Effects of warming climate and competition in the ocean for life-histories of Pacific salmon
Cline, T.J.; Ohlberger, J.; Schindler, D.E. (2019). Effects of warming climate and competition in the ocean for life-histories of Pacific salmon. Nature Ecology & Evolution 3(6): 935-942. https://dx.doi.org/10.1038/s41559-019-0901-7
In: Nature Ecology & Evolution. Springer Nature. ISSN 2397-334X, more
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| Authors | | Top |
- Cline, T.J.
- Ohlberger, J.
- Schindler, D.E.
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| Abstract |
The life-histories of exploited fish species, such as Pacific salmon, are vulnerable to a wide variety of anthropogenic stressors including climate change, selective exploitation and competition with hatchery releases for finite foraging resources. However, these stressors may generate unexpected changes in life-histories due to developmental linkages when species complete their migratory life cycle in different habitats. We used multivariate time-series models to quantify changes in the prevalence of different life-history strategies of sockeye salmon from Bristol Bay, Alaska, over the past half-century—specifically, how they partition their lives between freshwater habitats and the ocean. Climate warming has decreased the time spent by salmon in their natal freshwater habitat, as climate-enhanced growth opportunities have enabled earlier migration to the ocean. Migration from freshwater at a younger age, and increasing competition from wild and hatchery-released salmon, have tended to delay maturation toward the salmon spending an additional year feeding in the ocean. Models evaluating the effects of size-selective fishing on these patterns had only small support. These stressors combine to reduce the size-at-age of fish vulnerable to commercial fisheries and have increasingly favoured a single-age class, potentially affecting the age class complexity that stabilizes this highly reliable resource. |
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