OLYMPIA – Washington Department of Fish and Wildlife (WDFW) biologists will take to Lake Washington in more than half a dozen boats beginning June 27 to sample the lake’s resident fish population over four consecutive nights.
Data collected during the survey will help biologists determine the population status of the lake’s resident fish community, said Chad Jackson, WDFW fisheries biologist and survey co-coordinator. This marks the first major survey of Lake Washington’s resident fish population in nearly two decades.
“We haven’t sampled Lake Washington’s fish population for a long time, and this survey will provide us with a great amount of valuable data,” Jackson said. WDFW is funding the work.
Biologists will use three sampling methods to collect fish from the lake, including netting, live trapping and electrofishing. All of the work will begin at dusk and run through the night. Sampling occurs during the evening hours because a greater number of fish are present along the shoreline and are more active at night.
Monofilament nets and live traps will be set perpendicular to the shore at sunset. Both gear types will be clearly marked with WDFW floats, and fish caught in the gear will be collected in the early morning.
WDFW will also use eight electrofishing boats that create a small electrical field in the water to temporarily stun fish until they can be collected by research staff with dip nets in the bow of each boat. The fish are safely returned to the lake after the data is collected.
Although the electrical field extends less than 20 feet from each boat, Jackson says that parents should keep their children and pets out of the water in the vicinity of the research boats.
“Because we are using electrical equipment in the water, anyone who is interested in the research should view our work from the shore,” Jackson said.
All three sampling methods are needed because one gear type will capture certain fish species more effectively than others, said Steve Caromile, WDFW warmwater stock assessment biologist and the survey’s co-coordinator.
“If we were to use only one method, we could potentially miss a segment of the resident fish community, and our data would be incomplete,” Caromile said, adding that approximately 40 percent of the lakeshore will be sampled during the survey.
Warmwater Fish Enhancement Program biologists will analyze and summarize the data and publish the findings in a technical report, which will be available next spring.
With an area of about 21,500 acres, Lake Washington is the second-largest natural lake in the state. The lake contains a number of fish species, including chinook, coho and sockeye salmon, cutthroat trout, largemouth and smallmouth bass, yellow perch, pumpkinseed sunfish, sculpin, stickleback, suckers and northern pikeminnow.
More information on WDFW’s Warmwater Fish Program is available at http://wdfw.wa.gov/fish/warmwater/ on the Internet.
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