermen were assessed with Proportional Stock Density (PSD) and Relative Stock Density (RSD) indices. Population PSD was 72, suggesting a high quality fishery. Fishermen selected fish in the RSD Quality-Preferred and Preferred-Memorable length categories. Minimum length for size categories may be too low, and I submit alternate thresholds. Use of a standardized system is recommended for reporting results of catfish studies.

We conducted laboratory and field investigations to detennine the relative value of shads (Dorosoma spp.) and sunfishes (Lepomis spp.) as prey for largemouth bass (Micropterus salmoides). In the laboratory, we examined the energy content of gizzard shad (D. cepedianum) and bluegill (L. macrochirus) and digestibility by largemouth bass. Although the ratios of proximate components in the 2 prey species differed, total energy contents as calories per gram were equal. The rates at which gizzard shad and bluegill were digested were similar at feeding rates <1.5%-2.0% of largemouth bass body weight, but gizzard shad were digested increasingly faster than bluegill at progressively higher feeding rates: maximum rate of digestion occurred at about 5% of the largemouth bass body weight for gizzard shad, and about 3% for bluegill.

We measured effects of an increase in the largemouth bass minimum length limit from 254-mm to 406-mm and a decrease in the creel limit from 10 per day to 3 per day in Tradinghouse Creek Reservoir, Texas, from 1985 to 1987. Electrofishing and rotenone surveys were used to measure regulation effects on largemouth bass population and predator-prey parameters; angler surveys were used to determine effects on creel rates. After the regulation was implemented, the population structure shifted from one dominated by small, young individuals to one dominated by larger, older fish. Although relative weight among stock-quality and quality length groups declined, growth rates remained stable. Estimates of available prey remained below optimum levels. Angler catch rates increased 89%; harvest rates declined 70%.

The minimum legal size of largemouth bass (Micropterus salmoides) was increased from 305 to 406 mm in 1983 on West Point Reservoir to indirectly increase young-of-the-year recruitment by gizzard shad (Dorsoma cepedianum). Fish collections from 1982 through 1987 indicated that largemouth bass increased in abundance in response to the regulation change and their population structure shifted toward larger sizes. Concurrently, gizzard shad size distribution shifted downward. It appeared that the increased size limit for largemouth bass resulted in increased forage through increased gizzard shad recruitment. A survey of the sport fishery in 1984 and 1985 indicated effort and harvest similar to that before the regulation change.

Populations of largemouth bass (Micropterus salmoides) in Oklahoma reservoirs were sampled in 1986 and 1987 to determine the degree of introgression of Florida largemouth bass (M. s. floridanus), introduced over a 16-year period, into populations of native northern largemouth bass (M. s. salmoides). Florida subspecific alleles were present in 28 of 30 populations (93%) and were found in >50% of the fish from 8 (27%) reservoirs. Correlations with selected physical and biological parameters indicated that the percentage of bass with Florida alleles increased as the size of fish stocked increased and as cold weather and water level fluctuation decreased. Reservoirs in southern portions of the state with stable water levels that were stocked with fingerlings > 100 mm in length at rates > 25/ha for several consecutive years had the highest degrees of Florida allele introgression into existing bass populations.

Twenty-seven comparison tows were made between a 2-seam otter trawl with 6 loops of 13 link, 4.8-mm chain attached to the leadline (original net) and an identical trawl with additional chain loops attached every 25.4 cm across the entire leadline (heavily chained net) during June-August 1988 in tributaries of the Neuse River, N.C. Objectives were to determine the effect of the heavily chained net on the juvenile finfish, crab, and shrimp catch-per-unit-effort (CPUE) estimates and the feasibility of developing conversion factors to convert CPUE estimates from one net type to the other. The CPUE estimates were significantly higher (P ≤ 0.01) with the heavily chained net for juvenile Atlantic croaker (Micropogonias undulatus), southern flounder (Paralichthys lethostigma), and blue crab (Callinectes sapidus).

The effects of soak time and fish density on number and size of white crappie (Pomoxis annularis) caught with trap nets were investigated in Mississippi lakes. Catch/set (1-7 days) of large white crappie (≥200-mm total length) increased asymptotically with soak time, but that of small and medium fish (<130 and 130-199 mm, respectively) decreased after the first 2-3 days. Catch/day of all length groups of white crappie, increased sharply with soak time, peaked in 1-3 days, and decreased thereafter. These trends indicated that catch could be optimized if nets were run every 2-3 days, and that longer soak times could result in the underestimation of small and medium-size fish. Trap net samples taken within 0.4- to 2.4-ha lake enclosures prior to treatment with rotenone indicated that catch/effort in nets reflected absolute abundance of medium and large white crappie within these areas.

Fisheries personnel of the Arkansas Game and Fish Commission have developed a standardized system of collecting, analyzing, and reporting electrofishing and rotenone sample data. The system utilizes microcomputers and custom written Microsoft QuickBasic Version 4.0 programs and dBASE files to compile sample data, generate reports, and store information in a statewide database. This system provides fish managers with a quick method for processing data with in-depth analysis while relieving them of time consuming manual processing of sample data. Processing of data is performed by a centralized computer staff for storage in a statewide database that is easily accessed by non-programmers.

Larval fathead minnows (Pimephales promelas), <48 hours old, were exposed to water from the Apalachicola, Choctawhatchee, and Ochlockonee rivers in northern Florida during field toxicity tests in November 1985 and April 1986. The fish were exposed for 6 or 7 days in a flow-through system to control water; full-strength river water; and 50%, 25%, and 12.5% dilutions of river water. Mortality in full-strength Choctawhatchee River water was significantly higher (40% mortality) than in control water or in the 3 other dilutions of the river water (<15% mortality). Mortalities of fathead minnows in the different dilutions of the Apalachicola and Ochlockonee rivers did not differ significantly from those in the controls. Further study is needed to determine the cause of the toxicity of Choctawhatchee River water to larval fish.

Growth of introduced Stizostedion hybrids (S. vitreum x S. canadense) was examined from July 1983 to December 1985. Hybrids averaged 296 and 442 mm TL at ages 1 and 11. Condition factors (K) of hybrids increased with age, while relative weights (W,) were within the acceptable range (95-105) for all but 3 months of the first 2 years following introduction. Both condition indices decreased sharply during the spring and early summer. Reduced abundance of small shad due to winter mortality and altered predator-prey relationships during spring and early summer may seasonally impact condition of hybrid Stizostedion.

A telemetry study was conducted in the Apalachicola River/estuary, Florida, to determine migratory behavior of anadromous Gulf of Mexico sturgeon. Ultrasonic (remote and mobile units) and radio telemetry gears were used to assess movements of sturgeon in both fresh and saltwater. Transmitter-equipped fish (N = 10) began fall migration between 22 September and 19 October 1987, and averaged 4.6 days to descend 152 Ian to the lower Apalachicola River where freshwater "staging areas" were utilized for periods of 0-20 days prior to moving into brackish river water. Three sturgeon continuously monitored during river exit spent 8-12 hours in brackish river water, apparently osmoregulating before making nocturnal exits to Apalachicola Bay. Ultrasonic monitoring was largely unsuccessful, although 3 sturgeon were tracked into saltwater and monitored in Apalachicola Bay for up to 4 hours.