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William R. Nelson

Publications and source records attributed to William R. Nelson.

8 recordsLinked to original sources
USGS1974

Age, growth, sexual maturity, and food of channel catfish in central Lake Oahe, 1968-69

Channel catfish, Ictalurus punctatus , were collected with gill nets, trawl, and trap nets at three localities in Lake Oahe for the study of year-class strength, growth in length and weight, age composition, sexual maturity, and food. Fish were recruited to all the collection gears at age II. Relatively strong year classes were produced in 1962, 1965, and 1966. Youngest fish were captured in the upper end of the Moreau River embayment, which apparently serves as a nursery area. Growth of age 0 fish was poor probably because the growing season was short; optimum spawning temperature were not reached until mid-summer. Growth of age II and older fish reached a peak in 1963 and declined rather steadily in 1964-68. Males began to mature at age VIII, and all fish of both sexes were mature at age XI. The diet changed from zooplankton to fish as channel catfish increased in length; aquatic insects (primarily chironomid larvae and pupae) were important foods for fish of all sizes. Fish less than 300 mm long selected large zooplankters -- Leptodora kindtii and Daphnia spp -- over smaller copepods. Larger channel catfish ate principally yellow perch, Perca flavescens .

Technical Paper↗
USGS1974

Evaluation of trawls for monitoring and harvesting fish populations in Lake Oahe, South Dakota

Trawls of various designs and sizes were compared to evaluate their use for monitoring and harvesting fish populations in Lake Oahe. Catches of a 10.7-m semiballoon trawl, selected to monitor changes in the fish populations from 1965 to 1970, showed a downward trend in the abundance of all species, except walleye; the decline was largest in the lower area of the reservoir with a slight increase in the upper area. Of two trawl designs tested, semiballoon trawls captured more fish per hour than high-rise trawls, and a 15.9-m semiballoon trawl with a 3.8-cm mesh cod end captured fish at the highest and most consistent rate. The size and species composition of fish caught in small-mesh trawls differed from those caught in trap nets. Trawl catches were too small to recommend or warrant their use as a commercial fishing gear, but the use of both small mesh trawls and trap nets should improve accuracy in monitoring fish populations in this reservoir.

Technical Paper↗
USGS1974

Age, growth, and maturity of thirteen species of fish from Lake Oahe during the early years of impoundment, 1963-68

The body-scale relation, calculated length, length-weight relation, age at maturity, and sex ratio of 13 major species collected in Lake Oahe from 1963 to 1968 with trap nets and bottom trawls are described. Eight species grew at a faster rate than has been recorded in other Missouri River reservoirs: goldeye ( Hiodon alosoides ), bigmouth buffalo ( Ictiobus cyprinellus ), smallmouth buffalo ( Ictiobus bubalus ), white bass ( Morone chrysops ), black crappie ( Pomoxis nigromaculatus ), white crappie ( Pomoxis annularis ), walleye ( Stizostedion vitreum vitreum ), and freshwater drum ( Aplodinotus grunniens ). Four species grew at rates similar to those recorded from other Missouri River reservoirs: carp ( Cyprinus carpio ), yellow perch ( Perca flavescens ), northern pike ( Esox lucius ), and sauger ( Stizostedion canadense ). One species -- river carpsucker ( Carpiodes carpio ) -- grew slower than in other waters. Growth generally was excellent for all major species in the early years of impoundment (1959-62) but then declined. Species showing the greatest decline in growth from 1962 to 1967 were goldeye, bigmouth buffalo, sauger, walleye, northern pike, and freshwater drum. As growth rate decreased, age at sexual maturity increased for northern pike, carp, river carpsucker, bigmouth buffalo, and freshwater drum. Although inundation of new lands was associated with rapid growth of fishes in the early years of impoundment, water level fluctuations during the growing season had no discernible effect on growth rate. Increased average reservoir depth, which decreased the amount of littoral area, was associated with decreased fish growth.

Technical Paper↗
USGS1974

Goldeye, Hiodon alosoides, in Lake Oahe: abundance, age, growth, maturity, food, and the fishery, 1963-69

Reproductive success was relatively consistent, and adequate to maintain species abundance at a nearly constant level, during 1963-69. Both abundance and growth in length increased from the lower to the upper portion of the reservoir. In most characteristics -- growth in length, length-weight relation, age at maturity, and food -- goldeye in Lake Oahe were similar to those from other Missouri River impoundments. Experimental gill nets samples all lengths (range 80-460 mm; median, 320 mm) of goldeye, bottom trawls sampled mostly small fish, (median, 215 mm) and trap nets large ones (median, 345 mm). Commercial gill nets were highly size selective (median, 375 mm); fish of ages IV-VII made up 90% of the catch. Survival rates were 57 to 52% for ages II-X. Estimated survival rates for ages V-IX declined from 44 to 35% after the inception of the commercial fishery in 1966. The peak commercial catch was 151,432 kg (1.2 kg/hectare) in 1969. Unless recruitment declines, the population can support a fishery of that magnitude.

Technical Paper↗