Western Fisheries Science News, November 2014 | Issue 2.11

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After a research career lasting more than 60 years and spanning two centuries, WFRC Senior Scientist Emeritus Dr. Tosh Yasutake has decided to retire for the second and (perhaps) final time.

Yasutake served as an Army medic in the famed 442nd Regimental Combat Team during World War II, earning a Bronze Star for bravery.¹  After the war ended, he attended college on the GI bill and in 1953, he began his research career as a histopathologist at the U.S. Fish and Wildlife Service (FWS) Western Fish Nutrition Laboratory at Cook, Washington (now WFRC’s Columbia River Research Laboratory). In 1960, he transferred to WFRC-Seattle (then, the FWS Western Fish Disease Laboratory) to start a fish pathology diagnostic laboratory. His research assignment was to describe the histopathology of fish diseases of interest to the laboratory, identify etiologic agents, and confirm the provisional diagnoses of hatchery biologists working to improve the health, quality, and survival of anadromous salmonids released from federal and state mitigation hatcheries. As part of this pioneering work, Yasutake was one of the first scientists to recognize hepatoma (liver cancer) in a population of hatchery-reared rainbow trout and helped trace the disease to an aflatoxin produced by the mold Aspergillus flavis growing on fish diet ingredients during storage.

Yasutake also did pioneering research on infectious hematopoietic necrosis (IHN) disease and was instrumental in recognizing that the viruses of Oregon sockeye disease and Chinook salmon virus disease were one entity.  Because the renal blood-forming tissues were the specific target, Yasutake and his co-workers proposed the name infectious hematopoietic necrosis in their 1969 seminal publication: Amend, D. F., Wm. T. Yasutake, and R. W. Mead. 1969. A hematopoietic virus disease of rainbow trout and sockeye salmon. Transactions of the American Fisheries Society 98:796-804.

In 1980, Yasutake was awarded a Ph.D. by the University of Tokyo, the first American to have been so honored. In 1983, he published “The Microscopic Anatomy of Salmonids: An Atlas” which quickly became a standard reference text in ichthyology/fishery biology. Due to continuing demand, it was reprinted by the FWS in 2004 and is still in wide use today. (Yasutake, W. T., and Wales, J. H. 1983. Microscopic Anatomy of Salmonids: An Atlas. U.S. FWS Resource Publication 150. Washington D.C.).

After receiving the American Fisheries Society S.F. Snieszko Award for making lasting contributions to his field, Yasutake retired from the Center (for the first time) in 1988. However, he soon returned as Senior Scientist Emeritus and continued coming to his office at the lab 2 days a week for the next 26 years ─ working on a variety of projects and answering requests for technical assistance in difficult to diagnose fish disease problems from federal and state conservation hatcheries, and from the aquaculture industry worldwide. His culminating project was to scan hundreds of his lifetime collection of photomicrographs of fish disease pathogens and selecting about 100 of those best illustrating parasite infections of economically important anadromous salmonids. He then prepared an electronic atlas of these photomicrographs “Histopathology of Selected Parasitic Salmonid Diseases: A Color Atlas” that is now posted on the WFRC website and linked to the American Fisheries Society Fish Health Section website. 

During his 60 year career, Yasutake saw the Center renamed 4 times (National Fisheries Research Center, Pacific NW Natural Science Center, National Biological Science Center, Western Fisheries Research Center) and transferred into or out of 4 government agencies (U.S. Fish and Wildlife Service, National Biological Survey, National Biological Service, U.S. Geological Survey). Despite the interruptions caused by all these reorganizations, Yasutake was still able to maintain a high level of productivity and he is widely recognized for his pioneering work in fish histopathology. Although his presence will be sorely missed, his research contributions have become part of the foundation of today’s knowledge of fisheries biology and have assured him a place in history.

¹In 2011, Yasutake’s army regiment was awarded a Congressional Gold Medal and the French Legion of Merit for its service.  In 2012, Yasutake received the Legion of Honor, France’s highest recognition for service to the country. 

Newsletter Authors - Debra Becker and Gary Wedemeyer

Research

USGS Visits China for Project with the World Organization for Animal Health:  WFRC Scientist, Jim Winton, returned from a week in Shenzhen, China visiting with staff of the Key State Laboratory of Aquatic Animal Diseases as part of an international project funded by the World Organization for Animal Health (OIE). The project involves the exchange of principal investigators and staff between the two laboratories with a goal to increase the number of OIE Reference Laboratories in the world, especially in countries with significant problems from diseases listed by the OIE. The WFRC is currently the sole OIE Reference Laboratory for infectious hematopoietic necrosis (IHN), a virus disease of salmonid fish that was originally endemic only to North America, but has emerged to become a significant problem affecting coldwater aquaculture in Asia. The goal of the project is to provide the training and experience to allow the Key State Laboratory of Aquatic Animal Diseases to be designated as a new OIE Reference Laboratory for IHN.

Fishery Biologist Appointed Co-Leader of Fish Migration Team for Mekong River Fish Biology Project: Research Scientist John Beeman was recently appointed as co-leader of a Fish Migration Team for the Mekong River Fish Biology Information Gap Assessment and Capacity Building in Laos project, a component of DOI-ITAP’s (International Technical Assistance Program) Smart Infrastructure for the Mekong program, funded by USAID. Beeman will work with David Hand (USFWS-Columbia River Fisheries Program Office, Vancouver, WA), fish ecology and fish genetics teams and ITAP personnel, and will travel to Laos PDR in the second quarter of 2015.

USGS Provides Fish Disease Diagnostic Training to Chilean Scientist:  During the week of October 27-31, a Chilean scientist, Pablo Lovera, visited the WFRC for advanced training in methods for detection of Renibacterium salmoninarum, the causative agent of bacterial kidney disease (BKD), which is one of the most prevalent diseases in salmonid aquaculture in Chile. Mr. Lovera is the laboratory manager for Etecma, an independent laboratory in Puerto Montt, Chile that provides fish disease diagnostic services for the salmonid aquaculture industry. The training was for specialized immunological  and molecular diagnostic methods that were developed by WFRC scientists and are recommended for BKD diagnosis by the OIE (World Organization for Animal Health) and the Fish Health Section of the American Fisheries Society. The WFRC is the OIE international reference laboratory for BKD, and has developed several of the recommended diagnostic methods for this disease as well as for certain other fish diseases.

Events

USGS Scientist Provides Science Cafe Lecture: On November 11, WFRC Research Ecologist, Jeff Duda provided a public lecture on the science supporting the Elwha River dam removal and restoration project. The Science Cafe of Olympia, like other science cafe events nationwide, encourages interaction and discussion between scientists and the public.

USGS Scientist Presents Research at Middle Columbia Wild Adult Steelhead Tributary Bypass Workshop: On November 19, WFRC Fish Biologist, Brady Allen, presented recent research about the extent that ESA listed mid-Columbia River steelhead populations travel the mainstem Columbia River during the winter prior to entering their spawning tributaries. This life history is not well documented and exposes the fish to additional risks while navigating the hydrosystem.

Publications

New Publication Describes Variation in Susceptibility of Steelhead Trout Populations to a Lethal IHN Virus: When a fish virus strain that was virulent for steelhead trout emerged in coastal Washington from 2007-2011 the distribution of virus detections and disease was not uniform along the coast. Researchers at the USGS Western Fisheries Research Center, supported by federal, tribal, and state fish health stakeholders, tested five different steelhead populations in experimental infection studies and found significant differences in susceptibility. Even within one watershed two steelhead populations differed significantly, and the more susceptible population had a much higher disease burden during the emergence. Thus one potential factor driving occurrence of disease on the landscape is variation in susceptibility to IHN virus. 

Breyta, R., A. Jones, and G. Kurath. 2014. Differential susceptibility in steelhead trout populations to an emergent MD strain of infectious hematopoietic necrosis virus. Dis. Aquat. Org. 112(1): 17-28. DOI: 10.3354/dao02781.