Bering Sea | Ecosystem Perspectives
Drivers and diversity of Chinook salmon productivity in the Arctic-Yukon-Kuskokwim region Presenter: Megan Feddern , meganlfeddern@gmail.com, University of Alaska Fairbanks Curry Cunningham , cjcunningham@alaska.edu Erik Schoen , eschoen@alaska.edu, UAF Rebecca Shaftel , rsshaftel@alaska.edu, Alaska Center for Conservation Science Recent declines in the abundance of many Chinook salmon ( Oncorhynchus tshawytscha ) populations have caused severe hardship in the Arctic-Yukon-Kuskokwim region. Given the rapidly changing ecosystems in this region, it is important to understand how conditions in freshwater and marine environments impact Chinook salmon throughout their life cycle and ultimately influence the productivity of these highly-valued stocks. It is particularly important to determine whether populations are responding synchronously or asynchronously to conditions, and whether Chinook salmon across watersheds and river basins are affected by the same drivers. To address this problem, we quantified the effects of environmental and ecological drivers (both freshwater and marine) on the productivity of 26 Chinook salmon population units in the AYK using a hierarchical Bayesian Ricker model. The population units tested represent four population units from the Yukon River basin in Alaska, eight population units from the Yukon River basin in Canada, and fourteen population units from the Kuskokwim River basin. We tested regional scale drivers that have been associated with Chinook salmon abundance and productivity in previous studies, including female body size, across shelf wind, and others. In addition, we developed time series for precipitation and streamflow using downscaled climate models (DAYMET, GloFAS) for individual watersheds. Some drivers (i.e. winter sea surface temperature, ice retreat) were associated with the productivity of Yukon population units but not Kuskokwim population units. Other drivers, such as abundance of North Pacific chum ( O. keta ) and pink salmon ( O. gorbuscha ), impacted the productivity of most population units similarly throughout the entire region. This work builds on previous research by offering a comprehensive analysis of environmental and ecological drivers across watersheds, spatial scales, and population units. Our results highlight the diversity in salmon-environment relationships across the AYK.
Alaska Marine Science Symposium 2023 60
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