Ship Anchors Crush 15,000-Year-Old Antarctic Sea Life

New underwater footage reveals that ships visiting Antarctica are accidentally destroying some of the planet’s oldest marine creatures, including ancient sponges that may have lived for 15,000 years.

The first-ever video documentation of anchor damage in Antarctic waters shows cruise ships, research vessels, and fishing boats leaving behind scarred seafloors where vibrant ecosystems once thrived. Scientists captured dramatic footage of crushed sponge colonies and barren ocean floors where ship anchors and chains scraped across the seabed, creating lasting scars in one of Earth’s most pristine marine environments.

The study, published in Frontiers in Conservation Science, documents what researchers call a critically understudied conservation crisis. With over 70,000 tourists visiting Antarctica in the 2022-23 season alone, the pressure on these fragile ecosystems continues to mount.

Ancient Life Under Attack

At Yankee Harbour in the Antarctic Peninsula, researchers used underwater cameras to document the aftermath of ship anchoring. The footage shows a stark contrast between damaged and untouched areas of the seafloor—zones where anchors had dragged across the bottom were virtually lifeless, while adjacent areas teemed with marine creatures.

“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,” said Matthew Mulrennan, lead author and marine scientist who founded KOLOSSAL, an ocean exploration nonprofit.

These massive sponges, known scientifically as Anoxycalyx joubini, can reach heights of one to two meters and represent some of the most ancient life forms on Earth. The researchers found evidence of anchor chains creating deep grooves in the seafloor and discovered crushed colonies of cactus sponges that had been physically destroyed by anchoring activities.

What makes this damage particularly concerning is the incredibly slow pace of life in Antarctic waters. Unlike tropical marine environments where organisms grow relatively quickly, Antarctic species are adapted to extreme cold and have evolved to grow at glacial speeds.

Key Findings from Antarctic Waters:

• First documented video evidence of anchor damage in Antarctica
• Ancient sponges up to 15,000 years old threatened by ship anchoring
• Complete absence of marine life in areas where anchors had scraped
• At least 195 vessels recorded in anchorable depths during 2022-23 season

The Invisible Ecosystem Under Threat

The research revealed the extraordinary biodiversity that exists at anchorable depths around Antarctica. Beyond the ancient volcano sponges, the team documented Antarctic sun stars, giant Antarctic octopus, sea spiders, and a variety of fish species—all living in areas where ships routinely drop anchor.

“The weird and wonderful animals that are impacted, like sponges, are important for filtering water, carbon sequestration, and providing shelter, food, and complex habitats which benefit the whole marine ecosystem, including penguins and seals – the animals tourists come to see,” Mulrennan pointed out.

The irony is stark: tourists travel thousands of miles to see Antarctica’s wildlife, but the very ships bringing them there may be destroying the underwater ecosystems that support the charismatic animals they hope to observe.

Tracking the Damage

Using ship tracking data, the researchers documented extensive vessel activity at Yankee Harbour during just one month in 2023. Eight passenger vessels were recorded anchoring in the area, with ships ranging from 73 to 164 meters in length. Each anchoring event typically involves deploying 150 to 200 meters of heavy chain across the seafloor.

A crucial detail not emphasized in initial coverage reveals the scope of potential damage: if March 2023 anchoring levels are representative of the full tourism season, Yankee Harbour alone could experience 40 anchoring events each season. This means the same sensitive areas face repeated disturbance throughout the Antarctic summer.

The researchers noted that many ships now have dynamic positioning systems that could eliminate the need for anchoring, but these alternatives aren’t consistently used in Antarctic operations.

Slow Recovery in a Frozen World

The Antarctic marine environment presents unique challenges for ecosystem recovery. “Ecological recovery is really site specific. Things in cold waters are much slower growing than in warmer temperatures so I expect that recovery would take longer the higher the latitude,” explained co-author Dr. Sally Watson, a marine geophysicist from New Zealand’s National Institute of Water and Atmospheric Research.

The study references other Antarctic research showing that seafloor habitats haven’t recovered from mechanical disruption after 77 years and likely won’t recover for at least 100 years. This puts anchor damage in stark perspective—a single anchoring event could eliminate ecosystem functions for longer than a human lifetime.

Many Antarctic species are not only slow-growing but also endemic, meaning they exist nowhere else on Earth. These organisms have evolved over millions of years to thrive in one of the planet’s most extreme environments, making them irreplaceable components of global biodiversity.

An Unregulated Problem

“This is the first time the impacts of ship anchoring and chain damage are documented in Antarctic waters. Activities in Antarctica have a lot of strict rules around conservation, yet ship anchoring is almost completely unregulated,” Mulrennan noted.

This regulatory gap is particularly striking given Antarctica’s protected status under international treaties. While activities on land face strict environmental controls, what happens beneath the waves has received little attention from conservation authorities.

“Anchoring impacts are understudied and underestimated globally. It’s so important to recognize and mitigate the impacts across all industries and limit planned anchoring,” added Watson.

Solutions on the Horizon

The researchers propose several practical solutions to protect Antarctic marine life. These include establishing permanent moorings at frequently visited sites, creating designated “parking areas” where anchoring is permitted, and encouraging ships to use dynamic positioning systems instead of anchors.

Perhaps most importantly, the team recommends identifying vulnerable marine environments where anchoring would be prohibited entirely. Given the discovery of 15,000-year-old sponges and other irreplaceable species, some areas clearly deserve complete protection from any human disturbance.

The study also calls for better monitoring and documentation of anchoring activities. Currently, there’s no comprehensive database tracking where and how often ships anchor in Antarctic waters, making it impossible to assess the full scope of the problem.

A Global Wake-Up Call

“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,” Mulrennan concluded. “It’s a pressing environmental issue, but it’s out of sight, out of mind.”

As climate change reduces sea ice coverage around Antarctica, ships will gain access to previously protected shallow areas, potentially expanding the zone of anchor impact. The researchers warn that what they’ve documented at Yankee Harbour may be just the beginning of a much larger conservation challenge.

For an ecosystem that has remained largely pristine for millions of years, the question isn’t whether humans should have access to Antarctica—but whether we can visit responsibly enough to preserve what makes these waters so extraordinary in the first place.