Journal of the Southeastern Association of Fish and Wildlife Agencies

The technique of operation of the haul seine as traditionally used in the large fresh water bodies of Florida is discussed. Limiting factors inherent in the sampling device are enumerated and illustrated by seine catches from several lakes. Rotenone studies from some of these lakes are contrasted with the seine catches. The results of creel census studies in lakes extensively fished by sportsmen, by reflecting proportionate quantities of game fishes similar to quantities taken in the haul seine, are quoted as further validation for its use in qualitative population. sampling. Difficulties in quantitative sampling by this method are discussed. It is shown to be of questionable value when employed for approaching absolute terms such as productivity in pounds per acre except in certain special cases. The value of the haul seine for purely relative comparisons is emphasized.

To facilitate the evaluation and use of population studies, reports should include: 1. A description of the area sampled, including the chemical classification and physical type of water, the type of bottom, depth of water, speed of movement and other information necessary to describe the environment from which the population came. 2. A description of the method of sampling employed in sufficient detail to enable the results to be evaluated and compared with results of other surveys. 3. Methods of measuring the results should be stated. The report should state if an attempt was made to recover fishes of all sizes, and if all fish were weighed or partly weighed and partly estimated. Such information is necessary for evaluation of the reliability of the results. 4. The population composition should be listed by species, with the numbers and weights of fish in each inch-group.

A simple method for the comparative testing of herbicides for emergent weeds was developed and used over a three-year period to compare the effect of recently introduced herbicides with that obtained from the use of a 2,4-D ester in a fuel oil carrier. The herbicides tested included amitrol (3-amino-l, 2, 4-triazol), dalapon (sodium salt of 2, 2 dichloropropionic acid), erbon (2- (2, 4, 5 tricholorophenoxy) ethyl 2,2 dichloropropionate), Kuron (propylene glycol butyl ether ester of 2-(2,4,5 trichlorophenoxy) propionic acid), Kuramine (amine formulation of 2-(2,4,5 trichlorophenoxy) propionic acid), CMU (3-(p-chlorophenyl) -1, 1-dimethylurea) and the propylene glycol butyl ether ester of 2,4-D. These compounds were tested singly and in various combinations of two herbicides. TCA (sodium salt of trichloroacetate) was combined with several of the forms also.

From November, 1955, through May, 1956, trammel and riprap nets of 3-, 3.5- and 4-inch bar mesh and gill nets of 3- and 4-inch bar mesh were fished by resident commercial fishermen under the supervision of State Fisheries Biologists, in T. V. A. lakes of Alabama. A total of 10,425 fish which weighed 42,689 pounds was caught, of which 95.4 percent was rough fish. All of the nets were selective in taking rough fish. Whip set trammel nets were the most effective type of net fished, followed by fixed trammel, riprap anc~ gill nets. In general, as the mesh size increased from 3 to 4 inches, the effectiveness of all nets decreased.

Ponds stocked April 30 with 80 Tilapia mossambica per acre and drained October 16 produced in the 170-day experiment 1,480.9 pounds tilapia per acre in a fertilized pond and 3,224 pounds per acre where feeding was added. Tilapia (1- to 2-inch) stocked into ponds June 13 reached 5 to 8 inches in size in 126 days. A 2.6-acre pond was stocked April 18-20 with 80 brood tilapia per acre. The pond was fertilized and the fish fed. Tilapia hatching in this pond grew large enough to provide fishing by August 1. In the first 2-week period of fishing, the catch per acre was 1,222 fish weighing 226 pounds. These fish feed upon plankton and filamentous algae and may be of value in ponds for the control of the latter.

Perhaps the most universal problem in many of Kentucky's streams, from the angler's viewpoint, is that of excessive numbers of rough fish in proportion to the numbers of game fish. This paper presents the findings of a Dingell-Johnson project that has been concerned since 1952 with the manipulation of populations in 3 streams typical of types found in the state. The upper 46 miles of North Fork River in Mason County and 12 miles of Whippoorwill Creek in Logan County were treated with 5-percent powdered rotenone in 1952 to eradicate their entire fish populations. Both streams were immediately restocked with game and panfish species. Annual sampling of the population of both streams revealed a gradual reversion to the original population composition in each stream.

The continued spawning success of striped bass, Roccus saxatilis, within the reservoir during the past three years, in spite of greatly reduced lock operations, is evidence which heavily supports the resident hypothesis. Striped bass feed heavily upon mayfly nymphs during the spring months, but take clupeoid fish almost entirely for the remainder of the year. The results of a three-year creel census ending August 31, 1957, shows that the number of striped bass caught and the percent of the total catch which striped bass represents has approximately doubled for the past two years. The average catch per trip has increased from 1.7 fish to 3.0 fish since 1955. Other data demonstrate a decided change in preference to striped bass fishing from other species by fishermen. An intensive gill net effort between June 5, 1956 and August 6, 1957 took 5,730.4 pounds of fish. Of this total, 60.1 percent was striped bass.

A method is described for sexing striped bass through use of serrated jaw ear forceps. The instrument is used to extract gonads from dead fish in samples of commercial catches, without incurring damage to the fish which affects the market quality. The gonads are examined later in the laboratory and are identified as male or female. The technique has proven satisfactory in large scale sampling of commercial catches. This method also holds promise for use on other species of fish in which sex ratio studies are important.

Seven charges of Nitromon Primer S were exploded at six stations on the Aucilla River. Results of three explosions, each consisting of ten pounds of explosive, at Station No. 1 killed at least 842 shortnose gar, 300 longnose gar and three channel catfish. The successive treatments at this station indicated a reduction of longnose gar in the area. More shortnose gar were destroyed in the third explosion than in the first and second. Variation occurred in the results at other stations. It was noted gar concentrations could be detected by their surfacing activity. At all stations where this activity was noted, large numbers of gar were killed without destroying many fish of other species. At stations where this activity was not noted, frequently, numerous fish of other species were destroyed.

An investigation of the stomach contents of bluegill, black crappie, and redear sunfish was made from specimens collected during several months of 1948, 1949, and 1950, in Lake George, Florida. Major items found in stomachs of 432 large bluegills were: aquatic vegetation, crustacea, insecta, and fish eggs. Fifty-five stomachs from small bluegills contained, principally, Cladocera and Diptera larvae. Dorosoma petenensis vanhyningi (Weed) was the major food organism found in 145 black crappie. An analysis of 69 redear sunfish stomachs showed snails (Amnicola sp.) were the dominant food of this species.

A study of the life history of the black crappie Pomoxis nigromaculatus (LeSueur), from Lakes Eustis and Harris, Florida, was made in 1952 and 1953. A comparison of the age composition of the individual and combined samples of 318 Lake Eustis and 403 Lake Harris black crappie showed a similarity existed between the two populations. The scale reading indicated few crappie reached ttte VIII group or older in Lake Eustis and few reached the VII group or older in Harris. Males and females showed only minor differences in growth. Calculations of growth from scale measurements yielded the following estimates of length at the end of the first eight years of life in Lake Eustis: first-2.0 inches; second-4A inches; third-6.8 inches; fourth-8.3 inches; fifth-9A inches; sixth-10.4 inches; seventh-l1.2 inches; and eighth-l1.7 inches.

Results of four experiments on 5.5-acre Deer Island Lake demonstrated that selective poisoning was a practical method for reducing the gizzard shad population. Past haul seine efforts had effected only a temporary reduction in this lake. A concentration of 0.04 p.p.m. of 5 percent emulsified rotenone killed very few gizzard shad. A 0.1 p.p.m. concentration resulted in a conservatively calculated kill of 4,651 pounds or 846 pounds per surface acre. An application of 0.15 p.p.m. concentration killed larger shad as well as a few bass. A subsequent application of 0.1 p.p.m. concentration produced a large unexplained kill of bass.

Copies of the specialized paper and information available from Information and Education Division, Florida Game and Fresh Water Fish Commission, Tallahassee, Florida upon request.