A Glimmer of Hope for Coral Reefs
Author: Dennis Normile
January 7, 2013
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.
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