Research:

Fisheries

Current projects (2008-2010)

• Predicting the Effects of Ceratomyxa shasta on Klamath River Fall Chinook Salmon: Understanding the Balance Between Host Resistance and Parasite Pathogenesis
• Interannual and Geographic Trends in Catches of Albacore along the West Coast of North America
• Catch and Release Survival in the Live Fish Fishery: Can Release of Pregnant Females Be a Conservation Tool?

Predicting the Effects of Ceratomyxa shasta on Klamath River Fall Chinook Salmon: Understanding the Balance Between Host Resistance and Parasite Pathogenesis (R/RCF-24)

Jerri Bartholomew
Department of Microbiology
Oregon State University
220 Nash Hall
Corvallis, OR 97331
Phone: 541-737-1856
Fax: 541-737-0496
E-mail: bartholj@science.oregonstate.edu

Salmon losses in the Klamath River basin have had devastating impacts on coastal economies and tribal communities along the river. The effects of declining salmon runs throughout the region have been felt for several decades, but the reduction of the commercial catch by 90 percent in 2006 was a direct result of the weak returns of Chinook salmon to the Klamath River. Losses to coastal communities and the salmon troll industry were estimated to be $28 million in 2006 alone.

Infection by microbial parasites such as Ceratomyxa shasta has, in large part, been responsible for the declining numbers of juvenile Klamath River fall Chinook salmon. In 2004, approximately 45 percent of juvenile Klamath River salmon migrating toward the ocean were reported to have severe C. shasta infections. Yet we have only a limited understanding of how C. shasta infects fish, the conditions under which severe disease develops, and how the parasite lifecycle is perpetuated.

Dr. Bartholomew's laboratory has played a major role in addressing myxozoan disease problems in the Klamath River basin. Her team will work to understand how the parasite causes infection and disease in Chinook salmon.

Research outcomes: Mixozoan parasites in Klamath River salmon

Interannual and Geographic Trends in Catches of Albacore along the West Coast of North America (R/RCF-25)

William Pearcy
College of Oceanic and Atmospheric Sciences
Oregon State University
104 COAS Administration Bldg.
Corvallis, OR 97331
Phone: 541-737-2601
Fax: 541-737-2064
E-mail: wgpearcy@coas.oregonstate.edu

Albacore tuna along the west coast of the United States is a very valuable and productive fishery that is still open access. Little is known about how large-scale ocean events affect tuna catch rates, north/south distributions, and seasonality. To study such variations in the fishery, Dr. Pearcy's team will utilize an exceptionally long and accurate time series of data-1961-2006, from the Southwest Fisheries Science Center-that has not yet been analyzed. This research will provide information to managers and fishers on how large-scale ocean events affect catches. It will examine possible differences between southern and northern portions of the west coast fishery, based on catch distributions and how they are linked to catches farther offshore. Regional variations in the north/south distribution, and the month of the commencement and termination of the fishery, will be correlated with major changes in ocean climate, such as sea-surface temperature.

Catch and Release Survival in the Live Fish Fishery: Can Release of Pregnant Females Be a Conservation Tool? (R/RCF-26)

Scott and Selina Heppell
Fisheries & Wildlife
Oregon State University
104 Nash Hall
Corvallis, OR 97331
Phone: 541-737-9039
Fax: 541-737-3590
E-mail: selina.heppell@oregonstate.edu
Project Web site: www.oceanresourceteam.org/tagging

The live fish fishery in southern Oregon has increased dramatically in recent years, but the ecology and long-term sustainability of our near-shore fish stocks has not been well studied. Live fishing for near-shore rockfishes ("sea bass"), kelp greenling ("sea trout"), cabezon, and other species uses hook-and-line gear to capture fish alive for transport to high-end restaurant markets. Live fishing is a "clean" fishery with little bycatch and high price per pound. As a precautionary measure to contribute to annual replenishment of stocks, fishers in the Port Orford area have proposed to release female rockfish that are obviously carrying offspring (rockfish give birth to live young, rather than laying eggs). Similar measures have contributed to productivity and conservation in lobster fisheries in New England and crab fisheries on the west coast, and this would seem to be an obvious, and simple, conservation method. However, rockfish that are caught and brought to the surface may suffer gas bladder expansion and other potentially fatal injuries, which would make their release ineffectual. This project proposes to investigate the potential survival of released female rockfish and estimate the contribution that they could make to near-shore populations.

Dr. Heppell will collaborate with fishers and the Port Orford Ocean Resources Team and Port Liaison Project throughout the research project to assess and design a study, and offer training workshops for fishers participating in the project.

Former Sea Grant researchers: What they're doing now

• Gil Sylvia (Fisheries economics, value-added products)
• Michael Banks (Copper rockfish genetics and distribution)
• Alan Shanks (Fish dispersal and range)

Next topic: Ecosystems & habitats