2005 Warmwater Fisheries Survey of Stan Coffin Lake, Grant County, Washington

Stan Coffin Lake was surveyed by the Region Two Warmwater Team September 7-8, 2005 using standardized warmwater survey methods. This is the fifth year of surveys conducted to determine long-term trends in this fishery. The most abundant species collected was pumpkinseed sunfish (Lepomis gibbosus), closely followed by bluegill (L. macrochirus), and largemouth bass (Micropterus salmoides). Yellow perch (Perca flavescens), black crappie (Pomoxis nigromaculatus), channel catfish (Ictalurus punctatus), smallmouth bass (M. dolomiteu), and prickly sculpin (Cottus asper) comprised the remainder of the fish collected. Yellow perch, pumpkinseed sunfish, black crappie and largemouth bass increased in our samples since 2004, while bluegill, and channel catfish declined over the same period. Relative weights were near the national average (Wr = 100) for all species with the exception of yellow perch. From 2001-2004, yellow perch declined in relative abundance, while bluegill increased. Black crappie relative abundance remained relatively unchanged from 2001-2004, while largemouth bass decreased in our samples from 2001-2003, yet increased significantly in 2004.

A population estimate on largemouth bass > stock length in Stan Coffin Lake was conducted in fall 2005 to establish baseline data for correlations between electrofishing catch-per-unit-effort, and population size, and to determine effects of predator densities on populations of panfish. The population of largemouth bass > eight inches in Stan Coffin Lake was 1,597 (95% CI; 1,307- 2,136); resulting in a density of approximately 40 fish per acre.