Journal Article

Divergent responses of highly migratory species to climate change in the California Current

Lewison, Rebecca, Benson, Scott R., Muhling, Barbara, Dewar, Heidi, Bograd, Steven, Fiechter, Jerome, Becker, Elizabeth A., Lezama-Ochoa, Nerea, Cimino, Megan, Jacox, Michael G., Forney, Karin A., Farchadi, Nima, Hazen, Elliott L., Costa, Daniel, Welch, Heather, Buil, Mercedes Pozo, Brodie, Stephanie, Braun, Camrin

2024

Overview

Aim Marine biodiversity faces unprecedented threats from anthropogenic climate change. Ecosystem responses to climate change have exhibited substantial variability in the direction and magnitude of redistribution, posing challenges for developing effective climate‐adaptive marine management strategies. Location The California Current Ecosystem (CCE), USA. Methods We project suitable habitat for 10 highly migratory species in the California Current System using an ensemble of three high‐resolution (~10 km) downscaled ocean projections under the Representative Concentration Pathway 8.5 (RCP8.5). Spanning the period from 1980 to 2100, our analysis focuses on assessing the direction and distance of distributional shifts, as well as changes in core habitat area for each species. Results Our findings reveal a divergent response among species to climate impacts. Specifically, four species were projected to undergo significant poleward shifts exceeding 100 km, and gain habitat (~7%–60%) in response to climate change. Conversely, six species were projected to shift towards the coast, resulting in a loss of habitat ranging from 10% to 66% by the end of the century. These divergent responses could typically be characterized by the mode of thermoregulation (i.e. ectotherm vs. endotherm) and species' affiliations with cool and productive upwelled waters that are characteristic of the region. Furthermore, our study highlights an increase in niche overlap between protected species and those targeted by fisheries, which may lead to increased human interaction events under climate change. Main Conclusions By providing valuable species distribution projections, our research contributes to the understanding of climate change effects on marine biodiversity and offers critical insight and support for developing climate‐ready management of protected and fished species.

• Publisher: Wiley,John Wiley & Sons, Inc
• Subject: Anthropogenic factors / Biodiversity / California Current System / centre of gravity / climate / Climate change / coasts / Divergence / downscaled ocean projections / earth system model / ecosystems / ectothermy / endothermy / Environmental conditions / Fisheries / Geographical distribution / Habitat loss / habitat suitability index / Habitats / Human influences / humans / Marine ecosystems / Migratory species / Niche overlap / Ocean circulation / Pacific Ocean / Phenology / Protected species / RESEARCH ARTICLE / species distribution model / Thermoregulation / Variables / Whales & whaling