Human activities increase Caribbean reef threat

Using geographic information system (GIS) data to determine reef degradation, the report studied an area of around 10,000 square miles covering the entire Caribbean reef system.

Developments such as sewage discharge, water-based sediment and pollution coming from farms, marine-based pollution from sources such as cruise ships, and over-fishing were primarily taken into account, though natural phenomena such as hurricanes were also considered.

“We estimate that many of the region’s reefs are threatened from direct human pressures, such as over-fishing, runoff of pollution and sediments from the land,” lead author of Reefs at risk in the Caribbean Lauretta Burke stated.

“And the overreaching threats of coral bleaching from warming oceans, coral disease from new pathogens and ravages of increased hurricane frequency are additional threats that put even more reefs at risk.”

The report also showed that the Caribbean’s natural reefs provided shoreline protection from extreme weather by dissipating wave and storm energy, saving between US $700 million and US $2.2 billion every year.

Dive tourism also generates around US $2.1 billion for the region each year, but WRI warned that reef degradation could cause this to be cut by around US $300 million annually by 2015 if nothing was done to preserve the coral.

Filmmaker Jean-Michel Cousteau said in support of the report: “Human activity has undermined the health and vitality of reefs. The coral reefs I observed in the 1940s are totally different today, and sadly, none of those changes are for the better.”

The WRI’s Reefs at Risk Index has been used to measure threats in Southeast Asia, the centre of global marine diversity, but this is the first time it has been applied to the Caribbean or used in an area that is heavily dependent on tourism for its revenue.

“We have only rated 64% of the Caribbean’s tropical coral reefs as threatened, compared to 88% of those in SouthEast Asia,” Mr Burke said. “However, the threat of disease, which is not included in the model, is far greater in the Caribbean.”

By Jane Kettle