Massive Iceberg Runs Aground Near South Georgia, Impacting Wildlife and Ocean Life

The world’s largest iceberg has become stuck in shallow waters near the remote British island of South Georgia, a habitat for millions of seals and penguins.

This massive iceberg, approximately twice the size of Greater London, appears to have lodged itself near the island’s southwestern shores. As it remains in place, it is expected to begin breaking apart.

Fishermen are concerned about navigating through large chunks of ice, while some macaroni penguins that rely on feeding in the area may be affected. However, Antarctic scientists suggest that as the iceberg melts, it will release significant nutrients into the ocean, potentially fostering a surge of marine life.

“It’s like dropping a nutrient bomb into the middle of an empty desert,” said Prof. Nadine Johnston of the British Antarctic Survey.

Mark Belchier, an ecologist who advises South Georgia’s government, warned of potential risks. “If it breaks up, the resulting icebergs are likely to present a hazard to vessels as they move in the local currents and could restrict vessels’ access to local fishing grounds,” he said.

This event is the latest chapter in a nearly 40-year-long journey that began when the iceberg calved from the Filchner–Ronne Ice Shelf in 1986. Scientists have been tracking its movement through satellite imagery, particularly since December when it finally escaped an ocean vortex that had trapped it for years.

As the iceberg drifted northward through warmer waters known as “iceberg alley,” it largely retained its structure. At one point, it seemed to rotate in place before accelerating in mid-February, moving about 20 miles (30 km) per day.

“The future of all icebergs is that they will die. It’s very surprising to see that A23a has lasted this long and only lost about a quarter of its area,” said Prof. Huw Griffiths, who spoke to BBC News from the Sir David Attenborough polar research vessel currently stationed in Antarctica.

On Saturday, the towering 300-meter ice mass struck the shallow continental shelf roughly 50 miles (80 km) from the island and now appears to be firmly grounded.

“It’s probably going to stay more or less where it is until chunks break off,” said Prof. Andrew Meijers of the British Antarctic Survey.

The iceberg is displaying clear signs of deterioration. Initially covering an area of 3,900 square kilometers (1,500 square miles), it has steadily decreased in size, shedding significant amounts of water as it has traveled through warmer seas. Its current estimated size is 3,234 square kilometers.

“Instead of a big, sheer, pristine box of ice, you can see caverns under the edges,” Prof. Meijers noted.

As the tides lift and lower the iceberg, the friction against the continental shelf will cause it to grind back and forth, eroding both ice and rock.

“If the ice underneath is rotten—eroded by salt—it’ll crumble away under stress and maybe drift somewhere more shallow,” Prof. Meijers explained.

Beneath the iceberg, an entire ecosystem of small marine creatures, including corals, sponges, and sea slugs, faces destruction.

“Their entire universe is being bulldozed by a massive slab of ice scraping along the sea floor,” said Prof. Griffiths.

Although this is devastating in the short term, he pointed out that such events are a natural part of the region’s ecological cycle.

“Where it is destroying something in one place, it’s providing nutrients and food in other places,” he added.

Concerns had initially been raised regarding the impact on the island’s larger wildlife. A similar event in 2004, when an iceberg lodged in the Ross Sea, negatively affected penguin breeding and resulted in increased mortality.

However, experts now believe that most of South Georgia’s wildlife will not face the same fate.

Peter Fretwell from the British Antarctic Survey noted that some macaroni penguins that forage on the continental shelf where the iceberg is grounded may experience disruption.

As the iceberg releases freshwater into the surrounding saltwater, it could decrease the availability of krill, a primary food source for penguins.

While the penguins might relocate to other feeding areas, doing so would place them in competition with other marine species.

The iceberg could also pose logistical challenges when the fishing season begins in April, potentially obstructing harbors and complicating navigation.

“This will be the most ice from an iceberg we will have ever dealt with in a fishing season, but we are well-prepared and resourced,” said Andrew Newman of Argos Froyanes.

Despite the challenges, researchers in Antarctica are also uncovering the critical role icebergs play in sustaining marine ecosystems.

Prof. Griffiths and Prof. Johnston, aboard the Sir David Attenborough research vessel, are studying how nutrients from Antarctic ice circulate across the planet.

They explain that various particles and minerals become trapped in ice and are gradually released into the ocean as the iceberg melts.

“Without ice, we wouldn’t have these ecosystems. They are some of the most productive in the world, and support huge numbers of species and individual animals, and feed the biggest animals in the world like the blue whale,” said Prof. Griffiths.

One indicator that the nutrient release from iceberg A23a has begun will be the emergence of vast phytoplankton blooms around it. If this occurs, satellite images should capture a massive green halo surrounding the iceberg in the coming weeks and months.

The natural cycle of iceberg formation and melting is crucial to marine life. However, climate change is expected to accelerate the process, leading to increased instability in Antarctica’s ice sheets.

As temperatures rise, more icebergs could break away, melt at faster rates, and further disrupt wildlife and fishing industries in the region.