Good news for some corals, not so good elsewhere
Some of the world’s corals may be able to escape destruction under climate change according to an international team of scientists studying a coral reef off Moorea, a French Polynesian island in the Pacific.
Coral reefs off Moorea, Tahiti, have been able to rebound from bleaching events.
Credit: iStockphoto/Xavier Marchant
The researchers found that the corals rebounded on five occasions in the past 18 years despite sustaining heavy damage from four bleaching events and one cyclone.
Team member Dr Lucie Penin of the ARC Centre of Excellence for Coral Reef Studies in Townsville says the corals were even able to recover after the reef had been swamped by weeds.
However, she points out that the corals studied lie on the outer reef slope, that Moorea is not heavily populated, and that the main human impact has been fishing. The team concluded that the lack of human pressure and relatively low levels of pollution have been key factors contributing to the reef’s resilience.
Dr Penin says that in the early 1990s, seaweeds had taken over more than half of the reef in the wake of cyclone and bleaching damage. However, key coral species were able to re-colonise the reef in subsequent years. ‘It shows that a fast recovery, in just a decade, is possible under the right conditions,’ she adds.
The IUCN, however, offers a less optimistic outlook. In a recent detailed analysis of its 2008 ‘Red List of Threatened Species’ it concluded that many marine species are experiencing potentially irreversible loss due to over-fishing, climate change, invasive species, coastal development and pollution.
This includes at least 17 per cent of the world’s 1045 shark and ray species, six of the seven marine turtle species and at least 27 per cent of the 845 species of reef-building corals. The analysis of the 44 838 species on the IUCN Red List showed that at least 16 928 species are threatened with extinction.