Picture yourself diving in the clear blue waters of the Caribbean, swimming among the waving braches of coral on an offshore reef.
It’s an image of paradise – but the results of a new study show that the region’s coral reefs, in common with those across much of the rest of the world, aren’t growing as much as they used to.
What’s Happening to the Caribbean Reefs?
Reefs are composed of living organisms – corals – and when the organisms die off, their skeletons remain behind for other corals to affix to, gradually building up a solid carbonate reef structure.
In this study, the researchers evaluated current growth rates from over a hundred sites on reefs across the Caribbean and compared them with historical values. Their findings are alarming – although most of the reefs are still building, the growth rate is noticeably lower than in the past.
“We have to put it in context,” the study’s lead author, Professor Chris Perry told Decoded Science. “The message that reefs are in decline isn’t a new one but it is especially bad in the Caribbean.” And the loss of the reefs’ ability to increase vertically is important, because the slow growth limits their capability to respond to environmental stimuli – and environmental change.
There are many possible reasons for the decline, not all of them human-induced – though some certainly are. The Caribbean, for example, suffers from overfishing which alters the ecology of the reefs. Global increases in sea surface temperatures cause bleaching, killing off large numbers of the living organisms, while local or regional disease outbreaks are also likely to be influential. But a key part of the problem, according to Professor Perry, is that many of the corals which are disappearing are those which are key reef-builders.