Climate-driven global redistribution of an ocean giant predicts increased threat from shipping

Climate change is shifting animal distributions. However, the extent to which future global habitats of threatened marine megafauna will overlap existing human threats remains unresolved. Here we use global climate models and habitat suitability estimated from long-term satellite-tracking data of the world's largest fish, the whale shark, to show that redistributions of present-day habitats are projected to increase the species' co-occurrence with global shipping. Our model projects core habitat area losses of >50% within some national waters by 2100, with geographic shifts of over 1,000 km (~12 km yr⁻¹). Greater habitat suitability is predicted in current range-edge areas, increasing the co-occurrence of sharks with large ships. This future increase was ~15,000 times greater under high emissions compared with a sustainable development scenario. Results demonstrate that climate-induced global species redistributions that increase exposure to direct sources of mortality are possible, emphasizing the need for quantitative climate-threat predictions in conservation assessments of endangered marine megafauna.

Freya C. Womersley, Lara L. Sousa, Nicolas E. Humphries, Kátya Abrantes, Gonzalo Araujo, Steffen S. Bach, Adam Barnett, Michael L. Berumen, Sandra Bessudo Lion, Camrin D. Braun, Elizabeth Clingham, Jesse E. M. Cochran, Rafael de la Parra, Stella Diamant, Alistair D. M. Dove, Carlos M. Duarte, Christine L. Dudgeon, Mark V. Erdmann, Eduardo Espinoza, Luciana C. Ferreira, Richard Fitzpatrick, Jaime González Cano, Jonathan R. Green, Hector M. Guzman, Royale Hardenstine, Abdi Hasan, Fábio H. V. Hazin, Alex R. Hearn, Robert E. Hueter, Mohammed Y. Jaidah, Jessica Labaja, Felipe Ladino, Bruno C. L. Macena, Mark G. Meekan, John J. Morris Jr., Bradley M. Norman, Cesar R. Peñaherrera-Palma, Simon J. Pierce, Lina Maria Quintero, Dení Ramírez-Macías, Samantha D. Reynolds, David P. Robinson, Christoph A. Rohner, David R. L. Rowat, Ana M. M. Sequeira, Marcus Sheaves, Mahmood S. Shivji, Abraham B. Sianipar, Gregory B. Skomal, German Soler, Ismail Syakurachman, Simon R. Thorrold, Michele Thums, John P. Tyminski, D. Harry Webb, Bradley M. Wetherbee, Nuno Queiroz, David W. Sims