2000 Warmwater Fisheries Survey of Newman Lake, Spokane County, Washington

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Published: March 2004

Pages: 47

Publication number: FPT 04-02

Author(s): Randall S. Osborne, Heather Woller, and Marc Divens

Newman Lake was surveyed by a 3-person investigation team September 18-20, 2000. Fish were sampled by boat electrofishing, gill netting, and fyke netting. Twelve fish species were collected. Yellow perch (Perca flavescens) (n=923), bluegill sunfish (Lepomis macrochirus) (n=237), and largemouth bass (Micropterus salmoides) (n=208) were the most abundant gamefish species observed during collection activities. A large proportion (39.5%) of the biomass was comprised of common carp (Cyprinus carpio). Black crappie (Pomoxis nigromaculatus), pumpkinseed sunfish (L. gibbosus), yellow bullhead (Ameiurus natalis), brown bullhead (A. nebulosus), smallmouth bass (M. dolomieu), tench (Tinca tinca), tiger muskellunge (Esox lucius x E. masquinongy), and rainbow trout (Oncorhynchus mykiss) were also collected. Newman Lake shows indications of having a prey-crowded fish community dominated by yellow perch and bluegill sunfish less than quality size. Although largemouth bass are also fairly abundant in the lake, most are small (<200 mm). The relatively low condition of bluegill sunfish, pumpkinseed sunfish, yellow perch, and smaller size largemouth bass indicates that largemouth bass are having to compete with their forage rather than prey upon them. The low stock density values and slow growth rates of yellow perch, bluegill sunfish, and pumpkinseed sunfish suggest that predation rates on those species by largemouth bass, smallmouth bass, and tiger muskellunge are insufficient to control stunting.

Due to measures taken by the Washington State Department of Ecology, including the operation of a hypolimnetic aerator and alum injection system by the Spokane County Division of Engineering and Roads, Newman Lake water quality has improved since the mid-1990s. Although late summer dissolved oxygen may drop below levels preferred by most fish species, the results of this survey suggest that those effects on fish populations in Newman Lake have been minimal, and water quality monitoring, the operation of the hypolimnetic aerator and alum injection system should continue. Future management considerations include increasing the annual stocking rate of tiger muskellunge, monitoring the response of fish populations to the recently imposed largemouth and smallmouth bass slot limit, conducting a creel survey to determine angler harvest and preferences, and determining what factors are limiting condition of adult black crappie in the lake. In addition, enhancement of the WDFW access site to include a boat dock and a fishing pier is recommended.