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1 .<-NARRATOR:->Listen to part of a lecture in a marine biology class.
1 .<-FEMALE PROFESSOR:->So, we've been fairly thorough in our discussion about coral reefs-which of course are prominent oceanic features made of hard, limestone skeletons produced by tiny coral animals.
2 .We've gone over where coral reefs are usually formed-along the edges of shallow ocean banks in tropical or subtropical regions.
3 .And the fact that they're declining at an alarming rate. But, I don't want to leave you with the impression that all is lost....
4 .There are several techniques being employed today that could prove useful in assuring the future of the reefs.
1 .Now, we've talked in depth about coral bleaching, or whitening, which, as you'll recall, is a symptom of, well, that the coral is suffering.
2 .As you know, coral is very sensitive to water temperature...
3 .Even a one-or two-degree Celsius rise in sea surface temperature for a relatively short amount of time can cause bleaching.
4 .Recently researchers have used data collected by monitoring surface water temperatures to improve the ability of a reef to recover from bleaching.
5 .One future possibility is that improved monitoring can help predict where and when bleaching will occur, ... which might potentially enable us to mitigate its effects.
1 .And, there's another technique that's being experimented with to try to help coral reefs recover from bleaching... It's called coral transplantation.
2 .This involves moving young coral from a healthy reef onto a degraded reef... you know, in an attempt to regenerate the degraded reef by encouraging young, healthy coral to take over.
3 .There has been some success with this, but it's still somewhat controversial.
4 .Some scientists support it because, well, for one thing, it means you don't have to rely on the existing coral to reestablish itself... because it might not be able to.
5 .But in my opinion, transplanting coral should only be used as, well, as a last resort.
6 .I mean, this method is not only costly, but it's... well, even if it's successful, it still fails to address the ongoing problem-the root causes of the degradation, which really is paramount to devising an effective solution.
7 .So I don't really take comfort in the successes that they've had with transplantation.
1 .Perhaps a more constructive use of our time could be spent researching corals that do survive-like in areas known as refugia.
1 .Refugia are areas on the reef that are seemingly, well, resistant to bleaching.
2 .See, when coral reefs experience bleaching... uh, it-it's rarely a case of the whole reef being affected.
3 .There're almost always pockets of coral on the reefs that remain unaffected... and these are often the lower areas of the reef... those located in deeper water, where temperatures are lower.
4 .Now, we have evidence that corals in these locations are able to escape the destructive bleaching that affects portions of the reef in shallower, warmer water.
5 .So in my mind, it's these refugia that are the key components of overall reef resilience...
6 .These should be the area of concentration for researchers... to locate and protect those regions as a way to sustain coral reefs.
1 .And we can also protect reefs by protecting the surrounding ecosystems, like mangrove forests and sea grass beds.
2 .Both of these grow in coastal waters, often in the vicinity of coral reefs.
3 .By protecting these areas, we also protect the coral.
4 .Let's take, for example, the mangrove forests...
5 .Mangrove root systems have the ability to absorb and, well, trap sediments and pollutants in water that flows through them before they enter the ocean.
6 .This of course has beneficial results for the nearby coral reefs.
1 .And fisheries management is another key strategy.
2 .Over fishing can be seriously disruptive to coral.
3 .Let me give you a couple of examples.
4 .Over fishing certain species of fish and shellfish like snappers, barracudas, and even lobsters... well, all of these creatures feed on snails, worms, and other organisms that eat coral-so depleting the number of lobsters, for example, means that we're adding to the threat of coral decline.
5 .Sea urchins are another example.
6 .They eat algae and prevent it from overwhelming the coral.
7 .Since the disappearance of sea urchins from the waters off the coast of south Florida, many coral reefs there have been smothered by the uncontrolled growth of algae.