Unlocking the Secrets of Killer Whale Diets and Their Role in Climate Change
Killer whale populations are invading the Arctic, creating major disruptions to an ecosystem already severely impacted by climate change. A team of researchers from McGill University has discovered new clues to understand how killer whales impact their environment – by reconstructing their diets using the lipids in their blubber.
“Using this analysis, we will better understand how their diets change and how they may potentially disrupt Arctic food webs,” said Anaïs Remili, a PhD candidate at McGill’s Department of Natural Resource Sciences and lead author on the study.
To reconstruct the whales’ diets, the researchers used a model called Quantitative Fatty Acid Signature Analysis (QFASA) using samples from captive killer whales. Then they measured the fatty acid composition of the wild Greenland killer whales and potential prey species the whales may feed on. Finally, they applied the modeling approach to estimate that the whales mainly feed on harp and hooded seals, species that researchers found in some of the whales’ stomachs.
This new tool has the potential to increase understanding of the diets of killer whales around the world, and how killer whales may impact Arctic food webs in the future.
Reference: “Validation of quantitative fatty acid signature analysis for estimating the diet composition of free-ranging killer whales” by Anaïs Remili, Rune Dietz, Christian Sonne, Sara J. Iverson, Denis Roy, Aqqalu Rosing-Asvid, Haley Land-Miller, Adam F. Pedersen and Melissa A. McKinney, 13 May 2022, Scientific Reports.