Journal of the Southeastern Association of Fish and Wildlife Agencies

Wild-trapped sandhill cranes (Grus canadensis pratensis) captured and moved to habitat occupied by cranes 152 miles away did not return "home" and were seen near the release site up to 20 months later. The frequency that the translocated birds were seen near the release site indicated that dispersal had been minimal and that restocking in suitable habitat might be done with relatively few wild-trapped cranes. Dispersal behavior is an Important factor m restockmg success with wildtrapped animals and determines the minimum number of individual animals required. To measure dispersal behavior in sandhill cranes in anticipation of future restocking efforts, we trapped and moved cranes from high population areas to other occupied crane habitat. We thank M. J. Fogarty and D. W. Peterson for help in capturing some of the cranes.

Bobwhite nesting success data was collected during a five year (1967-71) study on an area with a high population density (2 + quail/acre) and a three year (1969-71) study on an area with an "average" density (4 acres/ quail). Despite the differences in population density and the intensity of habitat management, the season nesting success on both areas averaged approximately the same, 17.5 percent on the high density area (based on 1,412 nests studied) and 20.8 percent on the "average" density area (based on 313 nests studied.

Farm ponds and community lakes continue to attract a large number of fishermen. The manageability of these waters for increased fish production offers opportunities for substantial gains in terms of benefits to fishermen from management input costs. Intensive culture of channel catfish, tilapia and mirror carp can provide sport fishing opportunities, especially where fishing pressure is intense. Almost a ton of channel catfish per acre has been harvested by sport fishermen from intensively managed ponds. Problems associated with intensive culture are nutrition, disease, and the diminished aesthetics of fishing an intensively managed pond. Present management practices for bass-bluegill ponds are adequate, but intense study of optimum rates of exploitation and fertilization should provide for more efficient techniques. Strategy and tactics for the future should consider energy flow patterns in fish communities.

Despite continued deterioration and outright destruction of many streams Missourians still have a notable and diverse stream resource. Nearly 9,900 miles of permanent streams and 8,200 miles of intermittent streams with permanent pools remain. Positive stream management practices and activities in Missouri include water quality surveillance and control, access site acquisistion and development, stocking for put-and-take trout fishing, National Scenic Riverways designation, commercial fishing on some larger rivers, and continuing research projects. Three examples of application of research to stream resource problems are discussed. The first is an evaluation of gigging for rough fishes. On Big Piney River, it was shown that giggers had catch rates up to 22 times higher than hook and- line anglers. The harvest by gig, expressed as pounds per acre, nearly equaled the average annual harvest by anglers.

There are about 500 reservoirs (larger than 500 acres), totaling 4.3 million acres, in the 14 States of the Southern Division. Angling demand is predicted to double on Southern waters by the year 2000, and most of the increase is expected to be satisfied by man-made lakes. Southern reservoirs are typically below average in basic fertility, but long growing seasons foster high annual production rates, resulting in above average sport fish yield potentials. The steady accumulation of reservoir environmental and biological data during the past quarter century has greatly increased our ability to predict standing crops and angler harvests and to devise management practices based on production potentials. Production is primarily controlled by available nutrients, basin morphometry, water exchange rate, climatic cycles, eutrophication rate, and species composition.

This summary and discussion covers four papers on current fishery management problems and programs in small ponds and community lakes, reservoirs, streams, and coastal and estuarine environments. Problems are classified in four major categories: economic, political, social, and biological. Biological problems are subdivided as either environmental (physical-chemical) or biotic. In discussing the goals and objectives of fishery management, a distinction is made between the terms harvest, catch and yield, and the goals of maximum sustained harvest and optimum sustained yield. Discussion of management of largemouth bass populations in reservoirs develops the hypothesis that bass biomass may amount to only one half to one sixth of the potential sustained carrying capacity in some waters. Calculations are made to project changes in biomass, production, catch and harvest that may result from the application of various protected-length regulations.

Claytor Lake, Virginia, an 1820 ha main stem hydroelectric reservoir, was studied for one year to determine the effect of water discharge on reservoir phytoplankton. Number/liter, areal units/liter, average cell size, and chlorophyll a content were used as measures of photoplankton abundance. Rate of water discharge had an adverse effect on reservoir phytoplankton during spring and summer. Although increased rate of water discharge caused increased phytoplankton loss, the adverse effect of rate of water discharge on reservoir phytoplankton populations was probably at least partially due to additional discharge of nutrients. The inverse relationship between rate of water discharge and reservoir phytoplankton populations decreased in the uplake direction.

An investigation of the effects of increased sodium chloride concentrations on striped bass fry survival was conducted at the Auburn University Fisheries Research Unit from April 8 to July 7, 1972. The mean survival of fry in ponds with increased sodium chloride concentrations was 7.65% as opposed to 1.70% in six control ponds. The survival in all ponds was highly variable, ranging from 0.33 to 39.50% in increased sodium chloride ponds and from 0.00 to 9.58% in control ponds.

The effect of the polychlorinated biphenyl (PCB), Aroclor 1254, in eggs of the sheepshead minnow, Cyprinodon variegatus, on fertilization success and survival of embryos and fry was investigated. Adult fish were exposed for four weeks to 0.1,0.32, 1.0,3.2 or 10.0 ug/l of PCB, then injected twice with 50 lU of human chorionic gonadotrophin to stimulate egg production. The eggs were fertilized, placed in PCB-free flowing seawater and observed for mortality. Fertilization success was unimpaired by concentrations in eggs as high as 201 ug/g but survival of embryos and fry was reduced. Usually, fry from eggs containing 7.0 ug/g or more began dying 24-48 hours after hatching. If this PCB affects other species similarly, then populations of fish that presently have comparable concentrations in their eggs may be endangered.

Tests were conducted to determine (1) the acute toxicity of dieldrin in flowing sea water to American oysters (Crassostrea virginica), pink shrimp (Penaeus duorarum), grass shrimp (Palaemonetes pugio) and sheepshead minnows (Cyprinodon variegatus) and (2) the rate of dieldrin uptake and depuration by spot (Leiostomus xanthurus). Acute (96-hour) EC50's were: oysters, 12.5 ug/1; pink shrimp, 0.9 ug/l; grass shrimp, 11.4 ug/1; and sheepshead minnows 23.6 ug/I. Spot exposed to 0.0135,0.075,0.135,0.75 or 1.35 ug/l for 35 days accumulated the chemical with maximum concentrations attained in II to 18 days. Maximum whole-body residue (wet-weight) was 6,000X the concentration in test water. Spot contained no detectable dieldrin residues at the end of a 13-day depuration period in dieldrin-free water. Tissue alterations, such as subepithelial edema in gill lamellae and severe lysis and sloughing of the small intestine epithelium, occurred in spot exposed to 1.35 ug/1 for four days.

The White Amur, Ctenopharyngodon idella, was found to be able to withstand recommended pond treatment concentrations of potassium permanganate, formalin, copper sulfate, and malachite green. In all instances, 100% of the test fish survived a 96 hour tolerance period at concentrations above the dosages recommended and used by the Arkansas Game and Fish Commission for disease and vegetation control in earthen ponds. Both rotenone and antimycin were bio-assayed for possible use as a toxicant selective toward the White Amur. Both show promise as 100% mortality was recorded for test fish at extremely low concentrations in aquariums.

A comparison of tolerance of fingerling black crappie, white crappie and largemouth bass to Fintrol-5 was conducted in aquaria. White crappie were found to be more susceptible to Fintrol-5 than were black crappie and largemouth bass. Largemouth bass and black crappie showed similar tolerance to the toxicant. The mortality of largemouth bass and black crappie was significantly reduced at a pH of 8.0-8.5. All three species suffered significant mortalities beginning with .04 ppm Fintrol-5 at a pH of 7.0. One ppm KMn04 significantly reduced mortality by detoxifying Fintrol-5.

Six experimental catfish feeds, containing 29, 36, and 42% crude protein at metabolizable energy (ME) levels of 1000 and 1300 kcal per Ib, were fed to fingerling channel catfish in 24, 1/ I0-acre earthen ponds for 165 days. Each dietary treatment was randomly assigned to four ponds which were stocked at a rate of 4,000 fish per acre. Feed allowance was increased biweekly on the basis of fish weight gain until a maximum daily allowance of 40 Ib per acre was reached. The higher energy plane resulted in greater weight gains, more fish protein produced per acre, and slightly fatter fish, at each dietary protein level. At the lower ME level the difference in growth among fish fed the 29, 36, and 42% protein diets was not significant (PV.05). At the higher ME level the fish showed increased gains with each increase in diet protein percentage.

Two experimental fish diets, one consisting of50% roasted soybeans and 50% fresh fish, and another consisting of 30% soybeans, 20% corn meal, and 50% fresh fish, both with vitamin and mineral supplements, were compared to Oregon pellets in a 6 week feeding trial using yearling channel catfish (lctalurus punctatus). The experimental diets were ground, blended and pelletized by passing the ingredients through a food chopper four times. Both mixtures proved highly attractive to the fish. Fish fed either experimental diet grew as well as fish fed the Orgon pellets. The experimental diets are suggested for use in parts of the world where commercially prepared fish feeds are not available. The diets also present the possibility of using non-commercial fishes as feed for more valuable fishes. It was observed that the fish exhibited fighting when the vitamin mix was omitted. A variety of pelleted feeds for fish are now available in the United States.

Investigations have shown that small (less than 10 cm) channel catfish fingerlings, Ictulurus punctatus Rafinesque, gained as much weight in a 10 week period on a diet of 25%-75% oxidation pond algae-commercial feed as did control animals fed 100% commercial feed. Larger fish (20-25 cm) fed the algal-supplemented diet did not gain as much weight in 10 weeks as did control fish on 100% commercial feed. Whole body protein and fat levels did not differ significantly between control and experimental fish.

Chinese waterchestnut was grown in rafts floating on catfish pools to determine effects on production of channel catfish fed daily. This plant may remove nutrients from the water and increase catfish production by improving water quality and, also, produce a second crop, the edible corm ofthe plant. Catfish were stocked in March, Chinese waterchestnuts were planted in April, and both were harvested in October. Survival and production of fish were 56% and 1230 kg/ha, 86% and 1871 kg/ha, and 87% and 1952 kg/ha in pools with fish only, fish and raft, and fish and raft with waterchestnut, respectively.

Channel catfish can be cultured at high densities in carefully managed recirculating raceway systems. Various flow rates, exchange rates, and tank to filter ratios were investigated in ten recirculating systems employing biological filters, settling chambers and foam strippers. Limestone, shells, styrofoam and teflon rings served as effective filter media, but coal slag restricted water flow and was not satisfactory. An equation was developed to evaluate the effects of system design on water quality. Water quality varies directly with fresh water exchange, flow rate per tank, and the filter size. Production was greater in systems with small tanks and large filters (5 Ib/ft3) than in systems with large tanks and small filters (1 lb/ft3). Densities in excess of 7lb/ft3 per tank have been obtained, indicating recirculating systems may become an increasingly important method of fish culture.

Techniques were investigated for growing channel catfish, lctalurus punctatus (Rafinesque), from fingerlings to harvestable size fish during the summer months in a recirculation, flowing water fish culture system in South Georgia. When stocked at a density of 2,000 fingerlings per 100 ft raceway unit, mean production was more than 2,400 Ib per unit with a feed conversion ratio of 1.28 to 1. Survival of the fish was 98.1 %. Successful culture of 2,400 fish in one unit indicated that the carrying capacity of the raceways used in this study was greater than 2,000 fish. There was a gradual deterioration of water quality as it flowed through the raceways but, none of the water quality parameters measured were considered detrimental to the fish. Infestations of Cleidodiscus. Scyphidia and Trichodina were controlled by adding formalin to the water in the raceways at the rate of 30 ppm with the water flow stopped for 1 hr.

A comparison was made with a floating and sinking ration of similar analysis produced by the same manufacturer. This study demonstrated an increase in catfish production when using the sinking ration. Moreover, the sinking feed produced fish of a larger average size, a better food conversion, and a smaller Ktl factor. Use of sinking feed represented a savings of approximately $54 to $72 per acre on the feed bill. Data were compared for the influence of fingerlings size at stocking (4.5, 6.5 and 8 inch) upon catfish production. The larger fingerlings experienced larger S-factors; however, the high percent of harvestable size justified using this size fish for one year's production.

The survival of bass (Micropterus spp.) caught and released during the Rebel Invitational B.A.S.S. Tournament on Ross R. Barnett Reservoir, Mississippi, April 4-6, 1973 was studied. Two different techniques for handling the bass prior to release were evaluated. A total of 1,863 bass were caught by 159 fishermen during the tournament. Of these, 197 (10.57%) were judged to be dead at the weigh-in. The remaining 1,666 bass were randomly divided into two groups for treatment or non-treatment. A total of 830 bass were injected IP with oxytetracycline and marked prior to release into a 0.8 hectare blocked-off area. The 836 non-treated bass were handled in the same manner except they were not injected or marked prior to release into the study area. A significantly higher number of treated bass (96.99%) survived the 19 day study period than did the non-treated bass (91.63%).

Homing behavior of flathead catfish in an Oklahoma reservoir was observed by tracking fish bearing a 74 kHz transmitter which had been implanted in the peritoneal cavity. Homing is described from 1,190 fixes (site locations) obtained on 22 flathead catfish. The average tracking interval was 18.7 days. Homing occurred in 8 of 12 (67%) fish displaced a distance of 1.3-2.7 km from the site of capture. Average accuracy of homing fish was within 182m of the original site of capture. One transmitter tagged fish, displaced 1.82 km, returned to the site of capture within 1.7 days. All 12 displaced fish, regardless of whether or not they homed, moved away from their release site before establishing a home range. Most (70%) of the 10 non-displaced fish remained in a well-defined area near the site of release (i.e., the original site of capture) which also provided evidence that the fish recognized a home area.