The Warmwater Fish Community of Lake Roesiger, with Notes on its Fisheries History

The Warmwater Enhancement Program conducted a stock assessment of fish species in Lake Roesiger in late spring of 1999, because of its historical importance to recreational fishing, increasing interest in warmwater fishing there, and paucity of recent warmwater species data. Warmwater fish species, especially yellow perch, dominated our catch. Growth of largemouth bass, black crappie, pumpkinseed and yellow perch was consistent with or above western Washington state averages. However, CPUE for largemouth bass, black crappie and pumpkinseed were below average, suggesting lower abundance of these species. Obvious gaps in the length frequency distribution of these species may be due to weather-related year-class failure, competition with the abundant yellow perch, or overharvest of larger individuals. However, interaction of our gear with spatial and temporal distribution of fish cannot be ruled out. The largemouth bass population in Lake Roesiger appears robust, as evidenced by rapid growth rates, strong PSD values, and relative weights consistent with other western Washington State waters. However, a more regulated fishery could protect and enhance the structure and abundance of this population. Based on our assessment of the warmwater fish community of Lake Roesiger, enhancement options discussed include implementing a slot limit on largemouth bass to improve their size structure as well as introduction of non-reproducing channel catfish to control the overabundant yellow perch population and provide additional fishing opportunity.