Coral reefs killed by climate change
Putting your head under water on the Great Barrier Reef is looking straight into another world:?the explosion of color, the shapes of the corals and the intense and quick movements of fish in amazingly bright and unexpected spectra of color and character. Some swim solo and some in shoals.
Australia’s vast coral reef on the northeast coast is truly unique and as such listed as World Heritage. But, as all warm water reef building corals worldwide, this important ecosystem is most acutely under threat. The heaviest burdens are warmer water caused by climate change, ocean acidification and pollution.
However, there is hope, according to Nick Heath, Program Leader at WWF Australia.
“I’m happy to say that many reefs are still healthy. But unfortunately up to 700 reefs are at risk from land-based pollution,” he says. Up to 90 percent of this pollution is from farming — the annual wet season floods the Reef with farm pesticide, fertilizer and mud runoff.
One good sign is that the Australian government and the state government of Queensland have committed to cut pollution by 50 percent by 2013. If successful, less pollution will help make the reef become more resilient to global warming and acidification of the ocean, although it will take time.
“So it might get worse before it gets better. It may not be enough, and we may ultimately have to cut water pollution by up to 80 percent by 2020 to save the reef,” says Nick Heath.
Corals are delicate. Warmer and acidic water leads to bleaching of the corals. Farming and cutting down rainforest close to the coast leads to pollution and sediment washing into the sea and “smothering” corals that need light to grow. The inner reefs are worst hit by this and also in worse shape than the outer reefs in the north and south.
Seafood caught on the Great Barrier Reef may end up on your dinner plate. Here are some keys to making sustainable choices:
» Avoid: Species that are long-lived (over 20 years), deep sea living, slow growing, late to sexually maturity, have few young and are big. Example: Sharks, whales, sea turtle and tuna.
» Better choice: Species that are small, fast growing, mature and multiply quickly and are very productive. Example: Oysters and possibly prawns — but ask about by-catch rates.