1997 Lacamas Lake Survey: The Warmwater Fish Community of a Highly Eutrophic Lowland Lake

Lacamas Lake is a narrow, moderately deep (mean and maximum depth = 7.1 and 19.8 m, respectively) body of water located in Clark County just north of the City of Camas and 16.1 km east of the City of Vancouver, Washington. The lake is fed by Lacamas Creek from the north and runoff from the surrounding foothills. Surface water exits Lacamas Lake at the southern end, through Round Lake via Lacamas Creek, eventually discharging into the Washougal River. Although the lake’s origin is natural, it was enlarged (present surface area = 123.3 ha) during the latter part of the 19th century with the construction of two downstream dams. Since 1936, the outflow from Lacamas and Round Lakes has been controlled and regulated by the Fort James Corporation (formerly Crown Zellerbach), which operates the dams and a paper mill at the south end of Round Lake (Beak/SRI 1985).

Lacamas Lake is highly eutrophic and has experienced water quality problems for years. Heavy nutrient loads (nitrogen and phosphorous) from farms and failed sewage systems along Lacamas Creek and its tributaries contribute to nuisance algal blooms by species that favor the eutrophic conditions. Nutrient concentrations and algal growth rates cause extreme diurnal swings in pH which can be harmful to fish. Furthermore, during the warmer spring and summer months, the lake readily stratifies. Consequently, decomposition of plankton creates a hypoxic, inhospitable environment for fish and other aquatic animals in the lake’s hypolimnion (Beak/SRI 1985; ESEC 1998). Past proposals to rectify the situation included implementation of improved waste disposal and handling techniques, and hypolimnetic aeration (Beak/SRI 1985). In recent years, agricultural best management practices sponsored by the Clark County Public Works’ Lacamas Lake Restoration Program were successful in reducing the nutrient input to Lacamas Creek (Bachert and Hutton 1995), whereas limited resources and, to a lesser degree, water safety issues, precluded installing a hypolimnetic aerator at Lacamas Lake (Jeff Schnabel, Clark County Public Works, personal communication).

Although the Lacamas Lake Restoration Program has been effective in improving the water quality of Lacamas Creek, recent studies and a review of the program’s activities suggest that there has been no improvement in the lake’s water quality since the mid-1980's (ESEC 1998). According to ESEC (1998), the Lacamas Lake Restoration Program should be �"redirected to focus on improving and maintaining conditions in the lake that will support appropriate beneficial uses desired by the community rather than striving for some historical pristine condition.” Fishing has been identified as the main use of Lacamas Lake (Beak/SRI 1985). Other recreational activities include water skiing and jet skiing. For 60 years, the Washington Department of Fish and Wildlife (WDFW; formerly Washington Department of Game) has managed the lake as a trout fishery. Rainbow trout (Oncorhynchus mykiss) have been stocked intermittently since 1938, whereas brown trout (Salmo trutta) were first stocked in 1980 (John Weinheimer, WDFW, unpublished data). However, a previous study by WDFW (Fletcher 1981) indicated that Lacamas Lake was well suited for warmwater fish species. Therefore, in an effort to assess the warmwater fishery of the lake, as well as to monitor the success of the restoration plan, personnel from WDFW’s Warmwater Enhancement Program conducted a fisheries survey at Lacamas Lake in summer 1997.