18 January 2023: New paper “Strong and lasting impacts of past global warming on baleen whales and their prey”

Graph taken from cabrera et al. (2022)

The paper “Strong and lasting impacts of past global warming on baleen whales and their prey” by Andrea Cabrera, and co-authored by Scientific Committee members Christian Lydersen, Mads Peter Heide-Jørgensen, Nils Øien and Gísli A. Víkingsson, who sadly passed away last year, was recently published in Global Change Biology.

It investigates the responses to the rapid warming after the last glacial maximum (LGM) during the Pleistocene–Holocene transition (7–12 thousand years ago) of eight baleen whales and seven prey species across the Southern and the North Atlantic Ocean.

The authors analysed 7032 mitochondrial DNA sequences as well as genome-wide DNA sequence variation in 100 individuals. The changes in genetic diversity suggest that most baleen whale populations expanded after the LGM in both ocean basins due to changes in their prey and climate. Exponential increases in abundance in both baleen whales and their prey in the Southern Ocean were indicative of an increase in ocean productivity. In the North Atlantic Ocean, however, the demographic fluctuations observed in baleen whales and their prey were subtle, varying across taxa and time. The ocean-wide expansions and increases in abundance that were initiated by the post-LGM global warming, continued for millennia after global temperatures stabilized, reflecting long-lasting impacts of global warming on marine fauna which may be an indicator for the possibility that the current global warming has already set processes in motion that will result in long-term and wide-ranging rearrangements in marine ecosystems that will continue for thousands of years after temperature stabilises.

You can read the study by Cabrera et al. (2022) here: https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.16085

Learn more about baleen whales here: www.nammco.no/whales-dolphins-and-porpoises/