Western Fisheries Science News, February 2017 | Issue 5.2

Sources/Usage: Some content may have restrictions. View Media Details

William Toshio (Tosh) Yasutake passed away peacefully at home on December 12, 2016, at the age of 94. He is survived by Fumi, his wife of 66 years, as well as four children and six grandchildren. With his death, the fish health community has lost an outstanding scientist as well as a kind, unassuming, and wonderful human being.

Tosh was born on June 10, 1922, in Seattle, Washington, to Jack and Hide Yasutake. He was in his first year of studies at the University of Washington when Pearl Harbor was attacked by Imperial Japan on December 7, 1941. Following the attack, Tosh and his family (father, mother, sister, and two brothers) were among the 110,000–120,000 people of Japanese ancestry who were forced from their homes on the Pacific coast and incarcerated in internment camps in the interior. In June 1942, Tosh enlisted in the U.S. Army, serving as an unarmed combat medic in the famed 442nd Regimental Combat Team, the most decorated unit for its size and length of service in the history of American warfare. Wounded in October 1944 during the Vosges Mountains campaign near Bruyères, France, Tosh was evacuated and missed the ensuing battle to rescue the “Lost Battalion,” at which his replacement was killed. Tosh returned to action in Italy in February 1945 and served until the end of the war in Europe, earning both a Purple Heart and a Bronze Star for bravery. In October 2010, the Congressional Gold Medal was awarded to the 442nd Regimental Combat Team, and in 2012 the surviving members were made chevaliers of the French Légion d’Honneur for actions contributing to the liberation of France in World War II.

After the war, Tosh returned to the University of Washington on the GI Bill and received a B.S. degree in zoology in 1951. In 1953 he began his research career at the U.S. Fish and Wildlife Service’s Western Fish Nutrition Laboratory at Cook, Washington, where he conducted pioneering research on nutritional fish diseases with John Halver. Tosh was one of  the first to recognize hepatomas in hatchery-reared Rainbow Trout and helped to trace the disease to an aflatoxin produced by the mold Aspergillus flavis, which grew during the storage of ingredients for fish diets. In 1960, he transferred to the Western Fisheries Research Center (WFRC) in Seattle (then called the Western Fish Disease Laboratory) to start a fish pathology diagnostic laboratory. There he described the histopathology of diseases of economically important fishes, identified etiologic agents, and worked with hatchery biologists to improve the health, quality, and survival of salmonids released from federal and state hatcheries. Tosh was instrumental in recognizing that the viruses of Oregon sockeye disease and Chinook Salmon virus disease were one entity and in giving the disease its present name: infectious hematopoietic necrosis. In recognition of his pioneering research, Tosh was awarded a doctorate in fish pathology by the University of Tokyo in 1980, the first American to have been so honored. In 1983, he published his classic textbook The Microscopic Anatomy of Salmonids: An Atlas, which quickly became a standard reference work in fish pathology and is still in wide use today. For his outstanding career achievements, in 1987 Tosh received the S. F. Snieszko Distinguished Service Award, the highest honor bestowed by the American Fisheries Society’s Fish Health Section (AFS–FHS). Tosh retired in 1988 but continued his research at the WFRC as a senior scientist emeritus, providing technical assistance to federal and state agencies and to the aquaculture industry worldwide. His culminating project was to digitize his lifetime collection of photomicrographs and prepare an atlas, “Histopathology of Selected Parasitic Salmonid Diseases: A Color Atlas,” that is now posted on the Web sites of the WFRC and the AFS–FHS. 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.

Newsletter authors Dr. Diane Elliott and Dr. James Winton

Publications

New Publication Assesses Early Detection Monitoring for Invasive Mussels: The ecological and economic costs of an invasive quagga or zebra mussel infestation in the Pacific Northwest of the U.S. would be significant. The development of invasive mussel monitoring programs in the Pacific Northwest provides a unique opportunity to evaluate a regional invasive species detection effort early in its development. Although efforts are underway to monitor for the presence of invasive mussels, assessments of whether these efforts provide for early detection are lacking. A recent article in Environmental Monitoring and and Assessment, scientists from USGS and Washington State University (WSU) find that while detection efforts have increased dramatically over the past few years the existing programs may not be sufficient to detect these invasive mussels early enough to prevent them from being spread to other areas. USGS and WSU are working together with, private, state (Idaho, Montana, Oregon, and Washington), tribal entities conducting early detection monitoring for quagga and zebra mussels to provide regional context and evaluate the development of early detection monitoring programs.

Counihan, T.D., and S.M. Bollens. Early detection monitoring for larval dreissenid mussels: how much plankton sampling is enough? Environ. Monit. Assess. 189: 98.

New Publication Evaluates Competition for Food by Juvenile Salmon and Nonindigenous Shad in the Columbia River Basin: In the lower Columbia River, juvenile Chinook salmon overlap with nonindigenous juvenile American Shad during July and August. American Shad juveniles are abundant and have the potential to reduce growth of young salmon through competition for food such as Daphnia. Daphnia—small planktonic crustaceans— are also important prey for salmon in the lower Columbia River, but it is unknown whether salmon diet overlaps with shad, and if so, whether diet overlap results in reduced fitness (for example, reduced growth) of salmon. In a recent article in Transactions of the American Fisheries Society, scientists from USGS Western Fisheries Research Center and Washington State University studied the diet and consumption of subyearling Chinook salmon and juvenile American Shad during periods of anticipated species overlap. While previous results show that shad reduce zooplankton availability for salmon, results here indicate that they also become important prey after Daphnia abundance declines. This change from planktivory to piscivory affords juvenile salmon greater growth opportunity in reservoir food webs.

Haskell, C.A., D.A. Beauchamp, and S.M. Bollens. 2017. Trophic interactions and consumption rates of subyearling Chinook Salmon and nonnative juvenile American Shad in Columbia River reservoirs. Trans. Am. Fish. Soc. 146(2): 291-298.