Friday, May 6, 2011

Belize Expedition: Time heals all wounds?

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.



  1. These reports are great! I've just finished an amateur diving trip to the reefs on the West side of St. Croix and found it difficult to determine the health of the reefs. Can you all give some quick tips? What would be the 4-5 things one might look for to make a quick guess about whether a reef is healthy?

  2. Jay,

    We own Long Caye at Glover's Reef in Belize and have see with our own eyes what you are talking about. We found that the elkhorn and staghorn corals changed dramatically in the summer of 1998. This very hot summer ended in Hurricane Mitch, one of the top largest hurricanes to date. The heat of the ocean not only brought on this massive hurricane, it also appeared to cause coral bleaching, which killed a lot of the shallow corals, which gave the algae the niche they were looking for. Since Mitch we have watched the elkhorn and staghorn come back slowly, but it is still nothing like it was prior to 1998.

    Lucy Wallingford