2001 Warmwater Fisheries Survey of Lake Spokane, Spokane and Stevens Counties, Washington

A littoral zone survey coordinated by the Washington Department of Fish and Wildlife, of Lake Spokane (Long Lake), Spokane County, Washington, was undertaken by seven 3-person teams June 18-22, 2001, using boat electrofishers, gill nets, and fyke nets. The limnetic zone of the reservoir was surveyed by a 3-person team using hydroacoustics in conjunction with vertical and horizontal gill nets. The inshore survey was conducted to assess growth, condition, reproduction, and survival of warmwater gamefish in Lake Spokane whereas the offshore component evaluated composition, distribution, and abundance of limnetic fish species. During the inshore survey, a total of 21 fish species were observed. Largescale sucker (Catostomus macrocheilus) were most abundant (n=1,535) in the inshore samples and accounted for the majority of the biomass (49.5%). Yellow perch (Perca flavescens) were the most abundant gamefish sampled (n=1,108) inshore. Largemouth bass (Micropterus salmoides) ranged in age from 2 to 13 years but comprised only 2.3% of the inshore sample. Smallmouth bass (M. dolomieui) comprised approximately 8.5% of the inshore sample and ranged in age from 1 to 7 years. Eleven species were observed during offshore sampling, including kokanee (Oncorhynchus nerka) and chinook salmon (O. tshawytscha) not observed inshore. Northern pikeminnow (Ptychocheilus oregonensis) was the most abundant species sampled (n=139) offshore and comprised most of the biomass (49.3%). Similar to the inshore sampling, yellow perch were the most abundant gamefish sampled (n=111) during offshore sampling. Overall results of this survey were similar to studies in the late 1980s and indicate that Lake Spokane supports quality populations of largemouth bass, yellow perch, and black crappie (Pomoxis nigromaculatus). Since their introduction in the early 1990s, smallmouth bass have established as a self-sustaining population within the reservoir. Largemouth bass recruitment in Lake Spokane appears limited, possibly due to factors including inadequate habitat, competition, predation, and reservoir operations. Although trend data is lacking, low recruitment of largemouth bass may benefit the overall quality of Lake Spokane’s largemouth bass population by limiting competition. Information collected during this survey was used to identify possible management strategies that would improve the quality of fishing in Lake Spokane. Future management considerations include monitoring the response of fish populations to the recently imposed slot-limit on largemouth and smallmouth bass, continued evaluation of the seasonal catch-and-release bass regulation, conducting a creel survey to determine angler harvest, and determining what factors are limiting condition of adult black crappie in the reservoir.