The Washington Department of Fish and Wildlife Program will be conducting a fisheries survey at Angle Lake from Sept. 19-30, the City of SeaTac announced this week.
This survey will allow biologists to assess the fish community and long-term changes in response to the recent unauthorized introduction of Walleye Sander vitreus into the lake. The WDFW is concerned that this introduction will drastically reshape the fish community and depress, or eliminate, existing fisheries in Angle Lake.
WDFW fish surveys incorporate multiple capture gears (boat electrofishing, gill nets and trap nets) to gather an accurate representation of the fish community. Boat electrofishing surveys will begin at sundown at least two evenings during this period. The boat is equipped with bright lights and a generator that can at times be loud.
This type of sampling utilizes electrical current to temporally stun fish, which allows biologists to easily net them. Fish rarely die during this capture method. Biologists will try to conclude boat electrofishing before midnight to minimize disturbance to lake residents.
Overnight gill and trap netting will also be conducted multiple times during this period. Nets will be deployed in the evening and retrieved the following morning. There is some mortality associated with netting, especially in gill nets. This is unfortunate, but gill nets are the most successful gear at capturing species like Yellow Perch Perca flavescens and Walleye.
Captured fish kept alive in an onboard tank with circulating water. Biologists will quickly measure, weigh and remove one ventral fin to identify individuals that are recaptured during the survey. Any fish that die during the survey will be returned to the lake.