Journal of the Southeastern Association of Fish and Wildlife Agencies

Spot (Leiostomus xanthurus) comprised 35.9% of the 92,823 trawl-caught fish at 8 stations in the vicinity of a power plant on the Cape Fear River estuary, North Carolina. Monthly length frequency determinations of trawl-caught spot showed the major size mode progressed from about 4 to 10 cm from April 1975 to December 1975. The highest catches per unit of effort during the 2-year study were in the intake canal of the power plant. Of 982 spot tagged in the intake canal, 161 were returned and 9.4% of these were impinged on intake screens. The rate of impingement was highest for those released nearest to the intake structure and least for those released at greater distances.

A total of 230 otoliths was used for age and growth analysis of Spanish mackerel (Scomberomorus maculatus) in the northern Gulf of Mexico. Male fish in the sample ranged from ages 0 to 6, whercas females were 0 to 4 years old. Females exhibited faster growth than did males. Von Bertalanffy growth equations were: males L = 552( I - e -0'''''+ 16h,), and females L = 604(1 - e 04'" ")751). Growth equations from this study showed that both sexes grew at significantly slower rates than did Spanish mackerel in south Florida waters. Age-frequency distributions showed a differential pattern of mortality between the sexes from ages I through 4. Females showed a 50% decline in numbers bctween ages I and 2, whereas males exhibited a decline of 80% between ages 2 and 3. The differential growth and age specific mortality patterns imply that males and females entcr the fishery at different ages and that the fishery is contributing noticeably to total mortality.

A trawl shrimp cage I (TSC), which was a modification of the cod end of a conventional wingnet, was evaluated for its ability to reduce the bycatch associated with shrimping. The webbing of the cod end was stretched around a box-like aluminum frame. This prevented the webbing in the cod end from collapsing under the weight of water pressure and cod end contents, thus releasing undersized shrimp and finfish directly into water. The TSC was evaluated between 6 June 1985 and 13 August 1985 in the estuarine marshes of eastern Louisiana. A 6.4-m aluminum flat bottom boat was outfitted with a conventional wingnet on I side and wingnet rigged with the TSC on the other. Although the TSC caught less shrimp overall, it retained approximately the same number of the larger, more valued shrimp « I04/kg heads on) as the conventional wingnet. The TSC reduced the finfish catch by an average of 75%.

Relative survival rates for phase II (150- to 250-mm total length) striped bass hybrids (Morone saxatilis x M. chrysops) were 23, 200 and 137 times greater than phase 1 (30- to 45-mm total length) fish for the 1983, 1984 and 1985 year classes, respectively. Mean condition factors of phase I fish collected in the field were significantly higher than phase II fish for all 3 year classes. Mean total lengths of phase I fish were significantly greater than phase II fish for the 1983 year class and for the 1984 fish collected in the spring of 1986. However, 1985 phase II fish collected during the summer of 1986 were significantly larger than 1985 phase I fish. Phase II fish made up 35% and 48% of the estimated striped bass hybrid harvest during the 1984-85 and 1985-86 creel periods, respectively. Stocking of tagged phase II fish was a useful technique in evaluating fingerling survival.

The establishment of a striped bass (Morone saxatilis) fishery in Lake Wateree, South Carolina, did not detrimentally influence largemouth bass (Micropterus salmoides) growth, abundance, or condition. There was no evidence striped bass introduction altered the clupeid, primarily Dorosoma spp., or the Lepomis ,Ipp. prey base. An important fishery was added, however, to the reservoir. The authors suggest care in applying results to other less fertile, prey deficient reservoirs.

Fingerling Morone hybrids were stocked into Storm Creek Lake, Phillips County, Arkansas, to control a nuisance gizzard shad (Dorosoma cepedianum) population and diversify the sport fishery. The lake, a 169.7-ha shallow, warmwater impoundment, was stocked with 31,000 hybrids during a 4-year period (1982, 1984, 1985, and 1987). Growth during their first 3 years was rapid (age 1-325 mm; age 11-428 mm; age III-591 mm). Number of age IV fish (602 mm) declined over time. Due to high water temperatures, low dissolved oxygen levels, and shallow nature of the lake, hybrid populations were not concentrated in deep, aerated areas, but were dispersed in shallow coves over the entire lake during summer and fall. Observation of hybrid stomach contents indicated use of shad (Dorosoma spp.) ranging in size from 178 to 229 mm. Population levels of young of the year and adult largemouth bass (Micropterus salmoides) were not affected by the introduction of Morone hybrids.

Eggs of striped bass and white bass were subjected to hydrostatic pressures of 5,000, 6,000, 7,000, and 8,000 PSI for a duration of 5 minutes (2.5 minutes for 8,000 PSI) at 29, 45, or 55 minutes after fertilization. The most effective pressures for producing tetraploidy in white bass were 5,000 and 6,000 PSI and for striped bass 7,000 and 8,000 PSI. Late in the spawning season, only 45- and 55-minute treatments were effective for producing tetraploidy. The relative hatch of eggs subjected to hydrostatic pressure for tetraploid induction was 55% of controls. Original and reciprocal striped bass x white bass hybrid eggs were subjected to hydrostatic pressures of 6,000, 7,000, and 8,000 PSI, applied 2 to 7 minutes after fertilization for durations of 2 to 5 minutes. Several treatments produced triploids; however, 8,000 PSI was the most effective pressure (50% triploid induction) when initiated 2 or 7 minutes after fertilization for a duration of 3 to 5 minutes.

Mortality of striped bass <20 inches total length (50.8 cm) captured by hook and line was investigated. Both artificial lures and baits were used with single and treble hooks. A control group of fish was captured by electrofishing and handled in a similar fashion. Fish (N = 683) were caught from a freshwater river and a small reservoir during 4 different months of the year (October, February, June, and August). After capture, test fish were transported to holding ponds and held 2 weeks to evaluate total (pre- and post-release) mortality. No fish died prior to release in the holding facilities. There were no significant differences in mortality between any of the groups comparing month and method of capture. Likewise, there were no significant monthly differences between treatments. There were significant differences within treatments for different months when compared separately.

Differences in growth rates between sexes were compared for Florida largemouth bass (Micropterus salmoides floridanus) from 5 north-central Florida lakes using lengths back-calculated for the most recently formed annulus on otoliths. Growing rates of Ages 1-6 fish differed between sexes in all lakes. Males were larger than females before Age 1 in 3 of the 5 populations, but by Age 2 females were larger than males in all lakes. Female fish were larger than male fish of the same age when the females attained total lengths of from 243 to 292 mm. Based on the samples collected, female Florida largemouth bass lived longer and attained larger sizes than males. Similar trends have been shown for several populations of northern largemouth bass (M. s. salmoides) and for comparisons of the growth rates of the 2 largemouth bass subspecies. We recommend consideration of sex differences in evaluations of growth rate of Florida largemouth bass.

Stomach contents of flathead catfish (Pylodictis olivaris) from the Flint River, Georgia, were examined to gain information on basic life history of this introduced species and to assess potential impacts on traditional fisheries. Acrylic tubes and a flexible claw retriever were effective for observing and collecting stomach contents which were then analyzed by frequency of occurrence, percent composition by number, and percent composition by weight. Young-of-the-year catfish contained primarily aquatic insects and began eating crayfish, sunfish (Lepomis sp.) fry, and darters (Etheostoma sp.) toward the end of their first year. Crayfish were the dominant food item by number and weight in flathead catfish shorter than 600 mrn. Flathead catfish, unidentified fish, and channel catfish were the primary teleost food items by weight in fish 301 to 600 mm in length.

Food habits of flathead catfish (Pylodictis olivaris) in the Cape Fear River were determined through analysis of 184 stomachs collected during the spring and summer of 1986. Fish were collected with a 5-bar, hand-cranked telephone generator (magneto). The objective was to determine if frequency of occurrence and percent by numbers of individual food items in the diet of flathead catfish changed significantly between 1979 and 1986. Current data indicate ictalurids, clupeids, and centrarchids remain the primary food items in the diet of Cape Fear River flathead catfish; however, a shift from ictalurids to clupeids as the primary food item occurred between 1979 and 1986. Centrarchids occurred with equal frequency in flathead catfish stomachs during 1979 and 1986 but were less numerous in the 1986 samples. There is no evidence to support anglers> claims that flathead catfish may be responsible for the reputed decline in sunfish populations within the river.

Food selection of 209 alligator gar (Lepisosteus spatula) and 165 longnose gar (L. osseus) in Sam Rayburn Reservoir, Texas, was examined. Gar were collected with gill nets and jug lines during September and October 1986. Alligator gar were selective, primarily for bottom dwelling fishes, but not to as great an extent as longnose gar. Longnose gar selected small prey, primarily threadfin shad (Dorosoma petenense). Both species will apparently shift to different prey depending on the species available.

Ninety-eight thousand walleye (Stizostedion vitreum vitreum) x sauger (S. canadense) hybrid (saugeye) fingerlings were stocked in Thunderbird Reservoir, Oklahoma, in May 1985, and 129,400 fingerlings were introduced in April 1986 to evaluate the possibilities of a superior put, grow, and take fishery where previous walleye fry stockings have failed. Saugeye showed rapid growth rates; age-0 fish attained a mean length of 270.8 ± 8.2 mm (mean ± 95% CL) by October 1985, and 256.1 ± 11.2 mm by October 1986. Both year classes preferred inland silversides (Menidia beryllina) as a forage species, with 75% of the stomachs sampled containing inland silversides. Although ≤200 mm largemouth bass (Micropterus salmoides) also utilize inland silversides, they do so only during periods when other forage species are limited. Therefore, competitive interaction during saugeye early life history is not suspected.

Within-bank disposal of dredged material has detrimentally impacted natural habitats and gamefish of the Apalachicola River. Between 1947 and 1980 40 km of natural bank habitat has been altered by disposal of dredged material resulting from navigational maintenance activities by the U.S. Army Corps of Engineers. Gamefish catch per unit of effort (CPUE) values from natural bank habitats were significantly greater (P < .05) than those from "new," "recent," and "old" disposal sites. Gamefish CPUE values measured on "new," "recent," and "old" disposal sites were 75%,66%, and 50% less than gamefish CPUE values on natural bank habitats.

Parasite loads of 4 larval fish species in a lower Mississippi River overflow pond were compared. Differences in parasite loads appeared to be related to adult spawning locations and larval fish habitat preferences. Allacanthochasmus sp. was the only parasite found in larval fishes, with maximum infestations of I metacercarial cyst in bluegill and 2 cysts in shad and inland silverside. No parasitism was observed in crappie. Total percent parasitism was highest in silverside (mean ± SE, 2.2 ± 0.5%), followed by bluegill (0.9 ± 0.2%) and shad (0.9 ± 0.3%). Results indicated that adult reproductive tactics, larval fish habitat preferences, and cercarial development of Allacanthochasmus sp. may influence rates of parasitism in larval fishes.

Relationships between fish abundance and diversity and stream pH and alkalinity were assessed to evaluate potential impacts of acidic precipitation on fish assemblages of southern Appalachian Mountain headwater streams. Data were obtained from first- and third-order reaches of 12 stream systems during spring and fall 1983 and spring 1984. Assemblages exhibited low diversity and typically had low biomass. All streams were slightly acidic (mean pH = 6.62; range 6.25-7.00) and very poorly buffered (mean total alkalinity = 58 /µeq/liter; range 16-33), indicating extreme chemical sensitivity to acidification. However, statistically significant relationships between fish biomass or diversity and stream sensitivity were not consistently detected. The absence of such relationships suggests that acidification probably has not had a substantial impact on fish populations in headwater streams of the southern Appalachian Mountains.

Channel catfish (lctalurus punctatus) were obtained from 3 lakes in southeastern Louisiana during the fall of 1986. A truss network of morphological measurements was developed, resulting in 10 variables measured on each individual fish. Morphological variables were adjusted to remove the effect of standard length through least-squares regression. Multivariate analysis of variance of adjusted variables yielded significant (P < 0.01) differences among lakes. Factor analysis of the partial correlation matrix of adjusted variables yielded 4 non-orthogonal dimensions descriptive of body shape variation, interpretable as: I) overall depth of body, 2) length of posterior portion of body, 3) caudal peduncle depth and location of anal and adipose fin insertions, and 4) location of dorsal fin insertion. Univariate analysis of factor scores showed significant (P < 0.05) differences among lake populations only on the first factor.

Stress due to confinement in a net caused higher mortalities in largemouth bass Micropterus salmoides salmoides which were extensively-reared in ponds on zooplankton and other invertebrates than in those which were intensively-reared in raceways on pelleted food. Fish that were intensively-reared weighed more than the fish reared in ponds, although both groups were sorted with the same bar-grader. Intensively-reared fish exhibited 3% and 9% mortalities after 13- and 16-hour net confinements, respectively, compared to 34% and 38% for those fish reared in ponds. Fish reared intensively may be better able to tolerate the stress of harvest, handling, and transportation than extensively-reared fish.

The effectiveness of a catch-and-release regulation for largemouth bass (Mieropterus salmoides) was assessed from 1982 to 1987 at Webb Lake, Florida. The objective was to prevent rapid overharvest of bass and maintain high angler success rates in this new 158-ha lake. Prior to opening the lake to public fishing, experimental angling for largemouth bass resulted in catch rates (C/E) averaging 3.3 fish/ hour. During 30 months of public fishing, the average C/E dropped to 1.3 fish/hour. Decreases in largemouth bass biomass estimates, population density, and proportional stock density indicated that the largemouth bass population experienced high angling mortality during the first 6 months of public fishing. Few documented incidents of angler noncompliance were reported; however, it is possible that even low levels of illegal harvest, combined with hooking mortality, caused this decline.

A Delphi exercise conducted on sauger (Stizostedion canadense) with a panel of 17 experts resulted in II habitat suitability index curves that associate various life stages or activities of sauger with 5 variables: velocity, depth, substrate type, temperature, and cover. The curves are preliminary but should be useful for assessing habitat suitability for sauger until empirical curves are developed and for focusing future research and information exchange.

The Florida Game and Fresh Water Fish Commission conducted a telephone survey of 602 licensed resident fresh water anglers to assess the effectiveness of agency programs and delineate future direction. Over 70% of license holders were primarily largemouth bass fishermen. Licensed anglers have a higher socioeconomic status than the general public. At least 60% of licensed bass anglers support restrictive regulations to improve bass fishing. Presented with 6 major fisheries programs, more licensed anglers felt lake restoration and largemouth bass management (37% and 22%, respectively) should receive primary emphasis. Of 10 fisheries research or management initiatives, only 2 were known to 50% or more of licensed anglers. Thirty percent of licensed anglers felt television and newspapers should be used more often to communicate fisheries information, and 18% felt more brochures should be used.

An on-site interview and mail questionnaire survey of 409 anglers on the Shenandoah River, Virginia, was conducted to compare the characteristics, motivations, perceptions, and preferences of anglers fishing under 3 different minimum black bass length limit regulations (no size limit, a 279-330 mm slot length limit, and a 305 mm minimum limit). Considerable uniformity was found in the 3 regulation areas in harvest behavior, equipment expenditures, perceptions of fish quality (size), components of fishing enjoyment, motivations for fishing, and fisheries management and regulation preferences among anglers regardless of length limit regulations. Anglers in the 3 length regulation zones differed significantly only in their trip expenses, travel distances, catch and harvest rates, knowledge of existing regulations, and preferred length limits.

A stocked rainbow trout (Salmo gairdneri) fishery in newly impounded Tellico Reservoir, Tennessee, was evaluated through creel surveys. In 1980, the first year of impoundment, trout made up 41.1% by weight of all fish harvested declining to a mean of 9.8% over the next 4 years. Estimated annual effort for trout averaged 53,000 hours. Rainbow trout catch rate averaged 0.067 fish per hour, and the harvest return of stocked rainbow trout averaged around 69% by weight over the 5-year period. Average catch per hour was lower than observed from other southeastern, 2-story trout fisheries. Insects comprised the primary food source and fish were second, based on percent total weight of food items ingested. Coefficients of condition indicated that the upper reservoir area was superior to the lower reservoir as trout habitat during spring and summer, apparently due to cool water releases of an upstream reservoir.

The effect of body size on the temporal spawning sequence of female largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus), and gizzard shad (Dorosoma cepedianum) was examined in 2 Mississippi reservoirs by monitoring gonadal development through portions of the spawning seasons. Largemouth bass began spawning in late March when water temperature was near 15° C, gizzard shad in about mid-April at temperatures nearing 17° C, and bluegill in late April when temperatures reached 21° C; however, spawning seasons of the 3 species overlapped. Ovarian activity of largemouth bass and gizzard shad suggest strongly that the larger females spawned earlier than smaller ones, but the evidence in bluegill was weaker. Considering that the spawning season of the bass and 2 prey species overlapped, the bass that were spawned earliest and parented by the largest females in the population were larger and more likely to begin eating shad and bluegill earlier in life.