Journal of the Southeastern Association of Fish and Wildlife Agencies

The history of the "nursery' area concept in fisheries management dates back several years and includes varying techniques including fencing of a shallow bay of a reservoir to protect fish on their spawning grounds, utilizing sloughs adjacent to reservoirs for spawning grounds and making use of sloughs, old river lakes and small ponds as nursery areas for young fishes which during high water migrate into the river. One of the most recent modifications which has been put into effect on five of the major reservoirs in Arkansas includes a separate structure nursery pond which is built adjacent to the receiving reservoir and connected only by a manually operated gate and drainage canal system. This type nursery pond has a sizeable watershed to permit annual refilling but one that is not too extensive to cause frequent flushing of fertility from the pond.

This study completes a segment of a project to evaluate the use of anhydrous ammonia as a fisheries management technique in small impoundments. Objectives were to determine the feasibility of using anhydrous ammonia for fish eradication, for pond fertilization, and for vegetation control. Treatments in 15 pounds in Central Texas indicate that anhydrous ammonia fulfills these objectives. Anhydrous ammonia was selected because of known toxicity to fishes and because ammonia is a naturally occurring compound. Thus, the use of anhydrous ammonia as a total or selective population control agent will not leave a persistent nondegradable residue in a pond. Treatment rates varied from 13 to 40 ppm of anhydrous ammonia. Higher treatment rates caused total kills while lower treatment rates appeared selective for certain species. Phytoplankton and zooplankton populations were decimated and recovered slowly.

The commercial fishery on four Oklahoma lakes (Eufaula, Gibson, Grand and Texoma) from which approximately 85 percent of the total state commercial harvest is landed was studied from July 1967 through June 1968. Thirty to forty-eight fishermen fished gill and trammel nets throughout the study period. Legal restrictions limited gear to 3 inch and larger bar mesh. The amount of fishing effort expended by mesh size and lakes was studied. Approximately 70 percent of the total effort was fished with 3 and 3% inch bar-mesh nets. On the lakes studied, approximately 50 percent of the effort was fished on Lake Texoma. Monthly and yearly percent catch composition was determined and the average lengths, weights and condition factors for the fish harvested were computed. The catch was primarily composed of buffalo, flathead catfish, and carp with average weights of individual fish landed being 5.3, 5.0, and 7.5 pounds, respectively.

Bluegill and redbreast populations were sampled by electric shocking techniques from two normal areas and an area affected by the heated discharge of a power generation plant at Lake Sinclair, Georgia. Growth of the fish was derived by the Lea method from measurements of the distance between the last formed annulus to the edge of the scale. By comparison of the study areas, temperature was found not to be the controlling factor of bluegill and redbreast growth in the discharge area.

Each spring and early summer the Corps of Engineers and the associated conservation agencies of the various states work together to program and operate the Corps' reservoir levels so that a minimal alteration of environment will occur during the spawning period of game fish in these reservoirs. The demands of flood control, navigation, hydro-electric power and fisheries resources must be coordinated to produce a condition in which these varied interests are working together to produce the required results to the benefit of all. Communications between all involved agencies during the time of gamefish spawning, and notification of operational procedures is the major contributor to failure or success at this time. Public awareness of the problems involved as well as the action being taken by all agencies decreases the usual rash of complaints against both the conservation agencies and the Corps of Engineers.

A total of 8525 striped bass, Morone saxatilis (Walbaum), were tagged and released in Virginia during 1968 and 1969. Releases were grouped in three periods: (1) 3195 in winter 1968, (2) 2439 during summer-fall 1968; and (3) 2891 in winter 1969. Streamer disc tags, employed in winter 1968, were subsequently replaced by internal anchor tags (Floy Tag No. FD-67). This substitution shortened application time and eliminated a source of bias intrOduced by the entanglement of disc tags in gill nets. Releases were made in the James, York, and Rappahannock rivers in all three periods. Rewards of one dollar have been paid for return of tags. Percentages of returns within tagged year-classes increased with age, indicating change in fishing mortality rates of striped bass during their initial 3 to 4-year residence in the lower Chesapeake Bay system. The older the pre-migrating tagged fish, the more likely its recapture.

Experimental culture of striped bass in Oklahoma State Fish Hatcheries was initiated in 1965. This work has resulted in several procedural guidelines which will enable the successful production of striped bass. The application of these guidelines to production on Oklahoma's antiquated State Fish Hatchery System is discussed. Factors which have influenced the application of desired methods on three State fish hatcheries are: Availability of sufficient water; fertility of ponds; aquatic vegetation; availability of equipment and supplies; quality of hatchery personnel; climate; amount and suitability of harvest equipment. These factors are discussed in relation to the 1969 rearing season.

Hidden Valley Lake is an acid water, shallow trout impoundment located in southwest Virginia at an elevation of approximately 3,600 feet above sea level. Renovation of the dam and outlet structures and fish management procedures are discussed. Subsurface water temperatures and dissolved oxygen values were obtained during the summers of 1965 and 1966. These are discussed in relation to an aeration system installed during the fall of 1965. No definite conclusions concerning beneficial effects on the fishery were arrived at; although dissolved oxygen in bottom waters was higher during the summer in which the aeration system was in operation. The aeration did appear to be effective in removing ice from around the outlet tower. Rainbow trout, Salmo gairdneri, brook trout, Salvelinus fontinalis brown trout, Salmo trutta were introduced into the lake. Brook trout appeared to achieve a better growth rate than either of the other two species.

A detailed description of the procedure used in taking stream bottom samples follows a description of the stream square foot bottom sampler, which, although pictured in a publication by the author in 1937, was not described in detail in any publication. One of the principal problems in retrieving bottom animals from samples is getting them quickly from the gravel without damaging them. Large stones in the sample area are removed first and placed in a pail half-filled with water. The contents of the net are also emptied carefully into the same pail. Upon reaching the shore, the pail is filled with water. After washing and removal of the large stones which are placed where animals crawling from hiding places on them can be retrieved, a series of decantations are made into a U. S. Series No. 30 soil sieve 8 inches in diameter and 2 inches deep held in water above the screen surface.

Brackish water pond studies were conducted in coastal Southwest Louisiana with blue, lctalurus furcatus, channel, lctalurus punctatus, and white catfish, lctalurus catus, to determine if these freshwater species could be cultured in saline ponds. The channel and white catfish proved to be the most rapid growing and the most hardy, averaging 0.80 and 0.70 pounds. The blue catfish averaged 0.6 pound. The channel catfish had the lowest S-value of 2.3, the white catfish had a S-value of 2.9 and the blue catfish had as-value of 4.0. Survival was highest for channel catfish, 91 per cent, and lowest for the blue catfish, 69.6 per cent. The condition indexes, using standard length, calculated for the white, channel and blue catfish were 2.15, 1.70 and 1.49, respectively. Blue and channel catfish collected from surrounding waters had K values slightly less.

Bottom soil samples were taken after each draining during a five-year period from a series of 12 small earthen ponds ranging in size from 0.70 to 1.39 acres. Except in one pond, drainings occurred one or more times annually. The ponds were used to produce one or more crops of fingerling fish each year. Species cultured were largemouth bass, bluegill, channel catfish and redeal' sunfish. Chemical analyses for pH, calcium, phosphorus, potassium, carbon and nitrogen were done on each sample. All ponds except one were fertilized and supplemental feeding was done on a limited scale in some of the ponds. The quality of the water supply was a significant influence for modification of the parameters included, with artificial enrichment also appearing to exert an important effect. Generally, the soils became more alkaline and richer in calcium.

The effects of soil and water hardness on growth and survival of red swamp crawfish, Procambarus clarki, were studied in plastic pools. Pools had no soil or Calhoun soil, with water hardnesses adjusted with calcium chloride to 9, 50, 100 or 150 parts per million, or pools had Sharkey soil with water hardnesses of 50, 100, 150 or 200 ppm. Water hardness was the most significant factor affecting growth and survival of crawfish. As water hardness increased, so did the mean weight gain and per cent survival. At 9 ppm water hardness, the presence of soil resulted in similar weight gain per crawfish as in no-soil pools but crawfish survival in pools containing soil was 53 to 77 per cent and only 9 per cent in pools with no soil. Good growth of crawfish occurred in the absence of soil, if water hardness was high. The highest mean weight gain per crawfish and per cent survival were in pools containing Sharkey soil.

Biological and chemical-physical data were obtained from burrows of the red swamp crawfish, Procambarus clarki, and the adjacent ponds and ditch during the burrowing period. Burrows constructed by mature and immature crawfish were of the same general pattern. Burrows usually consisted of an undulating downward channel, varying in depth, devoid of a connection with the adjacent pond or ditch. The tunnel was covered by a chimney or mud plug at the top and was enlarged at its deepest part into a chamber. Variance in the diameter of the channel seemed correlated with the total bodylength of the inhabiting crawfish. Fauna present in burrow water consisted mainly of planktonic crustaceans. In general, the animal groups in burrows were similar to those present in the adjacent pond or ditch but fewer species and numbers occurred in the burrows.

Florida has comparatively few species of large predatory freshwater fishes. Many lakes of the state have an abundance of forage fishes. Therefore, niches may be available for additional desirable predatory species. As far as I know, there is no record of walleye (Stizostedion vitreum) occurring naturally as far south as peninsular Florida. People not familiar with walleye may have the mistaken impression they require cold, deep water. If this were so, an attempt to introduce them into Florida would be absurd. However, there is a strong superficial resemblance between many lakes there and warm, shallow Midwestern lakes that have good walleye populations. Because of this resemblance, I decided to see if walleye could survive in Florida. Permission was obtained to use a privately owned, dug pond, about 0.3-acre in size at Vero Beach, Florida (latitude 27 0 39'). Rotenone was applied for a complete kill, but no fish were found.