Mapping Baleen Whale Habitats in Antarctica

In the waters surrounding Antarctica, some of the largest animals on Earth are gathering in places that scientists say remain insufficiently protected.

Using whale observations collected during 14 years of Antarctic expeditions, researchers identified key feeding areas for fin, humpback, blue, and minke whales across the Southern Ocean. The study, based on surveys conducted between 2010 and 2024, traced whale distributions from the Drake Passage to the Weddell Sea and compared them with regions known for high concentrations of Antarctic krill, small crustaceans that form a central part of the Antarctic food web.

The results showed a clear geographic pattern. Humpback whales ranged widely through Antarctic waters, while fin whales were concentrated mainly north of the Antarctic Circle. Blue whales, still recovering from industrial whaling that devastated their populations during the twentieth century, were found farther south near the sea ice edge. Minke whales occupied the broadest range of all, extending deep into ice covered regions that few other whale species use regularly.

Several areas emerged as major hotspots where whale species repeatedly overlap. Among the most important were the Bransfield Strait, the Antarctic Sound, the Scotia Sea, and waters surrounding the South Orkney Islands. These same regions are also linked to favorable conditions for Antarctic krill, reinforcing the close relationship between whales and one of the Southern Ocean’s most important species.

Yet the study also found that existing protections cover surprisingly little of this habitat. The South Orkney Islands Southern Shelf Marine Protected Area, currently the only established protected area in the region, included less than 1 percent of recorded fin whale sightings and no blue whale sightings at all.

The picture changed substantially when researchers examined two proposed marine protected areas in the Antarctic Peninsula and Weddell Sea. Together, those areas overlapped with more than half of recorded humpback and minke whale sightings, as well as significant portions of fin and blue whale observations. According to the authors, the results suggest the proposed protected areas closely match the regions most important for baleen whales during the feeding season.

The findings arrive as Antarctica faces mounting environmental pressure. Climate change is altering sea ice patterns across the region, while krill fishing and growing ship traffic are increasing human activity in waters that support some of the planet’s richest marine ecosystems.

For researchers, the study offers rare long term evidence linking whale distributions to conservation planning. More broadly, it highlights how protecting Antarctica’s feeding grounds could shape the future recovery of species that once nearly disappeared from the Southern Ocean entirely.

Léa Zinsli, PolarJournal