Theresa "Marty" Liedtke

Marty’s research interests with lamprey are coordinated with the Pacific Lamprey Conservation Initiative (PLCI).  The PLCI is a collaboration of Native American tribes, federal, state, and municipal agencies and non-government organizations in the Pacific Northwest working to conserve Pacific Lamprey and their habitats. USGS is a signatory on the PLCI Conservation Agreement and Marty represents the agency on the Conservation Team and shares her expertise on multiple Technical Workgroup committees. Marty’s research aligns with PLCI priorities, is commonly supported by PLCI funding, and engages a range of tribal partners. Her primary area of interest is lamprey responses to stressors such as dewatering, salvage efforts, dredging, or screen interactions. 

Larval lamprey are filter feeders that live burrowed in stream sediments for up to 10 years before they transform into juvenile and migrate to the ocean. Their habitats are frequently dewatered as stream flows decline or reservoir elevations are artificially manipulated, and such events can kill thousands of lamprey. Prior to Marty’s work in the laboratory, little was known about how lamprey respond when their habitat is dewatered, so managers lacked the information they needed to limit negative impacts. Her body of work on this topic is recognized as foundational and has been used to support best management practices for in-water work and dredging operations. 

Early in her career, and continuing alongside her lamprey research, Marty used telemetry techniques to monitor the movements, survival, and passage of juvenile salmon in the Columbia River Basin. She helped develop and refine the procedures for surgical implantation of transmitters, has trained surgeons from a wide range of agencies and is recognized as an expert on the topic. She studied stress response and fish performance and applied those findings to refine the tagging techniques. 

Marine forage fishes and nearshore marine ecology are additional areas of research. Working on a USGS interdisciplinary team Marty investigated movements of forage fish, the selection of beaches for spawning, use of eelgrass habitats, and contaminant exposures and tissue burdens.