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Theresa "Marty" Liedtke

Marty Liedtke is a Project Leader at the Columbia River Research Laboratory with 25+ years of experience focused on movement, behavior, and performance of fishes in both freshwater and marine systems.

My research is currently focused on Pacific Lamprey and other native lampreys in the Columbia River Basin and forage fishes in Puget Sound.  My team evaluates juvenile and larval lamprey performance under controlled laboratory conditions to address management needs such as dewatering of lamprey habitat, interactions with screens at water diversions, and dredging impacts. A newly developed, prototype acoustic telemetry transmitter, designed for use in lamprey and eels allowed us to conduct one of the first acoustic telemetry studies of juvenile Pacific lamprey migration movements. Prior to the development of this transmitter such studies were not possible due to the small size of these fish. In Puget Sound we have focused on Pacific sand lance and surf smelt and have evaluated spawning site selection, responses to climate change, food habits, and rearing habitats. Most recently we are investigating linkages between forage fishes and legacy and current use contaminants in both field and laboratory settings. 

Historically my team has conducted radio and acoustic telemetry studies to evaluate juvenile salmon passage and survival at hydroelectric dams in the Columbia River Basin.  We have used telemetry to monitor the behavior and movements of many fishes, including adult salmonids using transmitters with sensors (temperature, motion). I have developed standard operating procedures for surgical implantation of transmitters and regularly train others to design tagging operations and conduct tagging for telemetry studies. I am interested in the performance of fish equipped with telemetry transmitters, specifically comparing the stress response, swimming performance, buoyancy compensation, and predator avoidance ability of tagged fish to untagged fish.