Author ORCID Identifier
Kaila J. Frazer: 0009-0005-7549-3529
Heather M. Welch: 0000-0002-5464-1140
L. David Smith: 0009-0001-4760-8078
Thomas A. Clay: 0000-0002-0644-6105
Steven J. Bograd: 0000-0003-3872-9932
Document Type
Article
Publication Date
1-21-2026
Publication Title
PLOS Climate
Abstract
Marine cold-spells are an understudied phenomena which can both negatively impact marine wildlife and provide thermal refugia for species displaced by climate change. To develop forward-looking and climate-ready management schemes, it is critical to examine how marine species respond to cold-spells, how long-term warming will affect marine cold-spells over the next century, and how these future cold-spells will in turn affect species of conservation concern, particularly in marine protected areas. To this end, we detect marine cold-spells across the California Current System, a productive Eastern Boundary Upwelling System, relative to a fixed baseline (1980–2009) and to a detrended time series that isolates cold-spells from long-term climate change. We then project the impact of future marine cold-spells on habitat suitability for two endangered top predators: leatherback turtles (Dermochelys coriacea) and blue whales (Balaenoptera musculus). Models project that 68–99% of the California Current System will no longer experience fixed baseline marine cold-spells by 2099 under a high emissions scenario, though marine cold-spells will still occur relative to a detrended time series. Blue whales lost 5% of their core habitat in National Marine Sanctuaries during historical marine cold-spells and are projected to gain 1–2% more core habitat during future, fixed baseline marine cold-spells. Leatherback sea turtles had little core habitat change during historical marine cold-spells but are projected to gain 4–5% more core habitat during future marine cold-spells. It is plausible that both species gain habitat during future marine cold-spells because these events provide thermal refugia to their prey. We urge conservationists and ecologists to increase their attention to marine cold-spells as potential thermal refugia and prioritize collecting data on endangered species’ prey in order to understand more deeply how species will respond to extreme temperature events.
Volume
5
Issue
1
Rights
This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
Version
Version of Record
Recommended Citation
Frazer, Kaila J.; Welch, Heather M.; Jacox, Michael G.; Lezama-Ochoa, Nerea; Abrahms, Briana; Pozo Buil, Mercedes; Benson, Scott R.; Palacios, Daniel M.; Smith, L. David; Clay, Thomas A.; Bograd, Steven J.; and Hazen, Elliott L., "Marine Cold-Spells in the California Current System: Modeling Changes in Frequency and Impacts on Endangered Species Habitat" (2026). Biological Sciences: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/bio_facpubs/344
Comments
All code used for analysis in this manuscript is available at https://github.com/kaila-frazer/MCS_in_the_CCS. Projected species distributions are available on ERDDAP (https://www.ncei.noaa.gov/erddap/index.html).