The State of the World's Reefs: A Coral Scientist Explainsclimate change, marine, Science


Yesterday, Leah Bunce Karrer reported back from the 2012 International Coral Reef Symposium (ICRS) in Australia, where scientists are discussing the latest findings on coral reef health. CI Senior Fellow Les Kaufman gives his take on some of these worrying studies.

Last year a roomful of “reefophiles” gathered at a press conference in Washington, D.C. for the release of “Reefs at Risk Revisited”, a 10-year retrospective on changes in coral reef health around the world compiled by Lauretta Burke and her team at the World Resources Institute.

Being among those in the room who had contributed data to the compendium, I shouldn’t have been surprised at the bottom line, though it still came as a bit of a shock: nearly two-thirds of the world’s coral reefs were already seriously threatened by local stressors — in addition to the looming, rapidly worsening weight of climate change.

Over the past year, I joined a group of colleagues in crafting a global scientific statement on the future of coral reefs based on the sum of knowledge of reefs’ history over the past several hundred million years. This document — signed by a big chunk of the world’s coral reef science community — was just released to the world at the 2012 ICRS in Cairns, Australia.

Overall, we concluded that coral reefs are astonishingly resilient and have survived devastating blows from natural disasters in the past … but with two nagging caveats.

First, it took hundreds of thousands to millions of years for reefs to recover from each large blow. Second — and much worse — Earth’s coral reef communities had suffered high temperatures or low pH, but never the two together as is happening today. The complexity of rapid changes that we are seeing right now — changes in climate and ocean chemistry layered on top of overfishing and coastal pollution — is entirely unprecedented in the history of our planet.

None of this science was news to me. Still, sometimes it takes just one more piece of news along the same lines, and suddenly you begin to see the whole world in a different light … or dark. Here’s that additional piece of news.

Many reef scientists have long taken heart from the beauty and resilience exhibited by reefs in the Coral Triangle: a bulls-eye of marine biodiversity centered in the Philippines and Indonesia. Some of us figured that the coral reef “heartland” was generally in good shape, and maybe even able to take a beating.

Wrong. The condition of coral reefs in the Coral Triangle is declining precipitously, just like everywhere else — and possibly just a bit faster and harder. And we’re losing a lot more than television eye candy. Imagine that you are one of the millions of people who live near and completely depend upon a coral reef for fish, tourism income, coastal protection and other services. The list of bedfellows to coral reef loss is frightening: poverty, starvation, disease, catastrophic loss of wealth, severe damage to coastal infrastructure and the loss of a promising source of new pharmaceutical drugs. These losses would close Earth’s richest window on the secrets of life itself.

Check out the World Resources Institute’s animated video “Coral Reefs… Polyps in Peril” to learn more about these unique ecosystems.

But here’s the good news: we know what we have to do. Political pressure to curtail greenhouse gas emissions must continue, double time; the push to return CO2 emissions to 350 parts per million is no joke when it’s already past 390 and heading for 700 by 2100.

But the small-scale stuff matters too. Every village that protects its reefs and mangroves, fishes sustainably and takes care to steward the watersheds and forests that shield and feed it — this is a village that is steeling its coral reefs to weather the climatological storm breaking upon all of our shores

We can each be a part of a great human bulwark against the worst effects of climate change. By doing the things we should have been doing all along, we can build ecosystem resilience and buy time against climate change impacts. All we have to do is help nature to keep our water clean, our air fresh and our ecosystems healthy and nurturing by not interfering with these precious processes that we so often take for granted.

As conservation scientists put it, we must keep our ecosystem services flowing. The way to begin is to stop eroding these systems, and instead foster the growth of nature’s innate defenses against violent storms and sea level rise.

By not overfishing, the coral reefs’ own doctors — literally, doctorfishes, parrotfishes and others — can keep corals free of seaweed and other threats to their health. By stemming the flow of pollutants into coastal waters, we give coral reefs the chance to rebuild their collective immune system, yielding better odds that reefs can weather climate fluctuations. By stepping our infrastructure back from the shore, we reduce our exposure and costs, while also unleashing the natural resilience and regenerative forces of coastal habitats, unhindered by inflexible concrete.

There is no question that the climate is still changing dangerously, and will for quite some time even after the beginnings of our best efforts to gentle it. However, if we remove local stressors while moving rapidly to reduce our CO2 emissions, there will be an excellent chance that coral reefs, in all their massive importance to humanity, can squeak through and continue to be there for us. The benefits will start immediately, and only increase with time. It’s logical. It’s simple. It’s what we’ve got to do.

Les Kaufman is a senior fellow in CI’s Science and Knowledge division.


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