Journal of the Southeastern Association of Fish and Wildlife Agencies

A recreational fishery for semitropical reef fishes has developed over the past 12 years off the North Carolina and South Carolina coasts. About 30 headboats fishing from coastal cities transport anglers to the fishing grounds daily for a fee. The faster vessels regularly fish selected locations on the edge of the Continental Shelf 40 to 50 miles offshore while the slower ones fish coral patches and rocky outcroppings closer inshore. A large part of the catch is composed of four species of grouper: scamp, Mycteroperca phenax; gag, Myderoperca microlepis; speckled hind, Epinephelus drummondhayi; and snowy grouper, Epinephelus nil)catus. Catch and effort statistics indicak that these species can become quickly depleted from fishing sites hy continued heavy fishing pressure. Their alulndance on fishing sites in the area has generally remained high, however, because vessel captains try to spread fishing effort in order not to deplete anyone site.

Various aspects of the life history of spotted seatrout in Georgia were studied. Females comprised 63.2 per cent and males 36.8 per cent of all fish examined. Spotted seatrout moved from the shallow waters of the estuaries to deeper waters in the creeks and rivers during periods ofhigh and low water temperature. Spawning occurred in the shallow waters in all sectors of the eshlaries including the beaches near inlets. Food items found in the stomachs of spotted seatrout consisted of 53.9 per cent fish, 44.9 per cent shrimp and 0.8 per cent squid.

A total of 122,700 acres ofleased oyster bottoms were adversely affected by the flood waters of 1973; this represented 68 percent of the leased oyster grounds in Louisiana. Additionally, much orthe public natural "Oyster Seed Grounds" were subjected to unusually low salinities, siltation, and vegetation overburden; this resulted in loss of a portion of the 1973 seed oyster crop.

Blue crabs, Callinectes sapidus, stocked in cages at two different densities both with and without artificial habitats were compared for growth and survival in a power plant discharge canal and in a pond. Survival was higher for crabs in the pond but growth was significantly greater for those in the discharge canal. Artificial habitats increased survival of crabs cultured in the discharge canal but had no effect on those caged in the pond. In the laboratory no significant differences were found in weight, carapace width, or survival of crabs selected at random in regards to molting cycle and placed in individual molting chambers at 30 C and ambient temperatures (21-29 C). In 35 days the greatest increases in carapace width for individual crabs were 52, 33 and 14% for small, juvenile and sub-adult crabs, respectively. Crabs, all sizes pooled, molted earlier at 30 C than at ambient temperatures (22.2 vs 25.0 days to first molt).

Threadfin shad impingement at 13 Tennessee Valley Authority electric generating plants from August 1974 through July 1975 was analyzed to assess mortality resulting from low water temperature. Concurrent laboratory experiments were conducted to evaluate the ability of cold-stressed threadfin shad to avoid impingement. Temperatures of 12°C stressed fish in the laboratory, while those below HOC caused high impingement mortality. At 5 of12 fossil-fuel plants, 90 percent or more orthe annual threadfin impingement occurred when water temperatures were below lOoC. At four plants, impingement was not related to low temperatures. Impingement at the Browns Ferry Nuclear Plant generally coincided with low water temperatures, but individual impingement peaks were not consistently associated with cold shocks.

The fish population in the heated discharge channel from Colbert Steam Plant on the Tennessee River was sampled from January 1972 to December 1973 to determine the effects of temperature on species composition, relative abundance, and diversity. Electrofishing (108 samples) and gill netting (36 samples) yielded a total of 34 species; median number of species per sample for each type ofgear was nine. Species that were commonly colleded from the discharge channel at maximum summer temperatures (33-35 C) included: spotted gar, gizzard and threadfin shad, carp, billegill, longear sunfish, spotted bass, largemouth bass, and channel catfish. The occurrence of only three species (skipjack herring, sanger, and walleye) was considered temperature dependent; these species apparently avoided the heated efHuent at temperatures above 30 C. Mortalities resulting from temperature differences were not ohserved.

In the presence of a dense population of blue tilapia, the population of northern largemouth bass declined in three years to one-third its 1972 abundance in Trinidad Lake, Texas. A pond experiment with Florida largemouth bass indicated that bass failed to reproduce sllccessfully at a tilapia density of 2000 Ib/A, but at 1000 Ib/A some bass spawning occurred. Trends in gonosomatic indices suggest that eggs were retained by bass at high tilapia densities.

A method to determine short term muskellunge stocking mortality by using isolation coves is discussed. The method allows for free movement and feeding of muskellunge while restricting lakeward movement. Mortality of muskellunge was readily determined with the use of SCUBA. Stocking mortality due to stress of handling and transportation was considered minimal. Observations indicate that future stocking of muskellunge be made in areas of extensive weed cover.

An 11-year summary of fish disease case work at the Southeastern Cooperative Fish Disease Lahoratory is presented. A total of 1,573 cases were examined. Approximately 61 percent of these cases occurred in April through September with June having the greatest number. Viral cases, primarily channel catfish vims, were diagnosed from June through September. Bacterial organisms were diagnosed in 27 percent of the cases and were most prevalent from April through September. Aeromonas hydrophila or Flexibacter columnaris were involved in k2.2 percent of the hacterial cases. Parasitic cases were most prevalent in the spring and fall. Parasites were diagnosed in 25.2 percent of the cases. Of these, protozoa were involved in 59 percent with the dominant forms being; Ichthyophthirius and Trichodina.

To determine the extent of pond owner management and the condition of balance of the fish population during the first 2 years of fishing in small ponds, 40 ponds were randomly selected for study from ISO ponds 1.0 acre or less in size stocked in the 1971-72 stocking season. Only five ponds contained balanced Hsh populations both study years. Primary factors aHecting fish population balance were fertilization, livestock utilization, competitive species, severe water level reduction or complete loss of water, and fish kills. Proper pond management was not practiced by most pond owners in the study.

Channel catfish were stocked in 16 Alabama state-owned and managed public fishing lakes in an effort to create an additional sport fishery. The catfish harvest was generally low the first year after stocking with 100 catfish fingerlings per acre in an established bass-bluegillredear population. The harvest increased during the second year. The catfish harvest was 54.4 pounds per acre after the first year of fishing in a l00-acre public fishing lake in Alabama which was initially stocked with 100 channel catfish fingerlings per acre in addition to the nonnal stocking rate of bass, bluegill, and redear. White catfish did not appear to contribute as much to the overall catch as channel catfish under the conditions studied. Channel catfish were well received by the fishing public and contributed significantly to the overall catch in Alabama's public fishing lakes.

Astudy was made on the growth and survival rates, sex ratios, and vulnerability to angling ofthe green sunfish redear sunfish ( (G X R) hybrid as compared with its reciprocal cross and parental species. The G x R hybrid had the highest mean annual absolute growth rate while the redear sunfish 0 X green sunfish C; (R x G) hybrid had the highest mean annual relative growth rate. The G x R hyhrid generally had the highest mean annual survival rate, while the green sunfish had the lowest. The sex ratios were: G x R hybrids. 99% males; R x G hybrids. 88% males; green sunfish. 83% males; andredearsunfish. 45% males. TheG x Rbybrid. R x G hybrid. and green sunfish were more vulnerable to angling than the redear sunfish. Abundant F2 offspring were observed in the pond containing pairs of R X C hybrids, while no F2 offspring were observed in the pond containing pairs of G X R hybrids.

Six 0.10-acre (0.04 ha) hatchery ponds containing striped bass flngerlings were treated with Karmex herbicide in an effort to control filamentous algae composed mainly of the genera Pithophora and Spirogyra. Ponds treated were fertilized and aerated immediately alter application of Karmex. Shortly after treatment with Karmex, large mats of filamentous algae floated to the surface, decayed, and were broken into fragments by agitation from aerators. The fragments settled to the pond bottoms. Dissolved oxygen concentrations dropped rapidly for several days following treatment, but remained above critical levels and then increased slowly. After 11 to 13 days dissolved oxygen concentrations at sunrise were above 8.0 mg/1 and aeration was discontinued. Dense phytoplankton blooms, believed to be a result of both fertilization and release of nutrients tied up in the filamentolls algae, developed 13 to 17 days after treatment with Kannex, and prevented new growths of filamentolls algae.

The occurrence of cellulase enzyme activity was examined in the stomachs of Texas fishes representing 26 species. Comparison ofthe results obtained from enzyme studies with food habits indicated that the two were independent. A hypothesis that the presence of certain enzymes might be correlated with black peritoneum in fish (McAllister 1959) must be rejected with regard to cellulase based on the results of this study. Unlike a previous study (Stickney and Shumway 1974) in which cellulase activity within species was always either present or absent, seven species examined during the present study were found to exhibit intraspecific differences in cellulase activity. Suggestions for further studies aimed at clarifying the mechanisms of cellulase occurrence and its potential importance to cultured species of fishes are presented.

Remotely sensed data and ground truth data were collected simultaneously from 16 experimental ponds during 6 days in June and July, 1974. Color infrared images were taken with hand-held 35mm cameras from single engine aircraft. Numerical color values for pond color were obtained visually matching the pond color with a Munsell Color System chip which had a standardized numerical value assigned to it. Ground truth data involved the determination of 14 chemical, physical, and biological parameters. Regression analysis indicated a significant correlation (P<.01) existed only between total and inorganic solids and the Munsell Color System. There was evidence to suggest that the color-inorganic solid relationship was masked by the organic solids present.

An evaluation of stocking catchable rainbow trout, Salmo gairdneri, in a section of the Brazos River was made in 1972-73 to determine if trout stocking is an economically and recreationally justifiable fishery management technique in Texas. A creel survey to measure fishing pressure and harvest, gross annual expenditures, and net economic value of the fishery was made before and after trout introduction. Benefits, in terms of increased harvest and utilization, were found to be substantially higher than the cost of stocking catchable rainbow trout.

Chiekahominy Reservoir, Virginia, was treated with a mixture of herbicides diquat and endothall to control obnoxious growths of Egeria densa Planchon. Herbicides were undetectable in water by the 16th day after treatment. Herbicides accumulated in plant tissue at levels higher than those in the water. Only diquat accumulated in hydrosoils. Diquat levels in hydrosoils increased as levels in plants and water decreased. All diquat had dissipated from hydrosoils after two years. Neither herbicide concentrated in edible fish flesh. Aerial photographic monitoring revealed the amount of surface acreage and fishable shoreline was increased substantially following treatment. Weed regrowth was greater in shallow areas than in deeper areas after one year. Seventy-two percent of the anglers polled to determine the sportsmen's opinion of the weed control project believed that the treatment alleviated the weed problem and increased fishing and boating enjoyment.

Fisheries managers have long operated under the assumptions that time spent fishing (angler-days) or pounds or numbers of fish caught (maximum sustained yield) were accurate measures of fisheries output. However, many fisheries managers today advocate development of a multidimensional output measure which would incorporate social, aesthetic, and psychological factors. The present srndy was undertaken to delineate and determine the relative importance of 10 items affecting the quality of angling as perceived by Virginia fee-fishermen. A self-administered questionnaire employing a modified Likert scale was used to evaluate the 10 quality related items. A factor analysis was run which resulted in four factors relating to the quality of fee-fishing. The factors were (1) attractiveness ofthe fishing site, (2) amount of fishing, (3) satisfaction, and (4) improvements needed.

Spawning of striped bass in the Tar River was studied in 1975 and results were compared with a similar study done in 1965. Egg samples indicated a significant increase in spawning activity probably due in part to an increased population established by stocking. More favorable temperatures in 1975 also resulted in an extended period of peak spawning. The location of major spawning grounds based on egg samples was found to cover a 25 mile span of river between River Mile 60 and 85.

Recoveries of 189 redbreast sunfish (Lepornis auritus) tagged in Little River, North Carolina, indicated that this species is moderately mobile. Upstream movements predominated among fish recaptured within 60 days after their release in April and May. The extent ofmovement ofmales and females was about equaL On the basis ofmeasurements at release and recapture, average annual increase in size was 2.4 cm in total length and 48.0g in weight. The estimated annual harvest by sport fishermen was 14.7%.

Largemouth bass collected from selected Florida locations and stocked in hatchery ponds were studied for growth and catchability differences. Data indicates that some populations grow faster than others and that females grow faster than males. Experimental fishing data indicates that some populations show trends towards greater catchability, but no one population was shown significantly more catchable.

Concurrent with other life history investigations of black crappie, Pomoxis nigromaculatus (LeSeuer), in Lake Okeechobee, monthly examinations of stomach contents were made. Three food items--amphipods, oppossum shrimp, and fish--comprised the bulk of the diet. A change in diet occurred in early winter when the occurrence and numberoftendipeds dropped to a very low level, and again in late srping to early summerwhen tendipeds began to comprise a substantial portion ofthe diet. Data collected indicate tendipeds were primarily ingested as the pupae move toward the water surface and leave their cases rather than being picked from the bottom mud. Small black crappie (from 60 to about 240 millimeters) primarily utilized cntstaceans and insects as food items. Increasingly larger fish more frequently utilized fish as food.

During the winters of 1972-73 and 1973-74 an evaluation was made ofthe effectiveness ofthe leg-hold and killing type (Conibear) trap for taking fur animals in coastal Louisiana. The leg-hold trap caught significantly more nutria and raccoons than the Conibear trap. However, the killing type trap appeared to be more effective for taking muskrats in flooded marshes. Approximately 92 percent of the animals caught in the Conibear were killed by the trap, only 15.8 percent died in the leg-hold. Thirty percent ofthe nutria taken in the leg-hold trap were undersize and released. Survival of undersize nutria, held briefly in captivity, appeared good.

Habitat differences 9 years after planting of slash pine are compared for three levels of site disturbance in a north Florida flatwoods. Observed wildlife abundance is discussed in light of structural (quality, occurrence and stratification) and nutritional habitat differences. Where grasses and forbs were most productive (low site preparation intensity), ground arthropods, small mammals, herhivores, birds, and insectivores were most abundant. Increased site preparation accelerated pine overstory and shrub midstory development with greater foliage arthropad abundance. Rapid vegetation successional changes may prevent animal and plant populations other than transients from effectively utilizing intensive site prepared slash pine plantations. Growth and development of slash pine overstories was favored by intensive site preparation at the expense of understory wildlife habitat.

Measurement of the quality ofwildlife habitat is a necessity in planning and analyzing water resource projects. A methodology that provides a measure of habitat quality must consider the following factors: 1) the quantity of land uses, 2) the degree of interspersion of land uses, and 3) the condition of land management. A computerized methodology that considers each of these factors is provided for estimating habitat quality and evaluating: the impact of proposed water resource development alternatives. A computerized methodology is desirable because it reduces the computational effort, the likelihood of computational error, and the time required to evaluate a large number of proposed alternatives. The computer output includes the information required to assess the degree of mitigation required.