The finding, reported in this week's Nature, suggests that even small residual amounts of oil are enough to seriously damage marine wildlife.
The tanker Jessica ran aground off the Galápagos Islands, off the coast of Ecuador, in January 2001. The weather carried the spilt oil away from the coast, and the islands were generally viewed as having had a lucky escape.
But this study, by Martin Wikelski of Princeton University, New Jersey, and colleagues shows that 62 per cent of the marine iguanas on Santa Fe island, close to the spill, died in the following year, compared with none on an island that escaped pollution.
The researchers suggest that small amounts of oil killed microbes in the iguanas' guts that enable the animals to digest algae, causing them to starve.
As a consequence of the oil spill, some of them research team's earlier experiments on the marine iguanas — dating back to 1987 — have been terminated. Wikelski is currently seeking US$600,000 in damages from the Ecuadorian state oil company as part of a wider, US$14-million claim being made by the Galápagos National Park.
Link to Nature news article 'Ecologist sues over wrecked iguana study'
Link to Wikelski et al's article in Nature
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