Saving Marion Island’s Seabirds
Marion Island, the larger of the two sub-Antarctic Prince Edward Islands, is a critical breeding ground for seabirds and wildlife, including half of the world's Wandering Albatrosses. However, the island faces a severe threat from House Mice, unintentionally introduced in the 19th century. A warmer, drier climate has led to an increase in mice populations, causing them to turn to seabirds as an alternative food source. The birds, having no defence against the attacks, are at risk of local extinction if the situation continues unchecked.
The South African Department of Forestry, Fisheries, and the Environment, in collaboration with BirdLife South Africa, is working to implement an ambitious project, The Ambitious Mission of the Mouse-Free Marion Project, to remove the mice and restore Marion Island’s ecosystem. Wilfred Chivel, CEO of Marine Dynamics and Founder of the Dyer Island Conservation Trust, welcomed Dr Anton Wolfaardt as quest speaker during a recent Marine Evening at the Great White House. Dr Wolfaardt is the Project Manager of the Mouse-Free Marion Project and presented a powerful vision for Marion Island - a South African sub-Antarctic treasure - united by a common goal: to restore its ecosystem by eradicating invasive house mice. This ambitious conservation initiative aims to address the devastating impact of these non-native rodents on the island’s fragile ecosystem and to protect Marion’s unique seabird populations from local extinction.
“The Mouse-Free Marion Project is preparing for one of the most challenging eradication operations in conservation history,” Dr Wolfaardt said. “Scheduled for the winter season, when seabird breeding is at a low point, the project plans to employ aerial baiting - using helicopters to systematically distribute rodenticide bait across the island’s 30,000-hectare terrain.” He continued: “Precision is essential; the baiting must be thorough, with no gaps, to ensure that all mice are eradicated - even a single pregnant mouse surviving the baiting could repopulate the island.” Dr Wolfaardt acknowledged the inherent risks of the operation, including potential impacts on non-target species. However, he emphasized that rigorous studies and planning have gone into selecting bait that is effective against mice but minimizes harm to other wildlife. The bait must also be weather-resistant to remain effective during the island’s rainy winter months.
Mouse-Free Marion Project could bring transformative ecological benefits. Removing the invasive mice would enable seabirds, such as the wandering and grey-headed albatrosses, to nest safely, free from predation. This would also allow native invertebrates, crucial for nutrient cycling, to recover, restoring the island’s ecological balance. As one of the few sub-Antarctic islands, Marion provides essential breeding grounds for large seabird populations and is home to four species of penguins, numerous albatrosses, petrels, and skuas, among others. The wandering albatross, for instance, relies on Marion Island for over 25% of its global breeding population. Marion also hosts two species of fur seals and significant populations of sub-Antarctic elephant seals, as well as a thriving marine ecosystem that includes orcas and other marine mammals. Dr Wolfaardt emphasized the urgency of this work, not only for Marion Island but for the future of biodiversity conservation worldwide.
(Original article shortened - Editor)
Marine Dynamics
