Willy Eldridge

William H. Eldridge Ph.D.

Adjunct Scientist

970 Spencer Road

Avondale, PA 19311


Principal Investigator of the Fish Molecular Ecology group

Research Interests

My research is concerned with understanding and conserving the genetic diversity that is necessary for fish —from individuals to species and entire populations — to adapt to changing environments, thus ensuring their long-term survival.


Ph.D., 2007, University of Washington, Fishery Sciences (Certificate in Environmental Management). 

M.S.,  2000,  University of Minnesota, Fisheries.

B.S., 1995, Haverford College, Biology.

Previous Positions

Lecturer, TESC 434: The history, biology and politics of salmon in the Pacific Northwest, University of Washington, Tacoma. 2007.

Fishery Geneticist II, Northwest Indian Fisheries Commission, Olympia, WA. 2000–2003.

Scientific Consultant, Sustainable Fisheries Foundation, Bothell, WA. 2000.

Current & Recent Research

Program name: Evaluating the seasonal effects of short-term temperature change on macroinvertebrates and fish in streams and rivers.

Project duration: two years (2007-2009)

Description: Laboratory studies to evaluate the response of fish and macroinvertebrates to variable rates of temperature change (warming or cooling) during a 24 h period. Study parameters include survivorship, growth, metabolism, tissue integrity, and blood chemistry of twelve species (6 fish and 6 macroinvertebrates) measured during winter and summer. Monitoring a number of bioenergetics and physiological responses will help to elucidate the relative importance of temperature change to the fish and macroinvertebrates. Identifying the rate of temperature change at which no sublethal stress response is found will help guide efforts to manage streams and rivers in ways that avoid negative impacts to macroinvertebrate and fish populations.

Principal investigators: Bernard Sweeney, Willy Eldridge, John Jackson

Program name: Effects of translocations on fine-scale population structure in coho salmon of Puget Sound, Washington

Funded by: National Marine Fisheries Service
Project duration: six years (2001-2007)

Description: Examine the effects of historical hatchery practices on native populations of Coho Salmon in Puget Sound, Washington. Until recently, Coho salmon in Puget Sound were moved extensively for culture and enhancement purposes but no monitoring has been done to examine the effects of these transfers on the flow of genetic material among native populations. This project will help guide future management of Coho and other salmon species, as well as reveal useful insight into the biology of this commercially and recreationally significant species. Collaborators include biologists with the Northwest Indian Fisheries Commission and Western Washington Tribes, the Washington Department of Fish and Wildlife, and National Marine Fisheries Service.

Program name: Demographic effects of harvest induced evolution in Pacific salmon

Funded by: National Marine Fisheries Service & National Sea Grant
Project duration: two years (2005-2007)

Description: Selection due to fishing will be modeled using a novel approach combining a quantitative genetics model and a population dynamics model to examine the effects of selective harvest on the evolution of quantitative traits and fitness in salmon populations. This project will contribute to understanding the long-term effects of harvest on the dynamics of wild populations, and will help managers better identify long-term sustainable harvest strategies. This research is being conducted in collaboration with Jeff Hard of the National Marine Fisheries Service.


Eldridge, W., J. Hard and K. Naish. In press. Simulating fishery-induced evolution in Chinook salmon: the role of harvest gear, location and genetic correlations among life history traits. Ecological Applications.

Eldridge, W. H., J. M. Myers, and K. A. Naish. 2009. Long-term changes in the fine-scale population structure of coho salmon populations (Oncorhynchus kisutch) subject to extensive supportive breeding. Heredity. DOI: 10.1038/hdy.2009.69

Hard, J., W. Eldridge, and K. Naish. 2009. Genetic consequences of size-selective fishing: implications for viability of Chinook salmon in the Arctic-Yukon-Kuskokwim Region of Alaska. In: Sustainability of the Arctic-Yukon-Kuskokwim Salmon Fisheries. AFS Syposium 70: 759-780.

Eldridge, W. and K. Killebrew. 2008. Genetic diversity over multiple generations of supplementation: an example from Chinook salmon using microsatellite and demographic data. Conservation Genetics. 9:13-28.

Eldridge, W. and K. Naish. 2007. Long-term effects of translocation and release numbers on fine scale population structure among coho salmon (Onchorhynchus kisutch). Molecular Ecology. 16:2407-2421.

Eldridge, W., M. Bacigalupi, I. Adelman, L. Miller, and A. Kapuscinski. 2002. Determination of relative survival of two stocked walleye populations and resident natural origin fish by microsatellite DNA parentage assignment. Canadian Journal of Fisheries and Aquatic Sciences. 59:282-290.

Ghosh S, et al. 2000. The Finland-United States Investigation of Non-Insulin-Dependent Diabetes Mellitus Genetics (FUSION) study. I. An autosomal genome scan for genes that predispose to type 2 diabetes. American Journal of Human Genetics 67:1174-1185.

Watanabe RM, et al. 2000. The Finland-United States Investigation of Non-Insulin-Dependent Diabetes Mellitus Genetics (FUSION) study. II. An autosomal genome scan for diabetes-related quantitative-trait loci. American Journal of Human Genetics 67:1186-1200.

Ghosh, S., et al. 1999. Type 2 diabetes: Evidence for linkage on chromosome 20 in 716 Finnish affected sib-pairs. Proceedings of the National Academy of Science, USA. 96(5): 2198-2203.

Ghosh S., et al. 1998. A large sample of Finnish diabetic sib-pairs reveals no evidence for a non-insulin dependent diabetes mellitus susceptibility locus at 2qter. Journal of Clinical Investigations. 102(4): 704-709.

Ghosh S., et al. 1997. Methods for precise sizing, automated binning of alleles and reproduction of error rates in large-scale genotyping using fluorescently-labeled dinucleotide markers. Genome Research. 7:165-178.

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Recent Presentations

Eldridge, W., K. Naish, J. Hard. Fishery-induced evolution in Chinook salmon: the role of harvest gear, location, and genetic correlations among life history traits.  Six Decades of Fishery Genetics: A Retrospective View and a Vision for the Future. Seattle, WA. September 17-18, 2007.

Eldridge, W., K. Naish, J. Hard. Population viability of Chinook salmon following harvest selection. The Sixth William R. and Lenore Mote International Symposium in Fisheries Ecology: Life History in Fisheries Ecology & Management. Sarasota, FL. November 13-16, 2006.

Eldridge, W., K. Naish, J. Hard, and N. Hurtardo. Potential for domestication selection on egg size and number in Chinook salmon captive breeding programs. American Fisheries Society National Meeting. Lake Placid, NY. September 10-14, 2006.

Eldridge, W., K. Naish, and J. Myers. What about the coho? Genetic diversity in Puget Sound following transfers.  West Coast Salmon Genetics Conference. Santa Cruz, CA. June 22-24, 2006.

Eldridge, W., J. Hard, and K. Naish. An assessment of population viability of Chinook salmon in the Pacific Northwest following anthropogenic selection on fitness. Annual Meeting of the NMFS-Sea Grant Population Dynamics Fellows. La Jolla, CA. March13-14, 2006.

Eldridge, W. Decadal changes of genetic diversity of coho salmon in Puget Sound. Puget Sound Georgia Basin Research Conference. Seattle, WA. March 2005.

Eldridge, W. Interpreting Fst, a measure of genetic distance. West Coast Salmon Genetics Conference. Newport, OR. June 2004.

Eldridge, W. Genetic diversity of two species of hatchery supplemented Pacific salmonids over time. Fish Conservation Genetics Workshop. Sandbjerg, Denmark. September 2003.

Eldridge, W., M. Bacigalupi, and A. Kapuscinski. Parentage assignment using DNA microsatellite markers to evaluate performance differences between two populations of stocked walleye. American Fisheries Society National Meeting. Charlotte, NC. August 1999. (Variations of this talk were also given at the Minnesota Department of Natural Resources, New Ulm, MN, February 2000; and the Midwest Fish and Wildlife Conference, Chicago, IL, December 1999.

Fellowships & Awards

Faculty Merit Award. SAFS, UW 2007.

Population Dynamics Fellowship. National Marine Fisheries Service & National Sea Grant, 2005 – 2007.

Graduate School Fund for Excellence and Innovation Scholarship. SAFS, UW 2002 – 2003.

Keeler Memorial Scholarship. SAFS, UW 2001.

Pre-Doctoral Intramural Training Award. National Human Genome Research Institute, NIH 1996 –1997.

Student Research Training Award. National Cancer Institute, NIH 1994.


American Fisheries Society