Caribbean Coral Reefs 'Flattened' Over the Past 40 Years

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A coral reef off the coast of Haiti. Photo by Franco Caruzzo via

You know those underwater pictures of pretty branched coral rising up from reefs in the Caribbean? Well that lovely coral is all but gone. Not disappearing, gone—on more than 75 percent of coral reefs in the Caribbean.

Recent research suggests branched coral, which looks like underwater trees, has been replaced by short, rival species. The culprit? In part, climate change.

Researchers from the University of East Anglia poured over 500 surveys from the past 40 years. About 200 Caribbean reefs were included in the surveys examined. Researchers discovered that the "flattening" of the reefs began in the late 1970s when white-band disease plagued reefs, killing 90 percent of elkhorn and staghorn corals—some of the most spectacular of the branched bunch.

Then a decade ago, most of the remaining branched coral was killed by widespread bleaching. Bleaching occurs when coral expel algae, usually because the water temperature is too warm, which we know is linked to climate change.

So-called weedy coral species—small, with short life spans—moved in and choked out the miniscule populations of branched coral that had somehow survived.

Branched coral is now found on fewer than 25 percent of Caribbean reefs, a stark contrast to the relatively healthy reefs in the Indian Pacific, where human habitation is sparse.

Why Branched Coral Counts

Aside from the fact that many Caribbean coral species could soon be facing extinction, branched coral is important for the oceans and for ocean communities. It helps reduce the energy of waves, so fewer big waves crash onto shores, and it is home for many species of reef fish. And when a habitat disappears, the fish usually do too.

::Via New Scientist