06 November 2024: New study on climate variability and behavioural shifts in North Atlantic fin whales

A new study by Ruiz-Sagalés and colleagues, titled “Baleen stable isotopes reveal climate-driven behavioural shifts in North Atlantic fin whales”, was published in Science of the Total Environment last month. The researchers analysed the chemistry of baleen plates (i.e., the structures baleen whales have in their mouth to filter out seawater) using stable isotopes (i.e., forms of elements that don’t break down, acting like natural “fingerprints”) from 29 fin whales sampled off southwestern Iceland in summer to understand how climate variability affects their diet and migration.

The study found that stable isotope values of nitrogen and carbon in the baleen plates are linked to key climate patterns, such as the North Atlantic Oscillation (NAO) and the Atlantic Multidecadal Oscillation (AMO). During periods of high AMO and low NAO, krill abundance decreases due to climate conditions, so the whales switch to  prey that is higher in the food chain. The analysis also showed that during high AMO periods, fin whales migrate to higher latitudes, likely in response to warmer temperatures. These findings highlight the whales’ behavioural flexibility, which may help them cope with rapid climate change.

You can read the full article by Ruiz-Sagalés et al. here: https://doi.org/10.1016/j.scitotenv.2024.177164

Photo credit: GREMM