Daily Fish and Zooplankton Abundances in the Littoral Zone of Lake Texoma,Oklahoma-Texas,in Relation to Abiotic Variables

Many studies have shown the effects of yearly or monthly environmental conditions on the structure of fish and zooplankton communities. Environmental conditions can also vary greatly on much shorter time scales. We tested the effects of abiotic conditions on the daily abundance of fish and zooplankton in the littoral zone of Lake Texoma, Oklahoma-Texas. After date was removed statistically from the analysis, no environmental variables were particularly important in determining the daily abundance of zooplankton, whereas, numbers of fish in the littoral zone were related to changes in wind velocity and wave height. Regressions of daily fish abundance against wave height showed that the response differed among species and among life-history intervals within species. Numbers of juvenile Dorosoma petenense, Notropis atherinoides, and Morone chrysops were positively correlated with wave height, whereas juvenile Menidia beryllina were negatively correlated with wave height. We suggest that changes in the abundance of particular species may be associated with (1) avoidance of inshore areas to escape possible physical damage by wave induced turbulence, (2) attraction to inshore areas to feed on prey organisms suspended in the water column by wave induced turbulence, and (3) avoidance of inshore areas to escape high predator abundance and increased possibility of being eaten due to turbulence.