Tourism surge puts Antarctica’s seafloor ecosystems at risk

More people than ever are setting sail for Antarctica, but while tourism enables people to marvel at ice landscapes, penguins and seals above the surface, new research reveals a disturbing truth beneath the water.

For the first time, scientists have captured underwater footage of anchor and chain damage on the Antarctic seafloor—revealing a hidden threat to one of the most remote and fragile ecosystems on the planet.

“This is the first time the impacts of ship anchoring and chain damage are documented in Antarctic waters,” says author Matthew Mulrennan, a marine scientist from the University of California, San Diego. “Activities in Antarctica have a lot of strict rules around conservation, yet ship anchoring is almost completely unregulated”.

The team’s findings, published in Frontiers in Conservation Science, reveal scarring from anchors and chains across sites in the Antarctic Peninsula and South Georgia Island.

Using underwater cameras deployed at 36 locations during the 2022–23 summer, the researchers documented striations, grooves, and muddy seafloor disturbance in areas where ships had anchored.

In these scarred zones, sponge colonies lay crushed, and marine life had all but vanished. Just meters away, the untouched seabed teemed with biodiversity.

“The observed damage was a near miss to three giant volcano sponges, believed to be the oldest animals on the planet, which may live up to 15,000 years,” says Mulrennan.  “Many other species, including Antarctic sun stars, giant Antarctic octopus, sea spiders, and a variety of fish were recorded at anchorable depths”.

Many of these animals are also becoming sessile and endemic to the region.

“Documentation is way overdue, given the importance of these ecosystems and the protections we place on them,” says co-author Dr Sally Watson, a marine geophysicist at the National Institute of Water and Atmospheric Research in New Zealand.

The researchers are calling for more work to assess the long-term effects of anchoring and how ecosystems respond over time.

“Anchoring is likely the most overlooked ocean conservation issue in terms of global seafloor disruption; it is on par with the damages from bottom trawling,” says Mulrennan. “It’s a pressing environmental issue, but it’s out of sight, out of mind.”

Over the past few decades, the number of tourists visiting Antarctica has grown rapidly, from about 8,000 in the mid-1990s to almost 125,000 in 2023-24.

The boom is set to continue, with annual visitor numbers forecast to reach 452,000 by 2033-34 – equating to an almost fourfold increase on current levels.

Last month, a separate study from Queensland University of Technology warned that the Antarctic tourism boom may be nearing a critical threshold. Published in the Journal for Sustainable Tourism, the researchers stated: “Antarctica may be in danger of joining other globally iconic destinations which have been reportedly loved to death.”

Tourism and the Antarctic

“Managing tourism in Antarctica is uniquely challenging due to the region’s remoteness, its fragile ecosystems and the complexity of its international governance,” says lead researcher Dr Valeria Senigaglia, from Queensland University of Technology (QUT) Antarctic research group Securing Antarctica’s Environmental Future.

Her team advocates a multi-layered approach: combining site-specific regulations with broader economic strategies such as visitor caps, targeted tourism fees, and stricter operator certification. “These could offer a more adaptive, effective approach,” Senigaglia says.

For more than sixty years, human activity in Antarctica has been governed by the Antarctic Treaty System—a legal framework built on the 1959 Antarctic Treaty. Its cornerstone conservation document, the 1991 Madrid Protocol, applies to all activities including tourism. But in practice, much of the system depends on voluntary industry compliance.

Although this study is the first to document anchoring damage in polar regions, the broader problem is hardly new, says Professor Andy Davis, a marine biologist at the University of Wollongong, who was not involved with the research paper.

“Images of coral reef destruction associated with the anchoring of cruise ships in the Caribbean date from the mid 1970’s,” he told Cosmos. “More recently, as cruise vessels sought safe harbour at the height of the Covid pandemic, tropical reefs on the small Caribbean nation of Barbados were decimated.”

Davis says the boom in cruise tourism has only made the problem worse.

“In the three decades prior to Covid the number of cruise ship passengers jumped almost 10-fold to nearly 30 million per annum. When this is combined with an emphasis on taking passengers to experience unspoilt locations off the ‘beaten track’ – such as Antarctica – the scale of the issue is brought into sharp focus.”

The research identifies a key knowledge gap – the rate at which life on the sea floor will recover from anchor damage. “In the cold polar regions, recovery would be expected to be glacial – pun intended,” Davis says.

Not all cruise companies use anchors.

“Charting a course to a greener and more sustainable shipping industry requires the industry to acknowledge that their routine anchoring practices are destructive and avoid anchoring on or near sensitive marine habitats,” Davis says.

“The safest option is not to anchor at all – dynamic positioning allows vessels to ‘hold station’, for example. Currently, anchoring is not regulated by the shipping industry, but this must change if the integrity of marine ecosystems is to be assured”.