Letter and pictures submitted by Mike Biggs, conductor of the study
“A research project studying Columbia River redband rainbow trout in Twin Lakes, Washington, is being conducted this year. This study involves personnel from Washington State University (WSU) and the Colville Confederated Tribes (CCT). Introductions of nonnative fish and water quality conditions have created concerns for the trout fishery in Twin Lakes. In 2006, the CCT stocked a small number of ultrasonically tagged redband rainbow trout into Twin Lakes. Our goal was to determine the horizontal and vertical movements of these fish, and to relate their movements and habitat preferences to environmental conditions.
Redband trout tracking demonstrated extensive daily movements along shorelines and across the lakes, with long periods of inactivity at night. Trout remained in a narrow band of habitat near the thermocline throughout the summer. Our preliminary results suggest improving water quality, to enhance summer trout habitat, may need to be addressed to provide a long-term trout fishery.
We used depth and coded transmitters, and the MANTRAK to determine fish location and movements. We found the equipment very reliable and user friendly. Sonotronics service was excellent and provided timely delivery of products and customer satisfaction. We appreciate their cooperation and willingness to help us with our research.”