12 October 2008

Revitalizing Florida's coral reefs: nurseries and finding tough strains

New approaches to help damaged reefs recover and survive climate change include setting up coral nurseries and finding resilient strains of hard corals.

Although corals grow so slowly that "it's like watching paint dry,", coral nurseries are considered cheap, as ecological experiments go, so it's very cost-effective and "very promising."

There will also be efforts to mitigate damage to reefs. Florida already has a reef-resilience program that closely monitors bleaching events. Also considered are restrictions for zones with largest corals and largest number of coral colonies, such as improving law-enforcement protection, and keeping lobster and crab traps away.

Singapore has also started a coral nursery at Pulau Semakau, although the area near the nursery is also used to park oil rigs being serviced, and for a fish farm.

Researchers work to revitalize Florida's coral reefs
Ludmilla Lelis, Orlando Sentinel 12 Oct 08;
Scientists trying to save Florida's diminishing coral reefs are using new approaches to help damaged reefs recover and survive a changing climate.

Damage from environmental problems, including climate change, is inevitable, they say, so they focus their work on what they can do. Through resiliency research, they hope to find the reasons some corals can overcome problems, and which are the more hearty corals that should be protected. Other scientists are preparing for the restoration of damaged reefs by growing the corals to replace them.

The two approaches could help in the battle to save corals that are being ravaged by pollution, ships, tropical storms and bleaching -- a phenomenon that leaves corals colorless and lifeless.

Nurseries for recovery

Two South Florida projects are growing future reefs in nurseries in Biscayne National Park. Coral nurseries are growing pieces of coral, which would be transplanted to damaged or dying reefs elsewhere.

Growing coral had been a hobby for the aquarium trade, but it has become a crucial scientific project, said James Herlan, a graduate student at the University of Miami's Rosenstiel School of Marine and Atmospheric Science. At the school's nursery in the national park, he glues fragments of staghorn coral onto cement platforms with a nontoxic epoxy.

"Coral nurseries in the Caribbean are a newer idea, but there is now more of an urgency to do this," Herlan said.

The underwater nursery has survived through trial and error. The corals are sprouting their distinctive hornlike shapes at a rate of 6 inches a year, just as fast as they would in the wild.

"It's cheap, as ecological experiments go, so it's very cost-effective," Herlan said. "It's very promising."

Biscayne National Park also runs a coral nursery, under a dock at Adams Key, using slow-growing boulder coral. Richard Curry, the park's ocean, reef and science manager, had rescued pieces from ship groundings and other accidents. He has made it a community project, using volunteers to epoxy the pieces to PVC pipes, laid in neat rows under the dock.

"It's like watching paint dry," Curry said of how slowly the corals grow. But he thinks it's good insurance for the future.

"We're not at the crisis yet where we need to have something like a 'captive breeding' program," he said. "But we will someday, and hopefully we'll be ready for that."

Finding resilient strains

Other scientists have focused on making reefs more resilient.

Pollution and the summer doldrums -- long stretches of tropical heat -- can spark a massive bleaching. Coral, responding to the stress, expels the colorful algae that normally live inside it, leaving the coral a white, lifeless skeleton. But some coral colonies can survive and grow back more quickly than others.

Researchers want to know why some reefs rebound, hoping to use that knowledge to better protect the hardier patches of reef.

Florida already has a reef-resilience program that closely monitors reef zones when bleaching happens.

No South Florida zones are immune to bleaching, according to a recent study. However, some zones with the largest corals and the largest number of coral colonies need to have more restrictions that protect them from damage. For example, a reef-resilience conference in Key Largo earlier this year came up with 129 strategies that could help the reefs better survive, such as improving law-enforcement protection of sensitive areas, and keeping lobster and crab traps away from living reefs. State officials already plan to end one environmental problem. Outfalls, pouring treated sewage into the ocean, will be shut down by 2018.

However, the greatest test of resiliency is whether coral reefs can withstand rising sea temperatures.

University of Miami Assistant Professor Andrew Baker has found that some corals appear to be more heat tolerant than others. The advantage apparently depends on microscopic algae living inside the corals. Some algae are more heat-tolerant. The corals that persisted after bleaching tend to have more of those heat-resistant algae.

With a $150,000 Pew Fellowship, Baker will spend the next three years trying to find ways to boost that natural heat tolerance, including injecting those algae inside the coral's limestone skeletons.

"We're faced with an unfortunate inevitability that global warming is here to stay even if we can bring down our emissions, so we need to do everything we can to save as many corals as we have left," he said.

Gradually, he will take his laboratory findings to larger reefs in South Florida and hopes to team up with coral nurseries to make sure that corals being grown will be better able to withstand global warming.

"This is not going to save the world's coral, but we may be able to find techniques that we can offer in a package of solutions for reef managers," Baker said.

"A failure to act guarantees the corals will be lost."

No comments:

Post a Comment


Related Posts with Thumbnails