Journal of the Southeastern Association of Fish and Wildlife Agencies

A modified gill net known as a hobbled gill net was utilized in a commercial fishery in 3,300-acre Lake Carl Blackwell in Central Oklahoma from September, 1957 through December, 1958. A total of 3,200 fish weighing 20,252 pounds was taken in 1,085 net days, a net day being 300 feet of net fished 24 hours. Non-game fishes represented 97 percent by weight of the total catch. Hobbled gill nets proved particularly effective in taking flathead catfish, which comprised 63.4 percent by weight of the total catch. The average catch of flathead catfish increased from 4.9 to 13.0 and 14.6 pounds per net day for 3.0-, 3.5- and 4.0-inch bar mesh nets respectively. In general, the catch of all other species decreased as the mesh size increased from 3 to 4 inches. Hobbled gill nets may be an efficient modification over standard commercial gill nets and a more selective gear for large flathead catfish than other entanglement gears.

The results of applying ground limestone (CaCO2) and quicklime (CaO) to hatchery ponds used for the culture of bluegills (Lepomis macrochirus, Raf.) are described. Effects appeared to be beneficial in the sample of ponds treated. Quicklime was difficult to apply because of caustic effects to skin of personnel handling it. Laboratory experiments indicated that hydrated lime (Ca[OH].) could be used to produce a pH as alkaline as that obtained from quicklime provided that an equivalent amount of calcium was used in the hydrated form.

The results of two years experimental weed control in Georgia Farm Ponds using silvex,2 propylene glycol butyl ether ester, dalapon, sodium salt of 2,2dichloropropionic acid; 2, 4-D granules of iso-octyl ester of 2,4-dichlorophenoxy acetic acid. Residual control and overall effectiveness is evaluated over a twoyear period on acquatic weeds in approximately 100 ponds. Preliminary screening of Inverton, an invert emulsion of 2, 4, 5-trichlorophenoxy acetic acid; Carlon, a solution of dalapon and silvex; and simazine, 2-chloro-4, 6 bis( ethylamino) -S-trizaine are presented. Different concentrations were used and observations made during 1958 and 1959. Results are presented for different herbicides and evaluation made for their effectiveness on specific aquatic weeds. Silvex appears to have the widest range of control for underwater and emergent aquatic weeds. Preliminary results indicate this chemical is as effective as sodium arsenite in many situations.

Laboratory tests were conducted in aquaria to determine the effectiveness of Sulfoxide as a synergist to rotenone for use as a fish poison. In order to compare the synergized product with standard formulations, Pro-Noxfish (2.5 percent rotenone, 2.5 percent Sulfoxide,S percent other cube extractives, and an emulsifier) was compared to Noxfish (5.0 percent rotenone, 10 percent other cube extractives, and an emulsifier), and to powdered cube (7.3 percent rotenone). The relative toxicities of the three formulations were found to vary with water temperature, species of fish, and size of fish tested. Eight species were tested at approximately 70° F. for 72 hours. The concentrations, expressed in p.p.m.

Following the recommendations of a three-year comparative fishery study of Lakes Ouachita, Hamilton and Catherine near Hot Springs, Arkansas, a rough fish removal project was carried out on 3,OOO-acre Lake Catherine, October 25, 1958. The chemical (Pro-Noxfish) was applied at varying concentrations over approximately three-fourths of the drawn-down area of the lake. The water level was manipulated so that the treated water infiltrated the untreated portions. As a result, a selective shad and drum kill was obtained over the entire area of the lake. Bank counts failed to give an acceptable quantitative estimate of numbers and weights of fish killed. A more satisfactory estimate was obtained by the use of data obtained from previous rotenone population samples. As part of the management plan, the lake will be restocked with large numbers of yearling and fingerling game fishes. Evaluation of the management work will be carried out by continuing Dingell-Johnson Project F-5-R.

The reservoir has a surface acreage of 160,500 and contains two rather dissimilar lakes, Lake Moultrie and Lake Marion. Channel catfish (Ictalurus punctatus) are virtually unknown in Lake Marion, exist in relatively small numbers in Lake Moultrie, and are abundant in the tailrace sanctuary. White catfish (Ictalurus cattts) are present in large numbers in both lakes and the tailrace sanctuary. The channel catfish of Lake Moultrie and the tailrace sanctuary grow larger and faster, live longer and are in better condition than any channel catfish described in the literature. They, also, differ slightly in morphology.

Beginning with a stocking of 600 four- to six-inch rainbow trout in 1948 in the Norfork Dam tailwater located in North Central Arkansas, a fishery soon developed which was entirely new to the area. With the completion of Bull Shoals Dam in 1952, investigations began which soon showed that the native fishery was destroyed for many miles below the high dams. A trout stocking program carried on in conjunction with an investigational project produced such excellent trout fishing that the area became nationally famous within a few years, and a modern trout hatchery was constructed just below Norfork Dam by the U. S. Fish and Wildlife Service for the purpose of producing trout for stocking the White River and its tributaries. By 1957 trout were being stocked in 91 miles of tailwater streams which supported 47,792 man days of fishing, generating $684,732.00 worth of business to the fishing service operators alone.

The fall-winter foods of otters living along the coast are largely fishprincipally carp, catfish, suckers, and sunfish. The otters' diet at other seasons of the year is largely comprised of fish, blue crab, and crayfish. Other foods, all taken in small quantities, are shrimp, clam, water beetles, decapod, muskrat, rails, and waterfowl. An examination of 53 female otters from northeastern counties over a 12winter period (1947-48-1958-59) showed that breeding starts during January and continues into February and possibly into March. Of eight gravid otters in a study sample of 53, five contained three embryos, two contained two, and one contained four embryos. This is an average of 2.88 embryos per female. Sex data obtained on 273 otters showed 149 (55%) males and 124 (45%) females. This is 120 males for every 100 females. Weights were obtained on a total of 238 otters.

Length and weight data were gathered during a short time-period on several species of fish from a large lake and a connecting marsh canal. The marsh had recently gone dry, forcing the fish to crowd into the canal. Analysis of covariance was used to compare the length-weight relationship of largemouth black bass (Micropterus salmoides) , redear sunfish (Lepomis microlophus) and bluegill (Lepomis macrochirus) from both habitat types. The bass from the canal were found to be significantly heavier for their length than those from the lake. Various possible explanations for this phenomenon are discussed. The author's conclusion is that the most logical explanation for the phenomenon is increased feeding by the bass under these crowded conditions. No detectable difference was found in the length-weight relationship of redear sunfish and bluegill from the two habitats. No chain pickerel (Esox niger) were captured in the lake but several hundred were taken in the canal.

Laboratory experiments were conducted to determine the toxicity of Noxfish (an emulsifiable formulation containing 5 percent rotenone) and Pro-Noxfish (an emulsifiable formulation containing 2.5 percent rotenone plus 2.5 percent Sulfoxide as a synergist) to eggs of common carp (CyprinMs carpio) and fathead minnows (Pimephales promelas). Spawning devices were added to brood ponds and examined daily to obtain eggs of known age for testing. The 325 carp eggs were 24 to 48 hours old when treated. Ninety percent of the carp eggs in control containers hatched. The LD.o's obtained for carp eggs at approximately 75° F. were: Noxfish, 0.091 p.p.m., Pro-Noxfish, 0.178 p.p.m. Fathead minnow eggs less than 31 hours old or 101 to 120 hours old were equally susceptible to the poisons. Ninety percent of the fathead minnow eggs in control containers hatched. The LD50's obtained for fathead minnow eggs at 70° to 76° F. were: Noxfish, 0.142 p.p.m.; Pro-Noxfish, 0.233 p.p.m.

The channel catfish (Ictalurus punctatus) has proved to be a very promising sport fish in ponds. Fingerlings stocked in February 1958 in a 12.4-acre pond at the rate of 2,000 per acre in combination with fathead minnows and largemouth bass, and given supplemental feeding daily except Sunday, averaged 0.7 pounds by September. During the following periods, September 24 to December 8, and March 14 to October 6, fishermen caught per acre 1,292.5 pounds of channel catfish, 36.9 pounds of largemouth bass, and 27.0 pounds of miscellaneous sunfish. The number of fishing trips per acre averaged 579 with a catch of 2.3 pounds per trip. Fishermen harvested 62 percent of the catfish stocked. The pond was drained November 17, 1959 and 180 channel catfish weighing 391.2 pounds, 51 largemouth bass weighing 34.5 pounds, 907 fatheads weighing 2.4 pounds, and 80.2 pounds of “wild” fish were recovered per acre.