Climate-induced changes endanger future of coastal ecosystems

By Sara Adams

For the generations who grew up watching Finding Nemo, it might not come as a surprise that the West Coast has its own version of the underwater ocean highway – the California Current marine ecosystem (CCME). The CCME extends from the southernmost tip of California up through Washington. Seasonal upward currents of cold, nutrient-rich water are the backbone to a larger food web of krill, squid, fish, seabirds and marine mammals. The area is highly productive, supporting fisheries and livelihoods for tens of millions of West Coast residents.

However, climate change and subsequent changes in ocean pH, temperature and oxygen levels are altering the CCME — and not in a good way.

New research led by McGill University Biology Professor Jennifer Sunday and Professor Terrie Klinger from the Washington Ocean Acidification Center within EarthLab at the University of Washington warns that climate impacts will significantly affect twelve economically and culturally important species home to the CCME over the next 80 years. The northern part of this region and areas closer to shore will have the strongest responses to changing ocean conditions. The region can expect to see substantial loss in canopy-forming kelp, declining survival rates of red urchins, Dungeness crab and razor clams, as well as a loss of aerobic habitat for anchovy and pink shrimp.

Effects of changing climate are complex

Evaluating the biological effects of several environmental variables at once shows the complexities in climate sensitivity research. For example, while some anticipated environmental changes will boost metabolism and increase consumption and growth, accompanying changes in other variables, or even the same ones, could potentially decrease survival rates. Notably, physiological increases (such as in size, consumption or motility) are not always beneficial, especially when resources – such as food and oxygenated water – are limited.

Of all the climate effects modeled, ocean acidification was associated with the largest decreases in individual biological rates in some species, but the largest increases in others. This result emphasizes the need for continued research and monitoring to provide accurate, actionable information.

Consider this when enjoying your next clam linguine dinner or dropping a crab pot on a Saturday – species in the northern part of this region and those closer to shore will have stronger responses to changing ocean conditions.For the Pacific Northwest, this inner shelf is home to recreationally and commercially important species that support large coastal economies. In the Puget Sound alone, the commercial crab fishery reached an all-time high of $15.2 million in the 2020-21 season, according to the Washington Department of Fish and Wildlife.