Protect the Antarctic Peninsula BEFORE IT’S TOO LATE

ABanning fishing in warming coastal waters and limiting tourism and construction on land will help to protect marine mammals and seabirds.

mong the windswept glaciers and icebergs of the western Antarctic Peninsula is an oasis of life. Threatened humpback and minke whales patrol the waters. Fish, squid and seals swim alongside noisy colonies of chinstrap, Adélie and gentoo penguins on the shore. It’s a complex web of life. All these species feed on small, shrimplike crustaceans called Antarctic krill. And many are themselves prey for leopard seals, killer whales and predatory seabirds such as skuas and giant petrels.

This delicate and iconic ecosystem is in peril. The western Antarctic Peninsula (the northernmost part of the continent) is one of the fastest-warming places on Earth. In February, temperatures there reached a record 20.75 °C, with an average daily temperature that was 2 °C higher than the means for the preceding 70 years1. Most of the region’s glaciers are receding. And sea ice is dwindling — spring 2016 saw it retreat to the smallest extent since satellite records began in the 1970s. If carbon emissions keep climbing, in 50 years’ time, the area covered by sea ice will have halved and the volume of ice shelves will have shrunk by onequarter2.

Heavy fishing is depleting parts of the region of the main food source, krill. The waters around the peninsula are home to 70% of the world’s Antarctic krill, the larvae of which shelter in the sea ice3. Their loss means hunger for many species. It even alters biogeochemical systems in the ocean, including the carbon cycle3. Krill feed on phytoplankton — microscopic marine algae that extract carbon from the atmosphere. The krill excrete pellets containing carbon and other nutrients, including fluoride, calcium and phosphorus, which are energy sources for a myriad of microorganisms3.

The that factors threaten the Antarctic Peninsula’s ecosystems.

Fishing.

Krill fisheries in the Southern Ocean have been growing for decades, to meet rising demand for omega-3 dietary supplements and fishmeal. Almost 400,000 tonnes of Antarctic krill were caught in 2019 — the third-largest krill catch in history, a volume not seen since the 1980s. More than 90% was caught around the Antarctic Peninsula. The catch there has tripled since 2000, from 88,800 to 289,500 tonnes in 2018.

Tourism. The peninsula is the most-visited region in Antarctica (see ‘Voyage to the peninsula’). It’s close to South America and has dramatic scenery and an abundance of wildlife. Tourist numbers have doubled in the past decade — more than 74,000 people visited last year. Some popular sites receive around 20,000 visitors per season.

Research infrastructure.

Visiting scientists can also damage Antarctica’s environment. The peninsula has the highest concentration of research stations on the continent — 18 nations have science facilities there, covering fields from space physics to geoscience, wildlife monitoring and climate research. The researchers are attracted for the same reasons that the region is so biodiverse — accessible floes of sea ice shift through the seasons, and much of the land is icefree.

Climate change. Global warming threatens to unravel the ecosystem of the entire Southern Ocean. Its impacts are especially insidious off the Antarctic Peninsula, where species such as penguins, seals, whales and krill are struggling to cope with the loss of sea ice