Climate change and cetaceans: documented impacts

Cetaceans are among the first visible witnesses of climate disruption in the ocean. Shifts in grey whale migration, mass mortalities in the North Pacific (the 2019 UME), the gradual desertion of the Bay of Biscay by harbour porpoises, the growing scarcity of the copepod Calanus finmarchicus for right whales in the North Atlantic: all of these are signals documented by the scientific community. This database presents 15 major events since 2010.

First witnesses of the disruption

Shifts in grey whale migration, mass mortalities in the North Pacific (the 2019 UME), the desertion of the Bay of Biscay by harbour porpoises, the growing scarcity of Calanus for right whales: cetaceans are among the first visible witnesses of the effects of climate change on the ocean.

Also worth consulting

To understand how resilient species are to these pressures, see the IUCN database, the demography of cetaceans and the documented migration routes.

Thermal upheaval: how the ocean is changing for cetaceans

Ocean warming and acidification are redrawing cetacean habitats. Antarctic krill is retreating with the sea ice, weakening the position of fin whales and blue whales. In the North-East Pacific, the amphipods on which the grey whale feeds are declining, which contributed to the Unusual Mortality Event (UME) declared by NOAA in 2019: more than 600 grey whales dead in four years.

In the Arctic, the loss of ice opens new routes for killer whales, which are colonising waters once out of reach and putting increased pressure on narwhals and belugas. Temperate species are moving north: the common bottlenose dolphin in the English Channel, the fin whale in the North Sea. Conversely, tropical species are extending their range towards the poles, creating new interspecific interactions that are still poorly measured.