Posts Tagged ‘Australia’

Caribbean reefs ‘flattened’ in just 40 years

June 11, 2009

In just 40 years, the Caribbean’s spectacular branched corals have been flattened. Research reveals that the corals have been replaced by shorter rival species — and points to climate change as at least partly to blame.

Most of the reefs have lost all the intricate, tree-like corals that until the 1970s provided sanctuary for unique reef fish and other creatures, as well as protecting coastlines by sapping the energy of waves.

Coral diversity is important for both the many species that swell on reefs and for coastal protection, says Jennifer Gill of the University of East Anglia and a member of the research team.

She and her colleagues analysed data over the past 40 years from 500 surveys of 200 Caribbean reefs. They say that the flattening process took place in two main phases. Firstly, in the late 1970s, a condition called white-band disease swept through the reefs, killing 90 per cent of the most spectacular tree-like elkhorn and staghorn corals.

The second phase, in 1998, saw many of the remaining tree-like corals being wiped out during a massive bleaching event, probably driven by global warming.

Different corals — fast-growing but short-lived “weedy” species — then took over the reefs, outcompeting most of the remaining tree-like corals. The researchers found that flat reefs now cover 75 per cent of the Caribbean, compared to just 20 per cent in the 1970s.