Corals Need Sunscreen Too?

As a fair-skinned resident of San Pedro, I've become very used to waking up each morning and applying sunscreen before I leave to go out as the sun here in the tropics is much stronger than where I grew up in the States. I was interested to learn that humans aren't the only ones that need to protect themselves against the strong rays of the tropical sun.

The corals that have built the Belize Barrier Reef are invertebrate animals that have a symbiotic relationship with algae that live in the tissues of the coral polyps. Corals that live in shallow-water are typically exposed to high levels of potentially damaging solar radiation. In addition to this potential damage from the sun, the coral's situation is made even more difficult by the release of oxygen that is produced by the algal symbionts during photosynthesis. This oxygen, when combined with high light intensities can cause toxic conditions and stress to the organisms.

Even with these potentially damaging scenarios, coral animals are able to withstand long-term exposure to damaging amounts of ultraviolet radiation from the sun. So how do the corals prevent damage from occurring? Scientists investigating how coral reefs cope with environmental stresses have isolated a compound that they believe acts as a type of sunscreen for these organisms. These compounds, known as mycosporine-like amino acids (MMAs), have the ability to efficiently absorb UV light. Corals are either able to accumulate enough MMAs, either through producing them or accumulating them through feeding, to protect themselves against the strong solar radiation that is typical of tropical areas. Researchers are even investigating the possibility that these MMAs may be able to be produced to provide another type of sunscreen for humans.

Reef Brief is a weekly column published in the San Pedro Sun

For more information on Green Reef please contact us at (email: [email protected] or telephone us at 226-2833.

Back to Reef Briefs Main page