- Climate change: Warming ocean temperatures and changes in sea ice cover adversely affect krill populations, leading to shifts in their distribution and population declines.
- Ocean acidification: Increasing acidity levels in the ocean due to dissolved carbon dioxide can impair krill's ability to form their calcium carbonate shells, affecting their growth and survival.
- Overfishing: Krill is widely harvested for use as fishmeal, fish oil, and other products, leading to potential overexploitation of their populations, particularly in certain areas.
- Bycatch: Krill can be unintentionally caught as bycatch in fishing operations targeting other species, resulting in additional mortality.
- Pollution: Contaminants such as plastics, chemicals, and heavy metals entering the Antarctic ecosystem can affect krill directly and indirectly through the food chain, potentially impacting their health and reproduction.
- Habitat loss: Human activities like coastal development and tourism can alter or destroy krill habitats, such as the ice-edge environment, further impacting their populations.
Conservation measures, such as sustainable fishing practices, marine protected areas, and regulations on pollution, are essential for mitigating these threats and preserving Antarctic krill populations and the ecosystem they support.