1997 Loomis Lake Survey: A Coastal Warmwater Fish Community before Implementation of an Aquatic Plant Management Plan

Loomis Lake is a long (6.9 km), narrow eutrophic body of water which runs parallel to Washington’s coast on the Long Beach Peninsula in Pacific County. The shallow lake (mean depth = 1.5 m; max depth = 2.7 m) is fed by rainfall and groundwater. Surface water exits the lake (surface area = 68 ha) through an unnamed creek at the far north end, eventually discharging into the Pacific Ocean. Dense stands of emergent burreed (Sparganium sp.) surround most of the lake, whereas spatterdock, or yellow waterlilly (Nuphar polysepala), is patchily distributed at the north and south ends. The predominant submerged aquatic plants include flat stemmed pondweed (Potamogeton zosteriformis), waterweed (Elodea canadensis), coontail (Ceratophyllum demersum) and, unfortunately, invasive Eurasian watermilfoil (Myriophyllum spicatum). Details of these and other characteristics can be found in a 1998 draft report prepared by Envirovision Corporation (Debra Bouchard; personal communication) and through the Washington Department of Ecology (Kirk Smith; personal communication). Development on the lake is minimal. The western shoreline has few private homes, whereas most of the eastern shoreline, which is owned by the Washington Parks Department, remains completely natural. Recreational activities include both warmwater and trout fishing (the lake is stocked annually with rainbow trout (Oncorhynchus mykiss), swimming, small water craft use, and wildlife viewing. The Washington Department of Fish and Wildlife (WDFW) maintains a public access and boat launch located mid-lake on the western shore.

In recent years, Long Beach Peninsula residents have expressed concern about the invasion of the lake by Eurasian watermilfoil and the spread of the nearshore burreed. Accordingly, the Loomis Lake Group was convened in 1996 to address the matter. By the fall of 1997, an aquatic plant control plan was developed by a private contractor and presented to the group for approval (Envirovision in review). The January 1998 draft of the Loomis Lake Integrated Aquatic Plant Management Plan, which was largely funded by the Aquatic Weeds Program of the Washington Department of Ecology and the Pacific Conservation District, recommended applications of the herbicides Sonar^® and Rodeo^™ to control the spread of nuisance aquatic plants in Loomis Lake.

Although much information exists regarding the community structure of aquatic plants at Loomis Lake (Parsons in press), including that gathered for the plan above, there is no current information regarding the status of aquatic animals, i.e., the fish community. Given its physical characteristics, Loomis Lake is well suited for warmwater fish species. Therefore, in order to evaluate the fish populations of Loomis Lake before implementing the aquatic plant control plan, personnel from WDFW’s Warmwater Enhancement Program conducted a survey of the lake during the late summer of 1997.