The California Current Ecosystem (CCE), extending from British Columbia to Baja California, Mexico, is one of the most productive ocean ecosystems in the world. It’s also extremely variable, and subject to periods of upwelling that cause low oxygen conditions (hypoxia). Future climate change is projected to cause rapid declines in oxygen concentration, and there has already been a decline in oxygen concentrations in the ecosystem in recent years.
This project focused on assessing present and future species vulnerability to hypoxia in the California Current Ecosystem. The goal of this project was to apply a modeling framework, integrated with earth system models, to project species responses to temperature-dependent hypoxic habitat compression in the California Current Ecosystem. This project addresses priority topic areas related to fisheries, ecosystem, and management responses to changing climate. The project built upon a broader project recently funded by the National Oceanic and Atmospheric Administration (NOAA) to evaluate the vulnerability of the California Current Ecosystem to multiple stressors of temperature and oxygen loss driven by climate change.
The project resulted in multiple journal articles, including a 2022 paper in Global Change Biology that included. By 2100, the paper notes, changes to the CCE will impact biological processes in many species, with some metabolic rates increasing by as much as 25%. The changes will be most severe in the north, where the impacts of climate change are projected to be more pronounced. The shallow waters along the inner continental shelf will be heavily impacted too, since the species at these depths tend to be more sensitive to changes.
The authors identified two species for which they had combined temperature and oxygen sensitivities, northern anchovy and Alaska pink shrimp. Warmer temperatures will drive metabolic rates upwards for both species — and the decreasing oxygen levels will limit their energy. This means that the southern edges of both species’ current ranges, where water is warmer, will no longer be viable habitat; their ranges are expected to shift northward — which, given that these are both commercially harvested species, has key implications for fisheries and economies.