People tend to think of invasive species as living things that leap from continent to continent, somehow reaching over the vast expanses of ocean. The island of Tristan Da Cunha, however, is dealing with another sort of invasive species problem.

Tristan Da Cunha is part of one of the most isolated island groups in the world, sitting well below the Tropic of Capricorn in the South Atlantic Ocean. Fewer than 300 people, British citizens, live on the island, and there’s only one regularly scheduled boat that arrives at the island just one time per year.

A recently published study of the consequences an unintended arrival at Tristan Da Cunha reveals the way the offshore oil drilling operations can create negative environmental impacts far beyond the occasional oil spill. The Tristan Times reports that 62 non-native species were introduced to the waters around Tristan Da Cunha by just one incident.

In 2007 decommissioned oil rig being towed from Brazil to Singapore encountered rough seas and was abandoned by the company that was moving it. The rig ran aground on Tristan Da Cunha, and brought with it almost an entire reef community of living things. An arrival like that doesn’t just carry macro-organisms that scientists can easily find and count, but potentially pathogenic micro-organisms too. Another crashed oil rig could bring with it a pathogen that decimates the Tristan rock lobster, a crustacean unique to the waters around Tristan Da Cunha.

Such an event would ruin the human settlement of Tristan Da Cunha as well. It’s the harvest of the rock lobster that enables the community of Tristanians to remain self-sufficient.

Tags: invasive species, island, oceans, offshore drilling, oil, tristan da cunha