In an earlier blog post we talked about how important Parrotfish are to the health of the coral reef. Another great article discussing the health of coral reefs in relationship to the Parrotfish has just come out in the NY Times. It outlines various studies of reefs in the Caribbean and elsewhere and how this is dependent on algae grazing fish, primarily Parrotfish populations, to keep algae overgrowth under control. As reefs diminish due to warming waters, pollution, and overfishing, algae growths tend to develop on the dead coral and can completely take over a reef, including the healthy, live coral struggling to survive. It is only due to algae-eating fish that this growth can be contained, giving corals time and space to recover and grow back. Thus the issues of over-fishing affect the viability of coral reefs under duress.
Out at Glover’s Reef we see this effect firsthand. The atoll is a marine reserve but is divided into two sections: one is a no-fishing, protected zone and the other is a limited fishing area. The concept is that the protected zone will allow marine life to reproduce and spread into the harvest zone, providing a steady supply of fish to catch. However, the fishing zone is over-fished on a regular basis, and as a result the coral reefs in that zone are very unhealthy with far fewer areas of live coral, and much more algae growth, than those found in the protected zone. Lucky for us, all of the coral patches within swimming and kayaking distance are in the protected zone.