Analysis of Stocking and Harvest Variables in Earthen Florida Largemouth Bass Fingerling Rearing Ponds

Kurten, G., Texas Parks and Wildlife Department, Inland Fisheries, A. E. Wood Fish Hatchery, 507 Staples Road, San Marcos, Texas 78666

Six years (1992-1997) of data from 197 Florida largemouth bass (Micropterus salmoides floridanus) rearing ponds was analyzed to examine the relationships between fingerling harvest variables and fingerling stocking variables and zooplankton densities. Fish growth was the most reliably predicted harvest variable (r² =0.44). Growth was adequate to produce 38-mm fingerlings at maximum fish stocking densities of 690,000 fish/ha only if Cladoceran and Copepod densities were at the highest values for the dataset. Fish survival increased with fry stocking size. The optimum stocking size to provide 60% survival of fingerlings was about 20 mm. Harvest biomass and harvest length appeared to be improved by lengthening the interval between pond filling and fish stocking. Harvest density was improved by increasing one indicator of fish stocking size; stocking biomass and by increasing stocking densities. Survival seemed to be a poor indicator of production success because, while survival rates decreased with stocking density, actual harvest densities increased. Zooplankton densities at stocking and at seven days after stocking were, generally, weak indicators of harvest variables. However, Cladoceran and Copepod nauplii densities at stocking and Rotifer densities at seven days after stocking appeared to be significant indicators of fish production success. The low correlation of fish production and zooplankton variables and the indication that lengthening the pond filling to stocking interval improves harvest biomass and harvest length seem to indicate that managing for immigration and development of other, larger pond invertebrates may improve fish production above managing for zooplankton alone when the target production size for Florida largemouth bass fingerlings is 38 mm.

Copyright © 1999
Texas Chapter of the American Fisheries Society
Last modified: 03/03/04 04:15:38 PM