Never-before-seen images filmed in Antarctica show traces of anchoring on a deep, untouched seabed. Without concluding that there is a definite impact, a study invites us to consider the potential effects of human activities on these fragile ecosystems.
Ascidians, worms, sponges, starfish, giant volcanic sponges (the oldest animals on the planet), crinoids, fish… These animals can be seen thriving on an intact substrate, submerged under 70 meters of seawater, just a stone’s throw from an Antarctic island, in videos published in the journal Frontiers in Conservation Science on June 9.
Also visible are grooves formed in the mud by the mooring of a ship, and the debris of sessile animals – sponges, according to the authors. The study brings to the surface a central issue of the Antarctic Treaty: the impact of human activities on some of the least documented marine ecosystems. The authors hypothesize that tourism, research, fishing and recreational vessels could significantly damage the Antarctic seabed at depths exceeding 25 metres.
Looking at the images, it’s hard to deny an “impact”, but it’s just as hard to quantify. The study concedes that it is not possible to estimate the number of anchorages made each year, and that some vessels use dynamic positioning, i.e. an automatic system using propellers and bow thrusters to park without dropping anchor.
To make up for the lack of information, the study recalls the 2023 figures for tourist numbers in Antarctica: 70 operational tourism vessels and 70,000 people calling at the coast. To this, it adds the 52 research vessels, half as many pleasure craft, the Southern Ocean fishing fleet and illegal fishing.
An age-old fauna
Within the flexible framework of the word impact, many unresolved questions arise, such as the number of moorings, but also the regeneration of these ecosystems. Sessile fauna is, by definition, unable to move and is therefore more vulnerable. Among the diversity of organisms observed, some of these animals are long-lived, like the giant volcanic sponge, 1 to 2 metres long and probably several hundred years old, identified at the edge of the ploughing.
The authors estimate that ecosystem regeneration could take from 70 years to a century. “Recovery time and the extent of damage in Antarctica remain unknown, however – it’s a question we encourage further exploration of,” explains Matthew Mulrennan, lead author of the study and director of the NGO Kolossal, in an email exchange with polarjournal.net.
Could it be that the authors were trying to lend weight to their study by highlighting a worrying context? The images are unmistakable, but they remain confined to a small area, making it difficult to extrapolate to the rest of the continent, and the study makes no claim to the contrary. Which begs the question: did the media, who picked it up unfiltered, pointing the finger at the evils of cruising, actually read it?
Icebergs?
In response, comments on social networks point the finger at the action of icebergs. The chunks of ice that regularly break away from the glaciers wash up on the coast, scraping the substrate. So should the impact of the anchor and the hundred meters of chain be put into perspective?
On this side, the study bases its reasoning on other research, which has shown that the effect of icebergs “diminishes significantly beyond 25 meters”. “The seabed untouched by icebergs is virtually pristine, and home to some of the world’s largest and oldest sponges”, observes Matthew Mulrennan.
The impact of anchorages on the seabed is a worldwide concern. Is Antarctica the last territory to be spared, or is this just a new awareness on an international scale? The authors unearthed the issue while conducting exploratory work in Antarctica, aboard the cruise ship Ocean Endeavour, in Yankee Harbour, in March 2023.
“This was not a study directed specifically at damage caused by anchoring. It was observed opportunistically during other surveys,” replied Matthew Mulrennan before introducing his NGO. “Kolossal specializes in ocean exploration. We coordinated a quadripartite research partnership involving a camera technology company, a university, a tourism operator and scientists from NGOs.”
The team was unable to get any more shots, or any other scenarios, despite the dozen or so anchorages made by the ship during its loop around the Antarctic Peninsula. “If we’d had an ROV or other mobile device, we’d have been able to observe the impacts live”, laments the author. To publish these images, the director of Kolossal received financial support from some of the Ocean Endeavour‘s passengers.
“We are currently in the process of defining the next steps for our research into the extent and duration of the impacts of anchoring in Antarctica. Some tourism operators have expressed an interest in continuing to support our fieldwork,” explains Matthew Mulrennan.
Between everyone’s right to roam and live on the seas, and everyone’s duty to protect the seabed, it’s sometimes hard to decide. Perhaps we can’t always come to a conclusion. An anchor is an anchor (wasn’t it Joseph Conrad who wrote that “from beginning to end, a sailor’s thoughts are largely occupied by his anchors”?) and the planet only has one life.
Is there a choice to be made or, as is often the case, should the imperative of moderation and balance have the last word? At least, we’ll leave it to him. Perhaps without concluding.