Protect coral reefs - don't buy an SUV

August 29, 2003 - The connection may seem tenuous - after all, how could driving an SUV have anything to do with protecting coral reefs? But it does. SUVs are big-time gas guzzlers, adding substantially to the problem of global warming, and it's killing our coral.

According to a recent report in the journal Science, "The link between increased greenhouse gases, climate change, and regional-scale bleaching of corals, considered dubious by many reef researchers only 10 to 20 years ago, is now incontrovertible." The report is just one of four published in a special series on the state of the world's coral reefs - and although the situation is grim, there is some hope that we can still save the most diverse ecosystems in our oceans.

The amazing diversity of coral reefs was celebrated this summer in the hit children's movie Finding Nemo. Reefs really can be that colourful and teeming with life. But as beautiful as they are, they are far more important to humanity for the services they provide. Coral reefs act as safe havens for food fish to reproduce and grow. And reefs are a potential treasure trove of natural chemicals that could be useful for people. AZT, used to fight HIV, is just one of these.

Unfortunately, reefs are also seriously threatened. About 30 per cent worldwide have been badly damaged, and it's estimated that 60 per cent could be lost in the next 25 years unless quick action is taken to help protect them. That will be no easy task, as coral faces a complex array of threats.
Consider the wildfires that engulfed large parts of Indonesia in 1998. On the island of Sumatra alone, more than 15,000 square kilometres burned - that's 10 times the size of the giant fires that have burned in British Columbia this summer.

All that fire created a huge plume of smoke and ash that settled over the Mentawai Islands in the Indian Ocean. So much ash ended up in the water that it greatly added to the amount of available nutrients and caused a red tide that killed off almost 100 per cent of the Mentawai reef.

In this case, tropical wildfires could be said to have been the root cause of the reef's death. But these fires were hardly "natural." Such massive wildfires are actually a new phenomenon and those in 1997-98 were the worst in history. They were brought on by a year of drought combined with huge amounts of logging and land clearing that had been occurring throughout Indonesia. As we change our climate and expand logging, such fires are likely to become more common.

Indonesia wasn't the only place where coral died in 1998. The El Nino event that year increased water temperatures throughout the tropical Pacific, killing 16 per cent of the world's corals. Warm water puts stress on coral and causes it to expel the algae - called zooxanthellae - with which it shares a mutually beneficial relationship. This causes the coral to turn white or "bleach" and often die.

It is believed that coral and their zooxanthellae evolved near the limit of their temperature tolerance, so it does not take much of an increase in water temperatures to see increased bleaching. As our climate warms, these tolerance levels are likely to be surpassed with increased frequency. Combined with other stresses, such as overfishing, dynamite fishing and cyanide fishing, corals are faced with an increasingly dire future. One paper concludes: "Our results demonstrate that coral reef ecosystems will not survive for more than a few decades unless they are promptly and massively protected from human exploitation."

To do that, researchers recommend that at least 30 per cent of all coral reefs be declared "no-take" zones where fishing is prohibited. Although this will not protect coral from global warming, it will reduce other stresses and could help some coral adapt to warming waters. In the long term, however, we will have to choose between our energy-hogging SUVs and coal-burning power plants, and the coral reefs that provide us with so much more.

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