Pathogens and Stressors of Overwintering Salmon in the Gulf of Alaska

Abstract Excerpt:
Pacific salmon (Oncorhynchus spp.) are a keystone species across the North Pacific, supporting ecosystems, commercial opportunities, and cultural identity (Cederholm et al. 1999; Lichatowich and Lichatowich 2001; Radchenko 2006). Nevertheless, many wild salmon stocks have experienced significant declines associated with declines in marine survival (Holtby et al. 1990; Nagasawa 2000; Radchenko 2012; Naydenko et al. 2016; Shuntov et al. 2019). Salmon restoration efforts focus mainly on fresh and coastal waters, but little is known about the open ocean environment. Specifically, the health and condition of salmon during the winter months in the Northeast Pacific are poorly characterized. To address these knowledge gaps, an end-of-winter survey in the Gulf of Alaska (GoA) in February and March of 2019 was initiated under the banner of the International Year of the Salmon (IYS) initiative onboard the Russian research trawler Prof. Kaganovskiy. Oceanographic sampling and trawl surveys were performed to provide the baseline data for future pan basin studies. We applied high throughput RT-qPCR tools to provide the first report on the health, condition, and infection profile of coho O. kisutch, chum O. keta, pink O. gorbuscha, and sockeye O. nerka salmon in the Gulf of Alaska (GoA) during the winter.