September 11, 2024 — Human harvesting of krill in the Southern Ocean could threaten the recovery of whale species that were nearly wiped out by industrial whaling in the 20th century, according to a Sept. 10 study in Nature Communications.
The tiny, shrimp-like crustaceans known as krill are the essential food source for baleen whales such as blues and humpbacks. To feed, these giant marine mammals take in great gulps of ocean water, filtering krill through bristly mouth structures. Booming demand for krill as fish meal and omega-3 fatty acid nutritional supplements, however, could leave whales without enough victuals to sustain even their diminished numbers.
“Our calculations suggest an alarming possibility that we might harvest krill to the point where we do real damage to recovering whale populations,” said lead study author Matthew Savoca, a research scientist in the lab of Jeremy Goldbogen, associate professor of oceans in the Stanford Doerr School of Sustainability.
The results highlight a need for scientists, regulators, and industry to carefully assess the impacts of krill harvesting in the Southern Ocean at current levels before expanding. “With this study, we want to draw
attention to how there likely isn’t enough krill to support fully recovered whale populations, and now on top of that, we’re harvesting krill and plan to harvest more krill in the near future,” said Goldbogen, the study’s senior author.