Erstellt am: 1. 6. 2016 - 15:32 Uhr
"This is animals dying en masse"
The devastating episode of coral bleaching that has been sweeping the world’s tropical oceans now has destroyed large parts of the previously pristine coral reefs in the Maldives.
It’s another alarming reality about the state of our rapidly warming oceans.
“It’s incredibly sad to go and see this on a scale that we’ve been seeing it at,” says Richard Vevers, the founder of the Ocean Agency, who has been documenting the destruction on the Maldives. His team has been following what is known as the third global bleaching event since it started in October 2014. “We’ve been to so many locations and every time you get into the water it really hits you that this is animals dying on mass. It has been quite disturbing.
XL Catlin Seaview Survey
Oceans are absorbing about 93% of the increase in the Earth's heat. The temperature increases but the corals under stress, which drive out the algae known as zooxanthellae that give them colour.
As Vevers puts it “The corals are animals and their flesh is actually coloured. During the bleaching process that flesh turns clear and so you are seeing the skeleton glowing white.”
Vevers describes the “spectacular sight” of the once kaleidoscopic coral reefs turned “bright white”.. Often, in the locations that the Ocean Agency team document the corals haven’t been in a good condition for a long time. This means you don’t have such clear water. But, before this episode of bleaching, the reefs of the Maldives had been very healthy and so, in the crystal clear water, the team could see the intensity of the bleaching in all its vivid horror.
XL Catlin Seaview Survey
The population of the Maldives is largely dependent on the health of the reefs – for its tourism industry and as as a wave-break that helps prevent inundation on low-lying islands that are already imperilled by rise water levels. So the danger to the reefs is a double-punch from climate change.
Coral bleaching is also expected to have a disastrous impact on the regions fisheries, explains Richard Vevers: “The scientists say that about a quarter of all marine fish rely on coral reefs. They are the nursery of the sea. When you lose these areas the structure collapses and the juvenile fish have nowhere to hide so they can get picked off really quickly. You can see a collapse of the fish population very quickly.”
In all, it’s estimated that 500 million people are reliant on coral reefs for their economic survival and yet this current bleaching event could be just the beginning of a much more widespread ecological disaster.
XL Catlin Seaview Survey
The bleaching is exacerbated by El Nino - but make no mistake, say scientists, this is linked to the ocean warming effect of excess carbon in the atmosphere.
As Ocean Agency puts it "Global Bleaching Events are a new phenomenon caused by this additional heat (there have only been three in recorded history - all within the last 20 years)"
The previous episodes hit our oceans in 1998 and 2010, but this one has lasted much longer than either of the last two and has been more destructive. Even if the global efforts to control climate change are gathering pace, in the short term we can expect the situation to get much worse before it gets any better because of the global warming already in the Earth's system.
“We are committed to at least another 20 or 30 years of warming oceans. We know that bleaching events are going to be more frequent and they are going to become more intense in the years to come. It is not looking like a very pretty picture for coral reefs across the world.
The most depressing aspect of this story, I find, is that we might have left it too late to save many of the world’s corals – the jewels in the crown of marine biodiversity. At the Paris Climate Conference in December the world agreed to try and contain global warming to a peak of 2 degrees above pre-industrial levels - with the ultimate ambition of keeping the rise to just 1.5 degrees. But, even if the plan succeeds, that is just an average rise:
XL Catlin Seaview Survey
“The scientists say coral reefs could cope with a rise of up to 1.5 degrees centigrade rise in temperature. There will be pockets around the world the ocean doesn’t warm quite as much as other areas. But in some places, in my view, we are going to go beyond the 1.5 degrees rise. So it is really is about finding the locations where we can protect the reefs and putting measures to protect them for the future.”