Rare Caribbean coral discovery

This video from the USA is called Coral Restoration Foundation mini-Documentary.

Navassa: Strangest island in the Caribbean may be a sanctuary for critically endangered elkhorn coral

12 Jul 2012 12:47:48 GMT

Don’t feel bad if you haven’t heard of Navassa Island, even though it’s actually part of the U.S. according to the Guano Islands Act of 1856. This uninhabited speck between Haiti and Jamaica, barely bigger than New York City’s Central Park, has a bizarre and bloody history – and may be a crucial refuge for endangered coral in the Caribbean.

Navassa has been underwhelming visitors since 1504, when crewmen sent by Columbus arrived and promptly died from drinking contaminated water. An American sea captain claimed the mesa-shaped islet for the U.S. in 1857 for its rich deposits of bird excrement, used to make fertilizer and gunpowder. Over the next three decades, African-American workers living in virtual slavery mined over a million tons of fossilized guano by hand (which the Navassa Phosphate Company of Baltimore shipped out on the S.S. Romance). In 1889, the workers rose up and killed five supervisors, sparking a legal battle over possession of the island that went all the way to the U.S. Supreme Court. The island and its animal inhabitants – mostly lizards and feral dogs today – were abandoned in 1898 after the Spanish-American War.

Haiti still claims Navassa in its constitution, but the U.S. Fish and Wildlife Service declared it a National Wildlife Refuge in 1999. Only researchers can drop anchor there today, but the interesting part is underwater anyway. This March and April, scientists with the Global Reef Expedition, a 5-year worldwide coral survey sponsored by the Khaled bin Sultan Living Oceans Foundation, made 212 data-gathering dives on Navassa’s reefs. They found a surprisingly rich coral ecosystem that has escaped much of the damage that overfishing, pollution and climate change have wrought on other reefs in the region.

While Navassa’s reefs have suffered from mass bleaching events and outbreaks of disease over the past decade, the team found virtually no evidence of either during their surveys, says Andrew Bruckner, the foundation’s chief scientist. “The overall condition of the remaining coral colonies was very good,” he says, “and there has been an increase of some types of faster-growing corals.”

There was still come cause for concern: macroalgae (seaweed), which can crowd out growing coral, was plentiful, while large colonies of living coral were still rare. Large, ecologically important fish were rare, likely due to pressure from impoverished Haitian fishermen, and the researchers saw lionfish, a voracious and quickly spreading invasive species, on almost every dive. Overall, though, Navassa’s coral cover has increased since the last survey in 2008, and many of the coral colonies that were affected by bleaching and disease have started to grow back.

The most encouraging discovery was an abundance of endangered elkhorn coral (Acropora palmata), whose populations have collapsed by as much as 98% throughout its range since 1980. The shallow-water coral typically grows in stands with treelike trunks and branches up to 6 feet long (hence the name). At Navassa, though, elkhorn has adapted to the island’s near-vertical underwater walls by growing in an unusual encrusting form that clings to cliffs and ledges.

ScienceDaily (July 12, 2012) — Coral reefs in the Indo-Pacific region, including the Great Barrier Reef, recover faster from major stresses than their Caribbean counterparts, leading marine scientists have said: here.

Parrotfishes and surgeonfishes—two iconic groups of fishes found in coral reefs—are largely doing OK, according to a recent paper co-authored by Academy curator Luiz Rocha. Assessing 179 species for extinction threats, the authors found that only three species are threatened globally (due to fishing pressure). However, many species are threatened locally—for example, in the Philippines and Indonesia. Read the paper in PLoS ONE here. See also here.

Since the early 90s the rapid spread of the invasive, Indo-Pacific Lionfish (Pterois volitans/miles) throughout the Caribbean region has been an increasing problem for marine park managers and conservationists. On a number of Caribbean islands, lionfish control programmes were set in motion, often with a volunteer control component. On Bonaire, such a programme was initiated immediately after the first lionfish was spotted on both islands in 2009. On Curaçao, a control programme was adopted two years later: here.