Abstract
Fish communities in 11 Soil Conservation Service floodwater retarding structures were studied to determine factors associated with variations in largemouth bass abundance and standing crop over a 15-month period. Petersen population estimates and biomass estimates for largemouth bass in fall 1979, spring 1980 and fall 1980 were compared with concurrent electrofishing, bag seine and gillnet catch data using Spearman rank correlation. Numbers per hectare of small (175-249 mm) and large (> 249 mm) bass in fall 1979, ranged from 6-1068 and 6-107 respectively. Numbers per hectare of small (< 250 mm) and large (> 249 mm) bass respectively in subsequent samples were as follows: spring 1980--9.1-1309.9 and 5.7-205.7; fall 1980--10.1-391.6 and 1.4-81.4. Biomass estimates (kg/ha) for small and large bass respectively ranged from 0.5-71.6 and 4.2-49.9 for fall 1979; 0.6-63.5 and 5.3-1000.3 for spring 1980; and 1.1-21.6 and 0.8-32.4 for fall 1980. Means of overall best estimates of biomass were 15.2 kg/ha for small fish and 16.6 kg/ha for large fish. Variations in bass abundance and standing crop were the result of fluctuations in recruitment. Abundance of small bass was greater in clear lakes. High spawning success was found in lakes with high abundance of large bass. Growth of young bass was density dependent, limited by forage availability and negatively correlated with water transparency. Abundance of these bass was correlated to abundance and size structure of other species. Inverse correlations with white crappie abundance suggested that predation by white crappie limited recruitment. Poor success of the 1980 year-class was probably due to heavy predation when water levels were low. Total bass biomass was highest in lakes with 40-60% bass proportional stock density (PSD). Abundance of large bass was correlated with diverse size structure of other species. Total bass biomass and PSD of bluegill and channel catfish were positively correlated. Bass PSD and PSD of bluegill, channel catfish and white crappie exhibited a non-linear relationship. A standing crop 20 kg/ha of large bass was necessary to adequately control abundance of other species. Bass populations in floodwater retarding structures could be improved through modification of structure design, proper stocking, habitat management to improve water clarity and controlled harvest.
Brenner, Blair Christia (1983). Variations in largemouth bass abundance and standing crop in floodwater retarding structures in central Texas. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -577013.