Climate change threatens Chinook salmon throughout their life cycle

Abstract

Widespread declines in Atlantic and Pacific salmon (Salmo salar and Oncorhynchus spp.) have tracked recent climate changes, but managers still lack quantitative projections of the viability of any individual population in response to future climate change. To address this gap, we assembled a vast database of survival and other data for eight wild populations of threatened Chinook salmon (O. tshawytscha). For each population, we evaluated climate impacts at all life stages and modeled future trajectories forced by global climate model projections. Populations rapidly declined in response to increasing sea surface temperatures and other factors across diverse model assumptions and climate scenarios. Strong density dependence limited the number of salmon that survived early life stages, suggesting a potentially efficacious target for conservation effort. Other solutions require a better understanding of the factors that limit survival at sea. We conclude that dramatic increases in smolt survival are needed to overcome the negative impacts of climate change for this threatened species.

Role of carryover effects in conservation of wild Pacific salmon migrating regulated rivers

“…2010, Crozier et al. 2021). Additionally, it is important to consider the spatial resolution and shifting mosaic of water temperatures for processes related to thermoregulatory movements (Armstrong and Schindler 2013, Mejia et al.…”

“…Because river conditions may have carryover effects, however, mitigation strategies may be able to increase ocean survival by taking these effects into account. For example, climate change is anticipated to impact salmon populations through rising ocean temperatures (Crozier et al 2021). Even though freshwater carryover effects are generally not as strong as direct ocean effects, the cumulative effects of multiple freshwater covariates on ocean survival could be biologically significant.…”

“…For example, climate change is anticipated to impact salmon populations through rising ocean temperatures (Crozier et al. 2021). Even though freshwater carryover effects are generally not as strong as direct ocean effects, the cumulative effects of multiple freshwater covariates on ocean survival could be biologically significant.…”

“…2019, Crozier et al. 2021). However, we wanted to examine multiple life stages within an integrated model to standardize the magnitudes of association of covariates with survival.…”

Environmental Problem Analysis and Policy Recommendations on Pacific Northwest Salmon

“…For thousands of years, salmon shaped the lives of the people who have lived here since time immemorial. Moreover, Crozier et al [17] warned that salmon would become extinct by 2060 and this issue desperately needed immediate actions. There was a market failure at play, due to the tragedy of the commons.…”