UM biologist works to help reefs survive global warming

THE ENVIRONMENT

UM biologist works to help reefs survive global warming
A UM scientist who hopes to develop a natural heat shield for sensitive corals facing rising ocean temperatures has won what was described as the `Nobel Prize for marine conservation.'

Posted on Tue, Feb. 05, 2008
BY CURTIS MORGAN
cmorgan@MiamiHerald.com

Andrew Baker of UM's Rosenstiel School of Marine and Atmospheric Science holds a specimen of Elkhorn coral.


For the better part of a decade, Andrew Baker has charted how
rising ocean temperatures have ravaged reefs from the Florida Keys to Australia, triggering outbreaks of ''bleaching'' that drain corals of vibrant color and, frequently, life.
Now, the University of Miami marine biologist is going to try to give corals a better shot at surviving a changing climate likely to put them in even hotter water in the future.
Baker won a prestigious Pew Fellowship in Marine Conservation on Tuesday for a three-year project aimed at developing ways to essentially inoculate temperature-sensitive corals against the expanding impact of global warming.
''Reefs are under siege from many threats, but climate change is among the most serious risks,'' said Ellen Pikitch, executive director of the Pew Institute for Ocean Science, which awarded $150,000 fellowships to Baker and recipients in China, France, Australia and Canada. ``Dr. Baker's work gives us hope that the oldest and largest corals might be saved.''
All coral need algae to survive. Baker's idea is to deliver a dose of specific heat-hardy strains of algae he first identified in pioneering genetic studies published in the science journal Nature in 2001.
LARGEST CORALS
While Baker's program likely won't leave the lab at UM's Rosenstiel School of Marine and Atmospheric Science for a year or more, he hopes to devise techniques to specifically protect the largest corals, which he called ''big mamas'' because of their age, size and key roles in coral reproduction and maintaining reef structures.
''It wouldn't be applicable to saving the world's reefs. It's a start to certainly helping,'' said Baker, an assistant professor. ``When you look at a coral the size of your desk, if you lose that coral it's going to take several hundred years to replace it.''
Healthy corals depend on a symbiotic relationship between polyps, the living tissues that slowly build the hard outer skeletons that give species distinctive shapes, and algae called zooxanthellae, which provide energy for the process. But when ocean temperatures rise too much for too long, coral shed the algae, Baker said, ``spewing them out like a stream of mucus.''
RAINBOW HUES
Because algae supply most of the rainbow hues of a reef, affected corals begin to dull and can turn a bleached bone-white. It doesn't immediately kill coral but can weaken it, slowing growth and leaving fragile reefs -- home to millions of fish, crabs and other animals -- more vulnerable to assorted diseases, pollution and damage from boaters and divers.
But some corals always do better than others. Baker believes he knows why.
Drawing on more than 12,000 samples of coral tissues from 20 countries, which he preserves in extreme 176-degree-below-zero deep freeze, Baker's earlier studies isolated specific algae as a thermal shield of sorts. They also showed that some corals adapted to warm water, using more tolerant algae after bleachings.
Just like plants in gardens or rain forests, some algae do better in shade or sun, hot or cold, Baker said, and coral can pair up with many different types at once.
The idea will be tested in UM aquariums before any work is done in the wild, which most likely would start on Keys reefs or with researchers already growing fragments in coral nurseries for use in reef restoration. First, Baker has to figure out a practical way to deliver the dose of algae to coral.
He's looking at painstaking injections in the mouths of tiny polyps, or encasing coral branches in bags full of an algae-rich brine. ''The question is, if we feed them a diet [of a specific algae], will they pick it up?'' he said.
Baker acknowledges the idea of saving whole reefs ``is a pretty tall order. Even if we can develop the techniques, the scale of the problem is so huge.''
GAUGE OF WARMING
For marine scientists, Baker said, coral bleaching events are as good a gauge of global warming as melting glaciers and thawing Arctic permafrost. Bleaching hit the Keys twice in the 1990s, preceding a die-off that claimed 30 percent of the reef tract. Bleaching also struck the Indian Ocean in 1998, Australia's Great Barrier Reef in 2002 and the Caribbean in 2005. And as oceans absorb more carbon dioxide, acidity levels increase, further weakening reef skeletons.
''It's definitely an ambitious project and it's also controversial,'' said Baker, a native of England who earned his doctorate from UM in 1999. ``There are several coral reef biologists who will say it's not going to work, that we have gotten past the tipping he point. It's time for us to try to do something with our scientific research.''
The fellowship is a first for a Rosenstiel scientist where the Pew Institute is also based. Pikitch, who said she did not take part in the decision because of potential conflict, said it was Baker's pioneering proposal that merited an honor she likened to ``the Nobel Prize for marine conservation.''
Pikitch acknowledged the work was ''high risk,'' meaning it may not work, but said more scientists must begin focusing on curing the ocean's ills.
''Rathering than simply documenting the decline and writing obituaries for reefs,'' she said, ``he's looking at innovative solutions to try to make it not come true.''

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