North Pacific Anadromous Fish Commission

Technical Report 23

Table of Contents

Where Have All the Chum Salmon Gone? An Assessment of Marine Critical Periods for Western Alaska Chum Salmon During Periods of Extreme Events in their Early Marine and Winter Ocean Habitats

Authors:
Edward V Farley, Jr., Lukas DeFilippo, Emily Fergusson, Todd Miller, James Murphy, Kathrine Howard, Sara Gilk-Baumer, Dion Oxman, and Laurie Weitkamp

Abstract Excerpt:
Record low run sizes of Chum salmon (Oncorhynchus keta) were observed in western Alaska from 2020 to 2022 following marine heat waves (extreme events) that occurred in their early marine and winter ocean habitats. Climate warming impacts on Arctic-Yukon-Kuskokwim (AYK) Chum salmon ecology in freshwater and marine habitats is a shared concern among Alaskan communities. The life history of AYK Chum salmon includes a short period within freshwater habitats, where adults spawn during fall months, eggs hatch during early spring the following year, and smolts leave freshwater and enter the marine environment during late spring and early summer (Urawa et al. 2018). During their first summer at sea, they are found feeding and growing within the shelf regions of the northern and southern Bering Sea as well as the Chukchi Sea. During late fall and winter, they migrate offshore where they overwinter in the Gulf of Alaska (GOA) and eastern North Pacific Ocean (NPO; Myers et al. 2007).  They continue their migratory pattern of wintering in the GOA and eastern NPO and summering in the Bering Sea and western GOA for one or more years before migrating back to their natal rivers during spring to begin the cycle again (Fig. 1).

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

DOI:
https://doi.org/10.23849/npafctr23/kccc-5p

Citation

Farley, Jr., E.V., L. DeFilippo, E. Fergusson, T. Miller, J. Murphy, K. Howard, S. Gilk-Baumer, D. Oxman, and L. Weitkamp.  2024.  Where have all the chum salmon gone? An assessment of marine critical periods for western Alaska chum salmon during periods of extreme events in their early marine and winter ocean habitats.  N. Pac. Anadr. Fish Comm. Tech. Rep. 23: 88–91.  https://doi.org/10.23849/npafctr23/kccc-5p