Determination of Striped Bass Spawning Locations in the Two Major Tributaries of Lake Texoma

Abstract

Even though Lake Texoma is one of only four reservoir systems in the southeastern United States with a reproducing population of striped bass Morone saxatilis, spawning locations have not been determined. Recently proposed water development projects in the watershed make locating and protecting these locations a priority. The objectives of this study were to (1) determine where and when striped bass spawn in the Red and Washita rivers, (2) compare the relative densities of striped bass eggs collected in the two rivers, (3) determine the horizontal distribution of striped bass eggs in the Washita River, and (4) assess water-chemistry-related differences in the size of striped bass eggs between the two rivers. Striped bass eggs were classified into developmental stages and assigned ages (in hours) based on developmental temperature. Spawning areas were predicted from egg age and river current velocity as well as the presence of suitable habitat (verified visually). Striped bass spawning peaks generally followed stage rises in both rivers. Striped bass eggs were collected from 4 April to 18 May, 2001, in the Red River and from 3 April to 19 May, 2001, in the Washita River. Mean egg density peaked at 5 eggs/m³ on 16 April in the Red River and at 34.4 eggs/m³ on 21 April in the Washita River. We found no relationship between spawning distance from the lake and discharge. Direct comparison of egg catches in the two rivers may be misleading due to differences in channel morphology. However, in the Washita River, we found no horizontal difference in egg density across the river channel. Management agencies should exercise caution with respect to the implementation of water development projects within the watershed that could alter river flow or water chemistry, as these are probably key to the continued reproductive success of striped bass in the Lake Texoma system.