Antarctic krill are the foundation of one of Earth's most productive marine ecosystems, and their decline from fishing and climate change threatens millions of individual animals.
The welfare implications of krill ecosystem decline manifest in millions of individual animals simultaneously. Penguins that cannot find sufficient krill near colonies must travel further, burning energy reserves and leaving chicks hungry for longer. Breeding failure from nutritional stress means chicks starve. Humpback whales entering krill feeding grounds find reduced prey density, requiring more foraging effort for adequate energy intake. The cascade from krill to individual welfare of dependent species represents one of the clearest examples of how ecosystem-level changes translate to individual animal suffering at scale. Protecting krill populations serves as a leverage point for welfare improvement affecting the entire Antarctic food web.