More bad news for regional reefs

(CNS): Reefs in the Caribbean region have stopped growing or are already beginning to erode, according to new research. The amount of new carbonate being added by Caribbean coral reefs is now significantly below rates measured over recent geological timescales, and in some habitats is as much as 70% lower. This latest news comes at a time when the Cayman community is still arguing about the Department of Environment’s advice to expand our existing marine parks in an effort to try and save the reefs in our area. The scientists warn that unless greater care is taken of local reefs they will deteriorate considerably, impacting both tourism and fishing.

The research was undertaken by reef experts at the University of Queensland (UQ) in Australia and University of Exeter in the UK. The marine scientists explained that coral reefs build their structures by both producing and accumulating calcium carbonate but found a significant decline in our region. Professor Peter Mumby from UQ's School of Biological Science said this could affect millions of people who benefit from reef structures.

"Reef structures provide benefits such as being fishery habitats for seafood, they are used for recreational diving adventures, and often provide a natural barrier to storm surge," Professor Mumby said. "Our new findings imply that the benefits people receive from reefs will deteriorate considerably unless we take greater care of them.”

Coral reefs form some of the planet's most biologically diverse ecosystems, and provide valuable services to humans and wildlife. Their ability to maintain their structures and continue to grow depends on the balance between the addition of new carbonate.

This is mostly produced by corals themselves, set against the loss of carbonate through various erosional processes. Scientists have long known that reef ecosystems are in decline and that the amount of live coral on reefs is dwindling.

This research was published in Nature Communications and is the first evidence that these ecological changes are now also impacting on the growth potential of reefs themselves.

Professor Chris Perry said estimates of current rates of reef growth in the Caribbean are extremely alarming.

“Our study goes beyond only examining how much coral there is, to also look at the delicate balance of biological factors which determine whether coral reefs will continue to grow or will erode," Perry said.  "Our findings clearly show that recent ecological declines are now suppressing the growth potential of reefs in the region, and that this will have major implications for their ability to respond positively to future sea level rises. It is most concerning that many coral reefs across the Caribbean have seemingly lost their capacity to produce enough carbonate to continue growing vertically, whilst others are already at a threshold where they may start to erode.”

He added that urgent action to improve management of reef habitats is critical to reduce further deterioration of reef habitat.

However, here in Cayman the consultation is on-going and the environment minister continues to drag his feet over the need to expand marine parks as a result of complaints from some fishermen about the proposals from the DoE. The planned expansion of the parks drawn up by the DoE was based on scientific evidence and extensive research in the face of the pressing need to try and preserve Cayman’s own reefs and marine habitat.

While the reefs around the Cayman Islands are some of the best in the region because of action taken to create protected areas some 25 years ago, the reefs face increasing threats from a variety of climate related problems as well as fishing pressures.

If the parks are not expanded the preservation work of the last 25 years could be seriously undermined and Cayman’s reefs could begin to deteriorate as badly as others in the region, reducing their potential for fishing and attraction to divers.