This from New Scientist highlights a fascinating finding about coral:
When the temperature soars, coral reefs might cool off by creating their own clouds.
Research from the Great Barrier Reef off the Australian coast shows that corals are packed full of the chemical dimethyl sulphide, or DMS. When released into the atmosphere, DMS helps clouds to form, which could have a large impact on the local climate.
In the air, DMS is transformed into an aerosol of tiny particles on which water vapour can condense to form clouds. This sulphur compound is also produced in large amounts by marine algae and gives the ocean its distinctive smell. Algae play a vital part in regulating Earth’s climate, but no one had looked at whether coral reefs might have a similar role.
Graham Jones of the Southern Cross University in Lismore, Australia, and colleagues measured DMS concentrations in corals in the Great Barrier Reef and its surrounding water. They found that the mucus exuded by the coral contained the highest concentrations of DMS so far recorded from any organism. A layer rich in DMS formed at the sea surface above the reef, where it was picked up by the wind.
“Although globally the emission of DMS from the Great Barrier Reef is not huge, on a regional basis it is very significant,” says Jones.
It’s certainly true that corals under stress produce a thicker mucous coat than they do normally, and the same applies to other reef-dwelling cnidarians such as anemones. It’s off that nobody noticed this before, because it’s common knowledge to home reef-keepers.
Incidentally, the coral reef came about historically during the Cambrian period, and it’s one of the most diverse ecosystems on the planet. Next time you find a creationist carrying on about the impossibility of the Cambrian Explosion you can point to two Cambrian things that lead to a big take-off in evolution: sexual reproduction and the coral reef.