Belize Expedition, 2011
From Jay Dimond:
One of our primary tasks on this trip is to begin a long-term monitoring project on the local barrier reef system. This monitoring project is designed to ask a fairly simple question: How do coral reefs change over time?
Caribbean coral reefs have changed considerably over the past few decades. Elkhorn and staghorn corals were once among the dominant reef corals in the Caribbean, but now they are rare. A series of events brought on their demise, starting with an increase in coral diseases and some severe hurricanes in the early 1980s. Subsequently, herbivore populations (primarily sea urchins and fish) were reduced by overfishing and disease, which allowed fast-growing algae to overgrow areas that were once dominated by coral. Today, many Caribbean reefs are still covered in algae, and the pace of coral recovery is very slow. [Read more about coral recovery in different parts of the world in this post by Dr. Randi Rotjan about the Phoenix Islands and in this post from Fiji by Dr. Steve Webster ]
Has this sort of scenario happened before? The fossil record suggests that it has not. Cores from Belizean reefs not far from here on Carrie Bow have shown that this recent loss of elkhorn and staghorn coral was unprecedented for at least 3000 years. The cores showed a nearly continuous record of staghorn coral, until it was replaced by algae or lettuce coral within the past thirty years.
Acropora cervicornis staghorn (L) and Acropora palmata elkhorn (R) corals in Belize. (Photo: J. Dimond)
On this and in the previous four trips I have made to Carrie Bow, I am constantly reminded of the past, etched in the rubble of corals that once lived and left behind their stony framework. Meanwhile, small juvenile corals growing among this rubble are harbingers of the future potential of the reef. We can only hope that our new monitoring program will document coral recovery rather than decline.