UNDERWATER BAHAMAS: REEF GARDENS (2) – CORALS


Purple Seafan Coral ©Melinda Riger @GBS

UNDERWATER REEF GARDENS IN THE BAHAMAS (2): CORALS

This is part 2 of a series that started out HERE with a selection of anemones, basket stars and Christmas tree worms. The images below show a wide variety of corals. In among them are also sponges and anemones. These photos are evidence of a healthy reef environment in the waters of the northern Bahamas. Abaco’s coral reef is the third largest barrier reef in the world (yes, I hear you – the Great Barrier… And the second is???), providing wonderful and accessible diving / snorkelling opportunities. However, monitoring shows that the incidence of coral bleaching and disease is increasing in the Bahamas, as elsewhere in the world.  It’s a sobering thought that your grandchildren may never swim in an environment with any of the living corals shown below…

Corals ©Melinda Riger @ G B ScubaCoral ©Melida Riger @ G B  ScubaCoral ©Melinda Riger @ G B Scuba 1Coral ©Melinda Riger @ G B Scuba 2Coral ©Melinda Riger @GBSImage Credits: ©Melinda Riger @ Grand Bahama Scuba

CARIBBEAN CORAL REEFS FACE COLLAPSE – IUCN REEF MONITORING REPORT


CARIBBEAN CORAL REEFS FACE COLLAPSE

Caribbean coral reefs are in danger of disappearing, depriving the world of one of its most beautiful and productive ecosystems

Guardian: Monday 10 September 2012 03.00 BST

• INTERACTIVE GUIDE: CORAL REEFS AROUND THE WORLD

• WHAT DOES A CORAL REEF SOUND LIKE?

coral reef

A pair of French angelfish enjoy the coral reef in the Caribbean Sea. Photograph: Marcus Mays for the Guardian

 

Caribbean coral reefs – which make up one of the world’s most colourful, vivid and productive ecosystems – are on the verge of collapse, with less than 10% of the reef area showing live coral cover.

With so little growth left, the reefs are in danger of utter devastation unless urgent action is taken, conservationists warned. They said the drastic loss was the result of severe environmental problems, including over exploitation, pollution from agricultural run-off and other sources, and climate change.

The decline of the reefs has been rapid: in the 1970s, more than 50% showed live coral cover, compared with 8% in the newly completed survey. The scientists who carried it out warned there was no sign of the rate of coral death slowing.

Coral reefs are a particularly valuable part of the marine ecosystem because they act as nurseries for younger fish, providing food sources and protection from predators until the fish have grown large enough to fend better for themselves. They are also a source of revenue from tourism and leisure.

Carl Gustaf Lundin, director of the global marine and polar programme at the International Union for Conservation of Nature (IUCN), which published the research, said: “The major causes of coral decline are well known and include overfishing, pollution, disease and bleaching caused by rising temperatures resulting from the burning of fossil fuels. Looking forward, there is an urgent need to immediately and drastically reduce all human impacts [in the area] if coral reefs and the vitally important fisheries that depend on them are to survive in the decades to come.”

Warnings over the poor state of the world’s coral reefs have become more frequent in the past decades as pollution, increasing pressure on fish stocks, and the effects of global warming on the marine environment – in the form of higher sea temperatures and slightly elevated levels of acidity in the ocean – have taken their toll.

Last year, scientists estimated that 75% of the Caribbean’s coral reefs were in danger, along with 95% of those in south-east Asia. That research, from the World Resources Institute, predicted that by 2050 virtually all of the world’s coral reefs would be in danger.

This decline is likely to have severe impacts on coastal villages, particularly in developing countries, where many people depend on the reefs for fishing and tourism. Globally, about 275 million people live within 19 miles of a reef.

IUCN, which is holding its quadrennial World Conservation Congress on Jeju island in South Korea this week, said swift action was vital. The organisation called for catch quotas to limit fishing, more marine-protected areas where fishing would be banned, and measures that would halt the run-off of fertilisers from farmland around the coast. To save reefs around the world, moves to stave off global warming would also be needed, the group said.

On a few of the more remote Caribbean reefs, the situation is less dire. In the Netherlands Antilles, Cayman Islands and a few other places, the die-off has been slower, with up to 30% coverage of live coral still remaining. The scientists noted that these reefs were in areas less exposed to human impact from fishing and pollution, as well as to natural disasters such as hurricanes.

The report – compiled by 36 scientists from 18 countries – was the work of the IUCN-coordinated Global Coral Reef Monitoring Network.

A GLIMPSE OF ARTIFICIAL REEF NIGHTLIFE – ABACO, BAHAMAS


A GLIMPSE OF ARTIFICIAL REEF NIGHTLIFE

This very short time-lapse video was posted on the always informative ABACO SCIENTIST website administered by Craig Layman of FIU (Florida International University). The site benefits from the wide knowledge of a variety of contributors in many different fields. As it says, Abaco, just like all of the Bahamian Islands, hosts a wealth of natural wonders. From parrots to whales to blue holes to mangrove wetlands, it is no wonder that scientific research is thriving on the island. The Abaco Scientist is intended as your one-stop source for all things science on Abaco and throughout The Bahamas.

The coral reefs of Abaco and the Bahamas (as elsewhere) are vital yet vulnerable eco-systems. The adverse effects of global warming (or however you describe it if you shy away from that specific term) are increasingly evident. To that damage can be added a slew of other major threats to coral survival – and to the marine life that thrives on the reefs.  There are a number of research projects in progress in the Bahamas into the effectiveness of artificial reefs as a means of conservation of the ecology of reef waters. One of these is by FIU undergraduate student Martha Zapata. In her words, We have recently been capturing time lapse video of the artificial reefs at night. Many reef fishes, like grunts, will leave the reef around dusk to forage in the nearby seagrass beds during the night. We wanted to be able to observe the fish on the reefs without influencing their behavior, so we used infrared light (which fish cannot see) to illuminate the reef. The image sequences have shown a stark difference in fish abundance from day to night. Also, we have been able to observe some of the more cryptic organisms that have made these reefs their home. Usually masters of disguise, urchins roam about the surface of the reef. Look out for the banded coral shrimp and crab that crawl up the side of the reef to graze on algae and detritus while the fish are away. Even a moray eel makes an appearance near the end!

Besides specially constructed artificial reefs, other man-made objects provide  good foundations for an artificial reefs and marine life – in particular, wrecks. There are many of these in the low waters of the Bahamas, some centuries old, others recent. Fred and Melinda Riger of Grand Bahama Scuba, Freeport, take their diving schools to wrecks because of the profusion of marine life that gathers around – and indeed inside – them.