Antarctic krill are the keystone species of the Southern Ocean food web, and commercial harvesting for aquaculture feed and supplements creates competition with whales, penguins, and seals who depend on krill exclusively.
Individual krill welfare capacity is debated, but the aggregate effect of krill depletion on dependent predators is a significant welfare concern. Whales that cannot find sufficient krill face nutritional stress and may fail to reproduce. Penguin chick starvation occurs when adults cannot find prey near colonies. Seals that deplete krill near their pupping beaches face the same problem. The combination of climate-driven krill decline and commercial harvest creates cumulative pressure on the Southern Ocean food web. Choosing algae-based omega-3 supplements over krill oil provides human consumers with equivalent nutritional benefit while eliminating the competition with wild predators for this keystone resource.