Salmon Tipping Points: Data
Biometric analysis of historic Prince Williams Sound salmon populations over time. back to Salmon Tipping PointsOcean acidification has been identified as a stressor for aquatic species globally, including in the Northeast Pacific Ocean. Recent experimental work has shown negative effects of acidification on the growth and behavior of coho and pink salmon. Understanding the impacts of ocean acidification on the productivity of wild salmon populations, and how it interacts with other stressors such as climate change and increased competition due to hatchery supplementation, is critical for anticipating future population responses and for improving salmon management.
The Research Question
Is population productivity of pink salmon, measured as the number of recruits per spawner, affected by ocean acidification, climate warming, and competition with other salmon?
What We Did
What We Found
- Large-scale hatchery production negatively affects the productivity of wild pink salmon populations, likely via competition between wild and hatchery-reared juveniles in nearshore marine habitats.
- Data show effects of climate and species competition on salmon populations. For example, the 1988/89 regime shift in the North Pacific Ocean was associated with changing temperature-productivity and spawner-productivity relationships.
- Climate driven regime shifts affect the two broodlines differently, both in terms of recruitment and productivity
- Negative effects of ocean acidification are not yet detectable in wild PWS pink salmon, although this result was based on a relatively short time series (1980-2013) of model-derived ocean acidification proxies.
- Recruitment variation can be so large that it may obscure the effects of climate driven regime change
Why It Matters
Avenues for Future Work
Publications
Non-stationary and interactive effects of climate and competition on pink salmon productivity. https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.16049