New Evidence Highlights Threat to Caribbean Coral Reef Growth: Many Caribbean Coral Reefs Are Starting to Erode

ScienceDaily. Jan. 29, 2013 — Coral reefs build their structures by both producing and accumulating calcium carbonate, and this is essential for the maintenance and continued vertical growth capacity of reefs. An international research team has discovered that 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.

Coral reefs form some of the planet's most biologically diverse ecosystems, and provide valuable services to humans and wildlife. However, their ability to maintain their structures and continue to grow depends on the balance between the addition of new carbonate, which 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. But the paper, published on DATE TBC in Nature Communications, is the first evidence that these ecological changes are now also impacting on the growth potential of reefs themselves. Read more

View the original article here

A Glimmer of Hope for Coral Reefs

by Dennis Normile on 7 January 2013, 3:10 PM. Science Now

Climate change is expected to devastate coral reefs, as warmer oceans are believed to be inhospitable to corals. But corals may be more robust than commonly thought. A number of studies have found coral colonies that endure high water temperatures. Now, a team of scientists has taken a step toward identifying the genetic mechanisms that might be giving some corals a natural resilience to thermal stress.

Coral reef ecologist Daniel Barshis and colleagues at Stanford University in Palo Alto, California, took advantage of markedly different environmental conditions in two nearby but separate pools on a reef at Ofu Island, American Samoa. Because of local factors that isolate some areas of the reef from winds and waves that might mitigate temperature extremes, some pools in the reef are highly variable in temperature, with summertime water temperatures topping 34°C, which, depending on other factors, can trigger bleaching, or a damaging loss of the symbiotic algae that corals depend on. Yet Acropora hyacinthus, a common reef-building coral found in these pools, grows faster and is more thermally tolerant than corals of the same species in nearby pools that do not get as hot. The team took samples of corals from both the highly variable and the moderately variable pools and subjected them to thermal stress experiments under laboratory conditions while monitoring the levels of expression, or activity, of a wide range of genes.

Read more at http://news.sciencemag.org/sciencenow/2013/01/a-glimmer-of-hope-for-coral-reef.html

View the original article here

It’s Not Too Late for Coral Reefs, Experts Say

ScienceDaily (Oct. 3, 2012) — Coral reefs — ecosystems of incredible environmental and economic value — are showing evidence of significant degradation, but do not have to be doomed. We can make a difference.

From Left to Right: back row – Richard E. Dodge, Ph.D.; dean of Nova Southeastern University’s Oceanographic Center and executive director of NSU’s National Coral Reef Institute; Former U.S. Vice President Al Gore; and NSU President George L. Hanbury II, Ph.D.. Front row – NSU Oceanographic Center graduate students demonstrate how NSU’s onshore coral reef nurseries work (Credit: Nova Southeastern University)

Once plentiful, coral reefs worldwide and locally have been ravaged by a number of stresses, including global threats like rising sea temperatures and ocean acidification, and local threats like pollution, overfishing and coastal development. An estimated 25-30 percent of the world’s coral reefs are already severely degraded or lost, and another very high percentage are in danger of greater impact or worse. Some even predict reefs could be essentially wiped out within a human generation unless action is taken.

The coral reef issue is not only an environmental problem, but an economic one. The United Nations estimates globally, coral reefs generate over $172 billion per year from the services they provide including tourism, recreation and fisheries. In South Florida alone, where 84 percent of the nation’s reefs are located, reef ecosystems have been shown to generate over $6 billion in annual economic contributions and more than 71,000 jobs.

In July, hundreds of scientists joined in a consensus statement written at the recently held 12th International Coral Reef Symposium in Cairns Australia, stating: “Across the globe, these problems cause a loss of reef resources of enormous economic and cultural value. A concerted effort to preserve reefs for the future demands action at global levels, but also will benefit hugely from continued local protection.”

Read more

View the original article here