The Antarctic krill fishery has reached its annual catch threshold for the second consecutive year, raising concerns over fishing pressure in key feeding grounds used by penguins, seals and whales. While the existing system ensures fishing stops when the threshold is reached, the shrinking fishing window and concentration of catches in fewer areas highlight the need for stronger spatial and seasonal management, according to a new report. “The system is working. The fishing stops when the trigger level is reached,” said Tina Schoolmeester, lead author of Finding Common Ground for Antarctic Krill Management and strategic lead (Innovation Project Development) at GRID-Arendal.
“There has been an increase in krill fishing in recent years but never over this trigger level. What has changed is that rather than being more evenly spread across the year, the time window has shrunk. Hence the trigger level being reached already in August both in 2025 and 2026. So the pressure is, in that sense, that more is caught in a shorter time frame and in fewer areas,” she said.
The report published in October by GRID-Arendal, the University of the Arctic and Zoï Environment Network, highlights the challenge of balancing commercial fishing with conservation of the Southern Ocean ecosystem. The fishery reached the 620,000-tonne trigger level on August 12 this year, forcing fishing to stop for the season. The same threshold was reached on August 1 in 2025. In both years, catches were concentrated north of the Antarctic Peninsula and around the South Orkney Islands.
Antarctic krill (Euphausia superba), a small crustacean roughly the size of a thumb, collectively account for the largest biomass of any wild animal on Earth. They are a critical food source for penguins, seals and whales and play an important role in ocean nutrient cycling and carbon sequestration. Around 30% of the total krill biomass is concentrated in the Scotia Sea and the region north of the Antarctic Peninsula, where many predators breed and feed and most fishing takes place. The management challenge has intensified since 2024, when the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), which regulates Southern Ocean fisheries, failed to agree on extending “conservation measure”. Introduced in 2009, the measure distributed catches across four subareas of ‘fishing Area 48’ to prevent excessive concentration in any one location.
Following its expiry at the end of the 2024 fishing season, the 620,000-tonne trigger level remained in place, but the earlier subarea allocations lapsed. The entire amount can now be caught across the four subareas, subject to existing restrictions on where fishing is permitted.
Area 48 also has a precautionary catch limit of 5.61 million tonne per fishing season. The much lower trigger level activates additional management measures and remains the operative seasonal threshold. The fishery operates on an “Olympic” basis, with vessels competing to catch krill until the threshold is reached. According to the report, catches have returned to levels last seen in 1987, although vessels are now larger. Two large-scale surveys conducted in 2000 and 2019 suggest that overall krill biomass has remained relatively stable. However, krill movement and replenishment remain poorly understood, and the cumulative effects of fishing and climate change are uncertain. Schoolmeester said penguins could be among the predators most directly exposed to concentrated fishing, particularly around the Antarctic Peninsula. During their breeding season, roughly November to March, penguins have limited mobility and depend on krill available relatively close to their colonies.
“The concentration of fishing in coastal areas can therefore increase the potential for competition between fisheries and krill-dependent predators, particularly during summer when penguins are breeding and their foraging range is constrained,” she said. Many operators have voluntary restricted fishing zones around penguin colonies during summer, but these generally cover only three to four months. Whether they provide sufficient protection remains uncertain, particularly as fishing can resume in these areas outside the breeding season. Antarctic fur seals are also a concern. Schoolmeester cited research indicating that pup counts at the two main breeding colonies around the South Shetland Islands declined by up to 90% between 2008 and 2023. Newly weaned pups from Cape Shirreff remain largely over the continental shelf and slope north of the pack ice, overlapping with current fishing grounds. Adult females may have to travel farther or spend longer foraging, potentially affecting pup growth and survival.
However, she cautioned that fishing alone cannot explain these declines. Sea-ice loss, ocean warming, entanglement and other environmental pressures may also contribute. Whale populations have recovered substantially since historical whaling, and sightings around the Antarctic Peninsula have increased over the past two decades. But this does not establish whether concentrated fishing affects whales’ access to krill.
Climate change could further alter the picture. Research cited by Schoolmeester indicates that ocean warming and changing sea-ice dynamics are contributing to a southward contraction of krill habitat in the Southwest Atlantic sector. Changes in krill abundance and swarming behaviour could affect predator-prey relationships and reduce the amount of carbon transported to the deep ocean.
Schoolmeester called for seasonal closures around penguin colonies, protection of juvenile fur seal habitats and spatial safeguards for important feeding grounds. She also stressed the need for more targeted krill surveys, consistent monitoring of predator populations and breeding success, and better data on fishing activity, bycatch and seal entanglements.