Journal of the Southeastern Association of Fish and Wildlife Agencies

In 1964, five sections of the Shenandoah River ranging from 9.0 miles to 15.3 miles in length (average 11.4 miles) were selected for an airplane census of fishermen. The census was conducted on a randomized schedule2 for both days of the week and time of day for the counts, with weekend days weighted because of heavier fishing pressure on those days. These data for 1964 through 1967 were used to compute the total fishing pressure in these sections. Creel clerks were employed on a part-time basis in each of the five sections to gather information on the number of smallmouth bass, both undersize and legal size, as well as the number and sizes of channel catfish, sunfish, and other species caught. The number of hours each fisherman fished were also recorded. In three of the sections, mail boxes with measuring boards at hand were supplied at boat landings, or other points of access, so that voluntary reports could also be supplied by anglers.

The effects of supplemental feeding and controlled fishing in sUPPlementally fed largemouth bass-bluegill populations were studied in one control pond and two treatment ponds. The ponds were stocked in March and April, 1963. One treatment and the control pond were drained in October, 1964. The objective of this phase of the study was to determine the effects of supplemental feeding on growth rate, condition index, and survival of bluegill, and on population balance and total production. A second phase of the experiment, restricting the harvest in a given time interval on a 3.5-acre pond, was begun in 1964 and terminated in October, 1967. Bluegill in all ponds grew at comparable rates for the first 6 months after stocking. Seven months after stocking, bluegill in the treatment ponds were significantly heavier than those in the control pond.

A cooperative fishery survey of the terminal 33 miles of the Little Tennessee River, a tailwater environment, was made using an unequal probability sampling creel census and limited population sampling. From June 1964 to June 1965, 29,349 anglers caught 64,714 fish at a rate of 0.75 fish per-angler-hour, or 2.2 fish per-angler-day. Of all anglers, 56% were successful, 91% lived within 40 miles of the stream, and the average expense per-trip was $2.41. The catch was 70.5% trout, 16.3% sauger, and 13.2% other species. All trout and 83% of all fish were caught in the upper half (14 miles) of the river. The catch in the lower half was 80% sauger. Various sizes and species of marked trout were stocked at different times to determine best management methods. Returns from catchable-sized brown trout were slow but extended. Catchable rainbow returns ranged from 78 to 96%. Early spring stocking gave best distribution of fish to more anglers.

Marking is accomplished by embedding fluorescent pigment into the dermal tissue of fish with compressed air. The principal species evaluated were largemouth bass, Micropterus salmoides, bluegill, Lepomis macrochirus, redear sunfish, Lepomis microhophus, and channel catfish, Ictalurus punctatus. Marking rate was approximately 1500-2000 fingerling size fish per hour with a two-".,'m team. Mark detection requires ultraviolet light. Air pressure and application distance are critical factors in marking success. Best results were obtained using an air pressure range of 85-200 psi from a distance of 12 to 18 inches. After 9 months mark retention on largemouth bass and bluegi II was 95% and 96.8% respectively. Redear exhibited 100% pigment retention for an 11 month period. Mark retention on channel catfish was 100% during a 10 month experiment. Results indicate marks will be retained by certain species for a much longer period, although mark quality will reduce with time.

The growth of fish is an important factor in the useful studies of fish populations. There are several well known methods of comparing growth of fish. Only one will be discussed in this paper. This method uses the formula W; KLn where W is weight in grams, k is a constant, L is length in millimeters, and n is a power, usually near 3. This paper will espouse a variant of the formula, equating W ; KL3. Here, the variable n becomes a constant 3, eliminating the vagaries of n; and the constant k now becomes a variable K changing with length, in order to maintain mathematical validity. K varies with L in this paper although it could be made to vary with Wand to some approximate degree with age. It will be shown that the equation holds regardless of the size of the fish. The advantage of the simplified hyperbolic equation is that it reduces the imput to three variables.

A study was undertaken to determi ne the value of a small otter trawl as a collection tool in 11 reservoirs in Northeast Texas. The collection unit consisted of four sets of 150-foot experimental gill nets, two drags with a 26-foot bag seine and two runs with a la-foot trawl. The seine and trawl collections were made both during the day and at night. Seining accounted for most of the 44 species of fish taken, while trawling produced the greatest number of specimens. Four species were taken only from gill nets, six only by seining and trawling added two exclusive species of fish to the collection list. Trawling has certain limitations and does not replace either gill nets or seines, but serves as a supplement to these two standard methods of collection.

Sodium cyanide has been an effective method for sampling the stream fish populations in Eastern Tennessee. Its portability makes it a practical stream management tool. Cyanide is an excellent cold weather sampling method. Three ounces of cyanide in trout streams and 6 ounces in warmwater streams per cubic foot a second flow will sample 100 yards. In water colder than 55°F mortality of fish is not acute. Rainbow trout and various warmwater fish collected with cyanide and held in aquaria showed no deleterious effects from exposure to the chemical. Reduction in stream invertebrate populations after cyanide application is evident.

The National Survey of Needs for Hatchery Fish was a cooperative effort by the Bureau of Sport Fisheries and Wildlife and the 50 States to obtain information for estimating future nationwide requirements for hatchery fish. During 1966, data were collected on present and future: (1) amount and types of sport fish habitat; (2) amount and types of habitat stocked; (3) numbers and types of fishermen; (4) stocking requirements; and (5) hatchery fish production capabilities. Inland fishing waters amounted to nearly 82 million acres in 1965 and will increase 10 million acres by 2000. Half of the waters are stocked. There were 29 million freshwater fishermen in 1965 and by 2000 there will be almost 64 million. There was a deficit of 287 million hatchery salmon in 1965 and by 1980 the deficit may reach 709 million. Requirements for trout exceeded production in 1965 by 1 million pounds and future deficits are forecast.

Twenty sets of fish collection data were used to compare seven diversity indices. The data sets were chosen to represent the wide variation in habitat, ecologic condition, salinity, as well as other factors, encountered in fishery work. Cross comparisons of several index rankings were made and the dependencies of the various indices discussed. Variation of index score with number of species and with sample size was examined. Results indicate four indices may be applied to fishery work.

Food of striped bass 10 mm. to 110 mm. standard length cultured at the State Fish Hatchery, Durant, Oklahoma was determined during the summer of 1967. Diet of fish in the 10 mm. to 30 mm. class consisted mainly of copepods, supplemented by cladocera and insects. After reaching 30 mm., bass utilized fewer copepods but more cladocera and more insects. Insects and c1adocera then formed the majority of the diet in fish from 60mm. to 100mm. Over two-thirds of the volume of planktonic crustacea eaten were Diaphanosoma sp. Other important crustacea were Diaptomus sp. and Daphnia sp. Fish did not enter the diet until bass reached 69mm. standard length and fish were not important in the diet until bass were over 90mm. No monthly variations in feeding habits were detected. The culicid, Chaoborus sp. was also a significant food item of the smallest length class examined.

Young shrimp have shown rapid growth in brackish-water ponds which had been fertilized, but to which no supplemental feed was added. In 1966, white shrimp (Penaeus setiferus) were stocked at the rate of nine shrimp per square meter of bottom in a pond that had been fertilized with chicken manure. In 1967, brown shrimp (P. a. aztecus) were stocked at a rate of 22 shrimp per square meter of bottom in one pond that was fertilized with rice husks and in another that was not fertilized. In both experiments initial growth was rapid; the shrimp attained bait size (75 to 93 mm total length) in 5 to 7 weeks. This rapid growth was followed by a period of slow growth. In 1967, supplementary feeding produced additional gains after growth had nearly ceased. Survival of the white shrimp was 84 percent, whereas survival of the brown shrimp was 23 percent in the untreated pond and 31 percent in the fertilized pond.

Dylox® was effective against some fish parasites, ineffective against others. Although experimental results were inconsistent, a few workers report success in treating trichodinid protozoans. No success resulted from treating catfish with Ichthyophthirius. Applications of 0.25 ppm (active ingredient! successfully controlled monogenetic trematodes of Gyrodactylus, Dactylogyrus, and Cleidodiscus spp. Parasitic copepods were effectively controlled by weekly applications of 0.25 ppm except during periods of hot weather. Five species of leeches proved susceptible to single applications of 0.5 ppm Dylox. Factors affecting the decomposition of Dylox in ponds are discussed along with their relevance toward the treatment of ponds. limited data concerning residues following various application rates are presented.

This paper reports on pond culture experiments conducted when fingerling blue, Ictalurus furcatus, channel, I. punctatus, and white catfish, I. catus, were stocked in nine brackish water ponds at Rockefeller Wildlife Refuge. All three freshwater species were stocked in ponds with an equal amount of acclimatization to determine survival, growth, food conversion, and to determine if freshwater catfish could be raised in brackish water ponds. In the past, fish culturist felt that catfish could not be grown in coastal ponds with salinities of over 1.5 parts per thousand. In the Rockefeller ponds the salinities ranged from 2.0 to 11.0 ppt. Growth was good among all species. The channel and white grew best, averaging 1.3 and 1.0 pounds apiece. The blues average 0.6 pound. The results of the study proved very promising. Even though survival was low, it is surprising that the mortality was not higher. Predation, mostly by otters, alligators, mink and snakes, was tremendous.

Recent growth of commercial fish farming in the South Central United States has stimulated interest in the habits of fish species adaptable to fish farm environments. In 1964, the food habits of the bigmouth buffalo, Ictiobus cyprine/lus (Valenciennes), were determined in simulated fish farming ponds by comparison of available food and stomach contents. Results indicated competition with channel catfish for food occurred only when supplemental feed is introduced. In this situation channel catfish appear to be more vigorous competitors than buffalo. Stomach contents are compared with volumetric measurements of food organisms available in the ponds.

Catfish production varied 40 per cent among 12 ponds in a uniformity test. Survival, spawning, and trash fish made no significant contribution to this variation. Production was directly related to the amount of certain constituents found in the pond soils, namely, exchangable calcium, electrical conductivity, magnesium content of soil - water (1 :2.5) extracts, and nitrate nitrogen.

The purposes of this study were (1) to determine the feasibility of using isolated columns of water as an efficient way to obtain a natural series of similar bodies of water that are subject to identical climatic and environmental conditions, and (2) to determine the effect of fertilization and the fertilization rate that will give optimum and/or maximum phytoplankton production. Twelve open-ended transparent polyethylene tubes 4' in diameter and 9' in length, were used to isolate vertical "transects" of water in the study pond. Measurements of oxygen, pH, water temperature, and turbidity were made to determine any physical or chemical changes which may have been attributable to the tubes. The affect of fertilization was studied by applying three rates of single analysis of commercial fertilizer to the test tubes. The three experimental rates chosen were equivalent to 50, 100, and 150 pounds of 20-20-5 analysis fertilizer per surface acre of water.

Five types of fish population sampling gear were intensively fished in a 263 acre Oklahoma reservoir. The relative species compositions are compared, both between and within sampling methods and with bag seine samples taken at draining. A method using accumulative percentages for determining the length of time necessary to sample a population with specific gear to estimate species composition is described. Bated and unbaited nets had similar catch rates and species composition. Bluegill were more vulnerable to seine hauling during daylight hours than seine hauling at night. Gill nets failed to produce sufficient numbers of fish for statistical analysis, but larger mesh sizes captured flathead catfish and freshwater drum missed by most of the other types of gear. Small mesh gill nets revealed essentially the same species composition as rotenone and shocker samples. Trap nets caught white crappie in greater proportion than their numbers in the population.

Wisconsin-type trap nets were investigated to determine methods necessary to adapt this gear to TVA reservoirs, to establish the best operational procedure, and to determine the potential of this gear in an expanded commercial fishery. The study was conducted primarily in Wheeler Reservoir, Alabama. Three trap nets, modified in amount of flooring, mesh size, and floatation, were fished in combination with three lengths of lead. The lead of intermediate length was constructed of a smaller mesh size (4- instead of 5-inchl than the shorter and longer leads. Modifications which resulted in larger commercial catches were a floor constructed in both cribs and the heart, a smaller mesh size in the heart (4- instead of 5·inch), and a 400-foot lead of 4-inch mesh. The smaller mesh in the heart resulted in a larger catch of industrial size freshwater drum, while the smaller mesh in the lead resulted in a larger catch of gizzard and threadfin shad.

One by two-inch mesh wire fish traps were fished for 5,135 trap days in Old Hickory Reservoir between August 1, 1963 and June 30, 1964. Of the 2,661 fish caught, 83.2 percent were commercial fish, 16.2 percent were sport fish and 0.6 percent "other" species. Carp (Cyprinus carpio) constituted 61.6 percent of the catch. Crappie (Pomoxis sp.) made up 12.0 percent of the total catch. Deep baited sets had the highest catch rate (1.17 commercial fish per trap day) and also the highest percentage of commercial fish in the catch (98.7 percent). Unbaited traps had the lowest catch rate (0.06 commercial fish per trap day regardless of depth), with 56.5 percent and 76.9 percent of the catch consisting of sport fish in deep and shallow sets, respectively. The average size of the fish caught was small. It was concluded that wire traps could be legalized in Old Hickory Reservoir for local residents to catch fish for home consumption without adversely affecting sport fish populations.

Oklahoma commercial fishermen on Lakes Texoma, Grand, Eufaula, and Gibson were studied from July 1967 to June 1968. In each quarter samples of fish were weighed prior to cleaning, by a commercial fisherman, and immediately afterwards. Linear and curvilinear regressions are fitted to these data. Between lake and between season comparisons are made. Information is presented for smallmouth buffalo, bigmouth buffalo, flathead catfish, carp, drum, river carpsucker, and paddle fish.

The life histories of smallmouth buffalo (lctiobus bubalus) and freshwater drum (Aplodinotus grunniensl were studied during 1966-1968 in conjunction with the evaluations of commercial fishery gear on Wheeler Reservoir. In this reservoir, smallmouth buffalo grows as fast as or faster than it does in other reservoirs. They are 5 to 6 years old and 17 to 19 inches long before they are abundant in the commercial catch. Drum growth is slower in Wheeler than in other waters; they are not important commercially until they are 7 to 8 years old and 16 to 19 inches long. Asiatic clams, 1 to 2 mm in diameter, and copepods were the dominant food items for all sizes of buffalo. Drum less than 10 inches fed primarily on diptera larvae; those over 10 inches fed primarily on Asiatic clams greater than 10 mm in diameter and gizzard shad. Peak spawning periods in 1967 were mid-April for smallmouth buffalo and late-May for drum. REproduction potential of both species is high.