Whale recovery and the emerging human-wildlife conflict over Antarctic krill.

The Southern Ocean ecosystem has undergone extensive changes in the past two centuries driven by industrial sealing and whaling, climate change and commercial fishing. However, following the end of commercial whaling, some populations of whales in this region are recovering. Baleen whales are reliant on Antarctic krill, which is also the largest Southern Ocean fishery. Since 1993, krill catch has increased fourfold, buoyed by nutritional supplement and aquaculture industries. In this Perspective, we approximate baleen whale consumption of Antarctic krill before and after whaling to examine if the ecosystem can support both humans and whales as krill predators. Our back-of-the-envelope calculations suggest that current krill biomass cannot support both an expanding krill fishery and the recovery of whale populations to pre-whaling sizes, highlighting an emerging human-wildlife conflict. We then provide recommendations for enhancing sustainability in this region by reducing encounters with whales and bolstering the krill population. The Southern Ocean ecosystem is recovering from 20th-century industrial whaling, while the krill fishery in this region has grown rapidly and may expand further, driven by demand for supplements and aquaculture feed. This Perspective discusses how current krill biomass is unlikely to support both a growing krill fishery and rebounding whale populations in the Southern Ocean. [ABSTRACT FROM AUTHOR]