Reefs at Risk Revisited

A new report draws a global map of the threats facing coral reefs today
11 March 2011


Reefs at Risk Revisited map thumb


Helen - This month saw the launch of a major new report on coral reefs. Reefs at Risk Revisited has compiled a detailed global map of the problems these vital ecosystems are facing today.

The report was launched this month at a special meeting at the Royal Society in London, and I went along to meet some of the people behind the report.

The main headline findings are rather depressing. One of the report authors is Mark Spalding from the Nature Conservancy.Bleached Coral

Mark - The top headline is that 75% of the world's coral reefs are now threatened by human actions. That includes a combination of the direct imapcts of people on reefs, things that we can control really at relatively local levels. Those direct impacts are affecting 60, just over 60% of the world's reefs. When we factor in recent climate change, this is what's happened to date, not the future, that pushes our number up to 75% of the world's reefs.

Another headline that we looked at was predictions of the impacts of future climate change. And we sat those, if you like, on top of the results of threat to date, and they become extremely gloomy. By the 2030's we're up to 80% of the world's coral reefs being threatened and by the 2050's we're at 99%.

You can't stick your head underwater everywhere in the world, there's to much, there's not enough scientists, some of these places are very remote. So instead we've built a model which predicts how much is threatened and we've had that verified by hundreds of scientists from around the world.

Helen - And in terms of what's causing this risk to reefs, what are the threats we're looking at? What are reefs suffering from today?

Mark - It's a huge host of threats, really and quite often one piled on top of another. The biggest one is certainly unsustainable fishing. Just taking too much and sometimes taking it in extremely damaging ways using explosives to catch fish.

On top of that we have what's washing off the land. We have sediments and pollutants just being washed out of agricultural areas, from deforested slopes, into rivers and out onto the reefs. So that's kind of the watershed threat.

Then we've got coastal development. Human populations are burgeoning everywhere but particularly in the coastal zone. And as buildings are built and sewage is pumped into the ocean, that's a huge threat.

And the final local threat is shipping and other sources of marine pollution, oil and gas installations, boats cross-crossing the oceans and so on.

And sadly what we've added to that, already that long litany of threat, is the issue of chancing climate, changing oceanography.

Helen - And talking about reefs at risk, what does that really mean? Are we talking the reefs that are at risk aren't going to be here in a number of years time? How do we get a handle on what that actually means in the real world?

Mark - We need to remember this is a mode. We're trying to predict the condition and if you stuck your head under the water in many of these places you'd see different things. In some cases it is a measure of things already declining but in all cases it's a measure of potential for decline that could be any day, the pressures are immense.

Helen - Mark Spalding there introducing the key points raised by the Reefs at Risk Revisited report about the threats facing coral reefs today.

This new report follows on from a previous Reefs at Risk report that originally took on the challenge of painting a global picture of coral reef threats. Kristian Teleki chaired the Reefs at Risk Revisited launch. I spoke to him about how the whole thing got started.

Krisitian - Reefs at Risk got started in 1996-1997 when a number of scientists got together and were concerned that they weren't having enough information about all the things that were happening around the world on coral reefs. So they got together and they thought let's put this analysis together and we'll do a quick assessment of the entire world's reefs and are they are threat based on these different levels of threat indicators.

And that came up with some really useful statistics, and it actually boiled it down to these two or three key statistics that were cited over and over again. And we know that it's been cited over 400 times in the scientific literature, but it's been cited thousands and thousands of times and I remember seeing this constantly being recycled in the press in the media about these statistics.

And so really it was in thinking, in my previous job as the director for the International Coral Reef Action Network, that this was a great opportunity to revisit these statistics and update them. Because a lot has changed, both in the ecosystems, in the climate, and at a political level. So it was really important to go back and have a look at this but also not only compare the statistics but revisit some new nuances about social vulnerability, climate change, ocean acidification, these key threats to the importance of coral reefs. 

So, it really was the revisited that we thought that this would make a really interesting story to revisit these old statistics.


Helen - And I assume, am I right that generally the changing picture since '98 is one 

Kristian - Sure, I think there's been a general net decline in reef health, there's not doubt about that.  You don't have to be a rocket scientist to go out and look and see that there's an impact.

I think the message is that it's not a straightforward story. I remember when we did work in the Seychelles in 1998 during the peak of the bleaching event, we went out in the southern Seychelles and we actually found that there was a lot of heterogeneity and mixed responses in terms of the bleaching event. Some reefs were bleached, some died, some didn't. And in fact, that told a very interesting story because when we came back the big story was all reefs are dying in the Indian Ocean, well that wasn't actually true.

Table CoralSo, I think what this report highlights is that there are pockets and areas that are resilient for one reason of another, they're doing well for one reason of another, and we really need to look at those very carefully as potential seed banks for other parts of the ocean.

Yes, while the net message is a depressing one, I think we're finding more and more cases where there are areas of hope and we really need to look at those carefully, because we can do something about it.

Find out more

Reefs at Risk Revisited website

Reefs at Risk Revisited report (Download PDF)

Interactive global map


Add a comment