1999 Warmwater Fisheries Survey of Red Rock Lake, Grant County, Washington

Red Rock Lake, Grant County, Washington, was surveyed between October 7-29, 1999, using an electrofisher, gill nets, and fyke nets. A total of 10 fish species were observed during 1999: largemouth bass (Micropterus salmoides), smallmouth bass (M. dolomieu), black crappie (Pomoxis nigromaculatus), Yellow perch (Perca flavescens), pumpkinseed (Lepomis gibbosus), lake whitefish (Coregonus clupeaformis), brown bullhead (Ictalurus nebulosus), tiger muskellunge (muskies) (Esox lucius �" E. masquinongy), common carp (Cyprinus carpio), and sculpin (Cottus spp.) Warmwater gamefish comprised approximately 90 percent of the total fish captured. Yellow perch were the most abundant (52%) species sampled and carp accounted for the majority (67%) of the biomass.

Largemouth bass comprised 12 percent of the sample and ranged in age from 1 to 15 years. Of the stock length largemouth bass that were sampled (n = 95), 36 percent were of quality size and 21 percent were of preferred size. Largemouth bass ranged in total length from 111 to 545 mm and appeared to be in good condition (weight); few fish had relative weights less than 90. Relative weights of largemouth bass sampled in 1999 were similar to those found during a 1997 electrofisher survey.

Black crappie comprised 18 percent of the sample and ranged in age from 1 to 6 years. Total lengths of black crappie ranged from 130 to 359 mm and were longer than the Eastern Washington average at all ages. Of the stock length black crappie sampled (n = 190), 17 percent were of quality size and 11 percent were of preferred size. Black crappie were found in slightly below average condition; most fish greater than 160 mm had relative weights between 75 and 90.

Yellow perch ranged in age from 1 to 3 years. Total lengths of yellow perch ranged from 108 to 245 mm. Yellow perch were similar to black crappie in that they exhibited good growth (length) but poor condition. Few yellow perch had relative weights greater than 100. Growth and condition of yellow perch were similar in 1999 and 1997.

Tiger muskies have not appeared to reduce yellow perch abundance as intended, and stocking has been suspended as a result of the removal of the lake outflow standpipe by the Quincy Irrigation District.

Overall, populations of largemouth bass, black crappie, and yellow perch in Red Rock Lake appear to be doing well in terms of growth and reproduction and no regulation or management changes are recommended at this time. Development of a fish migration barrier is recommended to inhibit downstream movement of the tiger muskies in the lake. We recommend that periodic warmwater fish surveys be conducted to monitor the size structure and condition of the largemouth bass, black crappie, pumpkinseed, and yellow perch in Red Rock Lake.