The new Reefs at Risk Revisited report is out — 13 years after the original Reefs at Risk, which was the first global assessment of the threats to Earth’s coral reefs and painted an alarming picture of their future. Today’s edition is even less rosy: It reports that 75% of the planet’s reefs are threatened, not just by unsustainable fishing practices and development but also by the effects of climate change.

Amazingly, Mark Spalding, Conservancy marine scientist and a co-author for both editions, is still optimistic we can save coral reefs. I asked him why and to tell us what’s in the new report.


You were part of the first Reefs at Risk report, published more than a decade ago. What’s changed? Are things that much worse for coral reefs now — and why?

MARK SPALDING: The 1998 report was a wakeup call. It was the first reliable assessment of the scale of the problems facing reefs, and we found those problems — such as unsustainable fishing, coastal development, pollution and sediments sweeping off the land — were truly global and piling up to create huge challenges.

Our findings spurred vast efforts that spent hundreds of millions of dollars to deal with these problems. But while I’d love to tell you we’ve turned things around over the last decade, we haven’t. In fact, there’s been a 30% increase in the area of threatened reefs. Oceans have warmed because of climate change, and that’s caused devastating coral bleaching in many areas.

It would be wrong to talk about failure, though. Reefs would be in much worse condition in many places if we hadn’t done what we’ve done. There are now literally thousands of examples of good reef management worldwide, and of how to turn coral reefs around. We need to pick up these examples and see them as a tool-kit, something we can turn into standard management practice across the globe. For peoples’ sake.

The report says 75% of the world’s reefs are threatened. What does “threatened” mean, exactly — are they on the verge of disappearing, or no longer functioning?

SPALDING: A bit of both. Some of our “threatened” reefs are to all intents and purposes lost, while others on the map still appear to be in good health. But most of that 75% are degraded to some degree: fewer fish, fewer corals, banks of seaweed smothering the sea floor.

Reefs at Risk isn’t a measure of conditions in the water — it’s a scientific best estimate of how things could affect reefs. In some cases, these threats are like shadows, waiting in the wings; elsewhere, they have begun to tip the balance. And as these reefs decline, coastal people start to lose out too — from declines in fishing, failing tourism revenues, or weakening protection against storms by the ramparts of living reef.

If you had to pick one threat that’s gotten dramatically worse over the last 10 years, which would it be?

SPALDING: Coral bleaching, without a doubt. Bleaching is a stress response: when the water gets just a bit too warm, the corals pale to a bleached white and lose the important algae that normally live inside their bodies. Bleaching can kill corals over vast areas in extreme cases.

We knew bleaching was a threat as we worked on the last study, but no reef scientist had predicted the scale of the problem. It has just come on so fast, so strong — it’s hammered many reefs, and left other corals more susceptible to disease or other impacts.

Recent bleaching has increased the percentage of threatened reefs from 61% to 75%. Future projections of bleaching’s effects are even scarier. Until we get global change and carbon emissions under control, the threats from coral bleaching — and ocean acidification, as the ocean absorbs more CO2 — will continue and accelerate.

Let’s do a thought experiment: Coral reefs have vanished overnight. What are the results? What do we lose? Who suffers? How would it affect the developed world?

SPALDING: First off, the 275 million people who live near coral reefs would be devastated. There are 150,000 km of worldwide coastline sheltered behind reefs, which provide storm and wave protection. And these aren’t just people on remote islands — while coral reefs provide critical food and shelter for villages and farms, they’re also critical to the functioning of countless towns, businesses and even cities from Miami to Manila. There are entire nations built from coral reefs, whose land surface is nothing more than the accumulated remains of corals shaped into islands by storms and currents. So all that would go away.

But the ramifications are so much bigger than the local. Tourism, for one: Reef tourism is a massive industry, bringing international travellers to 100 coral reef nations around the world, and providing one-third of all export earnings to around 20 of these countries. And there are the vicarious benefits from the reefs’ supplies, from exotic food to aquarium fishes.

Equally important are the potent chemicals of the reefs and their medicinal uses and potential. Like rainforests, coral reefs host a bewildering diversity of plants and animals. In systems this diverse, the struggle for survival leads many species to develop complex adaptations, from skeletal structures to poisons and venoms. There might be 1 million different animal species on the world’s reefs, and we have only just begun to look at them. But they’ve already yielded active compounds with considerable promise for the treatment of certain cancers, HIV and malaria.

It’s frightening to think of coral reefs disappearing. The flip side: Give reefs a chance and the payback to people could be vast, and could continue in perpetuity.

The report calls for increased protection of coral reefs — but 27% of the world’s reefs are already inside marine protected areas (MPAs), and you write those aren’t completely effective. How do we increase the effectiveness of existing MPAs for reefs as well as their coverage?

SPALDING: It’s true. We found that only 6% of reefs were in fully effective MPAs — sites that allow fish and other organisms to thrive without any significant human impact. And quite a lot of those effective sites are very remote from the threats.

We know that MPAs are good for reefs. We also know that, as fish stocks recover in MPAs, they allow increased catches for fishers and better diving for tourists. So we need more MPAs close to people, precisely in the places that the threats are highest.

But these aren’t easy fixes – there is competition for use in these places, and some will resist any efforts to restrict or control fishing or other impacts. The Conservancy has been working around the world with fishers as well as with governments to design protected areas — and, indeed, comprehensive ocean zoning — to lead to benefits for all. Success breeds success in these matters, and the best emissaries for MPAs are their beneficiaries. Marine conservationists should be using fishers from successful locations to spread the word to others.

Given the dramatic decline in the condition of reefs since the last Reefs at Risk appeared, why should we be optimistic that we can avoid widespread disaster for coral reefs?

SPALDING: It would be foolish to simply wear a happy smile and pretend “all shall be well” — this report clearly points to a very sobering reality. But the report is also filled with success stories, everything from inspiring community leaders and well-managed local areas through to large-scale marine parks and international agreements such as the Micronesia Challenge. We can turn things around. We can manage reefs for survival, or even for rapid recovery. And in so doing, we can strengthen our coastlines and feed more hungry mouths.

Climate change hangs over such optimism, though — our projections suggest that reefs may be defenseless against its worst ravages. But we can certainly buy ourselves time. Some reefs have shown remarkable resilience and a great ability to bounce back from bleaching impacts to date, so if we can persuade the global community to act on climate change soon there’s certainly hope.

There are more than 60 recommendations in this new report for policymakers, scientists, industry. What can ordinary people do to help coral reefs? Anything?

SPALDING: Individuals have a critical part to play. If you live near a reef, get involved. Help local communities and organizations with reef conservation and lobby leaders for better management. Fish with due caution and be careful not to drive overfishing when you buy fish from others.

And even if you live far from reefs, you can help, too. Do you holiday in reef areas, or know people who do? Think about where you stay and don’t be afraid to ask questions — choose hotels and restaurants that do not pollute and that make a positive contribution to the environment. Support NGOs such as The Nature Conservancy, which are making a real difference to coral reef conservation on the ground. Reduce your own personal carbon footprint, too — this step is urgent and, while it won’t be enough, it sends a powerful message. Finally, tell others what you are doing and encourage them to do the same.

(Image: Bleached coral in waters off Phuket, Thailand. Image credit: Aeysea/Flickr through a Creative Commons license.)

If you believe in the work we’re doing, please lend a hand.


  1. just a quick note to add in the BBC series South Pacific, it was a joy to see coral farming in a programme that was otherwise fairly bleak about all the threats facing this particular and maybe most marine environments. While I’ve always been fond of them and been aware of their parlous state, I’ve recently added the shark as my special campaign creature. Or at least to do the little I can to help raise their profile. Sadly they’re not so obviously lovable as their mammal neighbours the whale, but to me far more interesting and possibly far more important to the marine ecosystem and even more in need of our support.

  2. My experience with coral reefs comes from extensive vacationing in Belize near the reefs and sailing and snorkling in the BVI’s. My observations are that reefs are the natural protective barriers for islands. Coral deposits begin to grow in beach areas where the surge current is best. Barrier reefs deposit calcium mounds until the surge current begins to get cut off or reduced. The ultimate destiny for a reef is to form a barrier island with a new reef forming just outside of it. I never see any attention paid to the dynamic development of a reef. Everyone looks to pollution or some static environmental cause for a reef to suffer. Increase the surge current and the reef will thrive. Cut channels or bore holes in reef structures to get the surge currents back.

  3. Marine Protected Areas which defend reefs from human interference, including offshore wind farm development, must surely be part of the answer to this devastation.

  4. We cannot afford to ignore that portion of our planet – oceans – and all the lives they support–whether we live near an ocean or thousands of miles away. As it is known that we only have explored about 5% of that part of our planet and are still making discoveries about life forms in it, we cannot afford to destroy what we yet do not know. Reverence for all life is key to our future.
    Reefs need attention and protection, but the whole human world
    will need to help

  5. Thank you for this information. I am a docent for the Wildlife Museum here in Parker, CO and we have a nice Coral Reef Exhibit. There is info I will share with our guests.

  6. Eugene, your comment about surge currents is fascinating. Can you point me to more background on this? Can it help protect against the bleaching that’s caused by increased acidification?

  7. I have not yet read this report so perhaps the answer for my question is in it. I hear the statement that warmer waters are causing bleaching of corals – as well as other factors. I would like to know if there is a consistent pattern for this particular factor or an inconsistent one. Does the report have a map of reefs and correlated maps with ocean temperature measurements? I would expect it to if it is making this statement. If there is an inconsistent picture at this time, what explanations are offered for this?

  8. Much like our freshwater streams, lakes and rivers, the oceans continue to be pressured by irresponsible development, global climate change, overfishing and a general ignorance to their fragility and importance to our species. The oceans can no longer be treated with abuse and degradation if we hope to avoid massive problems in the coming decades.

    It’s truly wonderful to see the work that TNC and other organizations are doing globally to help reverse the damage. From seeding coral reefs and establishing oyster beds to establishing MPAs, it’s great to know that such organizations are helping stem the tide of destruction and unsustainable practices that have gone on for far too long.

  9. Why is it Green People/Organizations don’t tote or acknowledge that the number one problem in the world is human overpopulation. We need to push effective birth control and raise the female literacy rate NOW. That will help save this world for all creates and us too!!

  10. It seems like we need some kind of miracle here. We need people to wake up to the effects of global warming so the right wing will stop lying about it. In a sense, we need the planet to speak…and speak loudly. We need some feedback from Nature…because otherwise, too many people will ignore this until it’s too late. That’s the reality. People respond to a crisis…but if the place burns down in a flash…then all of our hand wringing here won’t save the reefs.

    I’m glad Mark is optimistic. I wish I was more like him. I see the right wing continuing the campaign of misinformation on global warming and I just want to scream.

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