North Pacific Anadromous Fish Commission

Technical Report 18

Table of Contents

Winter Condition and Trophic Status of Pacific Salmon in the Gulf of Alaska

Charles D. Waters, Todd Miller, Emily Fergusson, Dion Oxman, Beverly Agler, and Edward Farley Jr.

Abstract Excerpt:
The marine ecology of Pacific salmon (Oncorhynchus spp.) during winter has been rarely studied compared to other seasons, largely because harsh environmental conditions in the North Pacific Ocean make conducting winter research surveys difficult. As a result, we do not fully understand the winter fitness (e.g., energy density, lipid content, protein content) of different age classes for each species of salmon or how winter fitness may be affected by environmental conditions, such as the recent marine heatwaves (Cavole et al. 2016; Chen et al. 2021). We also do not know the extent to which intra- and inter-specific competition may exist, although winter is considered a period when competition among salmon may be highest due to low prey biomass (Nagasawa 2000). Competition may be further intensified by large-scale hatchery releases of pink and chum salmon (e.g., Ohlberger et al. 2022). To address these and other knowledge gaps, a comprehensive ecosystem survey—the International Gulf of Alaska Expedition—was conducted on the Russian research vessel Professor Kaganovskiy with 21 scientists from Canada, Korea, Japan, Russia, and the United States. The survey spanned 30 days in February–March 2019 and covered nearly 700,000 km2 in the Gulf of Alaska (details and protocols described in NPAFC Secretariat 2018).

*This is the first paragraph of an extended abstract. Download the full abstract below.



Waters, C.D., T. Miller, E. Fergusson, D. Oxman, B. Agler, and E. Farley Jr.  2022.  Winter condition and trophic status of Pacific salmon in the Gulf of Alaska.  N. Pac. Anadr. Fish Comm. Tech. Rep. 18: 106–111.