Hit by slime, Caribbean corals at risk of extinction

Loss of algae grazers could wipe out the corals in the next 20 years

 
By Moushumi Sharma
Last Updated: Monday 17 August 2015 | 08:59:26 AM

Caribbean coral reefs have declined by more than 50 per cent since 1970s

A UN report has revealed that most coral reefs in the Caribbean, hit by slime, could vanish in the next 20 years. This is because grazers such as colourful parrotfish and sea urchins, which feed on a slime of coral-smothering algae, are decreasing in number. Algae choke polyps, the tiny animals that build reefs with their stony skeletons. Parrotfish and urchins, which keep the algae in check, are the key to saving these corals.

The report, “Status and Trends of Caribbean Coral Reefs: 1970-2012”, maintains that climate change played only a minor role, despite past speculations that it was the main cause behind the reefs’ demise. “Climate change for me so far is 10 per cent of the story,” a media house quotes Jeremy Jackson, lead author of the report and senior adviser with the Swiss-based International Union for Conservation of Nature (IUCN), which issued the report with the UN Environment Programme and the Global Coral Reef Monitoring Network.

Differences of opinion persist. Mark Eakin, coral reef watch coordinator who contributed to the report, says it understates the impact of ocean warming. “It is something I would say they overlook in their studies. We really need to deal with climate change,” Eakin told the media house.

The report, which analyses surveys conducted by 90 coral experts over three years, says only one-sixth of the original coral cover is left, with Caribbean reefs having declined by more than 50 per cent since the 1970s. Jackson attributes it to overfishing, coastal degradation and diseases such as the mysterious 1983 urchin disease. The Caribbean has nearly 20,720 sq km of coral reefs, most of which are in poor health. These reefs generate an estimated $3 billion annually in tourism and fishing.

But all hope is not lost. The report says recovery is possible with restrictions on fishing and pollution. “Caribbean reefs are not a lost cause,” Carl Gustaf Lundin, director of the global marine and polar programme at IUCN, told the media house. Some of the healthiest reefs still have big populations of parrotfish, including off the US in the northern Gulf of Mexico, Bermuda and Bonaire. Most of these countries have “restricted or banned fishing practices that harm parrotfish, such as fish traps and spearfishing. Other countries are following suit,” the report says. Environmentalists in the region have taken to planting fast-growing coral species in the hope of improving the coral cover. Experts, however, feel more needs to be done.


Report: Status and Trends of Caribbean Coral Reefs (1970-2012)

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