Impacts of marine heatwaves on top predator distributions are variable but predictable

Marine heatwaves cause widespread environmental, biological, and socioeconomic impacts, placing them at the forefront of 21st-century management challenges. However, heatwaves vary in intensity and evolution, and a paucity of information on how this variability impacts marine species limits our ability to proactively manage for these extreme events. Here, we model the effects of four recent heatwaves (2014, 2015, 2019, 2020) in the Northeastern Pacific on the distributions of 14 top predator species of ecological, cultural, and commercial importance. Predicted responses were highly variable across species and heatwaves, ranging from near total loss of habitat to a two-fold increase. Heatwaves rapidly altered political bio-geographies, with up to 10% of predicted habitat across all species shifting jurisdictions during individual heatwaves. The variability in predicted responses across species and heatwaves portends the need for novel management solutions that can rapidly respond to extreme climate events. As proof-of-concept, we developed an operational dynamic ocean management tool that predicts predator distributions and responses to extreme conditions in near real-time.

Heather Welch, Matthew S. Savoca, Stephanie Brodie, Michael G. Jacox, Barbara A. Muhling, Thomas A. Clay, Megan A. Cimino, Scott R. Benson, Barbara A. Block, Melinda G. Conners, Daniel P. Costa, Fredrick D. Jordan, Andrew W. Leising, Chloe S. Mikles, Daniel M. Palacios, Scott A. Shaffer, Lesley H. Thorne, Jordan T. Watson, Rachel R. Holser, Lynn Dewitt, Steven J. Bograd, Elliott L. Hazen