Dr. James Crabbe Studies Link Between Sea Temperatures and Coral Growth

In his recently published paper, biochemistry professor James Crabbe (University of Bedfordshire) explores how rates of sea surface temperature (SST) change influence the growth of coral colonies, with his research focusing on the growth of the branching coral Acropora palmata.

Crabbe has done research in Jamaica and Belize on coral recovery and bleaching, with Earthwatch support, since 2002. Each year, Earthwatch volunteers don scuba gear and set out to take measurements of the coral reefs surrounding Jamaica. In 2007, Crabbe also started collecting coral reef growth data by using an ROV (remotely operated vehicle).

As Crabbe notes in his paper, there is no question that there is a link between sea surface temperature and coral growth and recovery. Researchers have been trying to quantify that relationship for some time. Accurate growth modeling will help us understand the effects that climate change and other anthropogenic have on coral growth. Knowing this, we can then manage coral reef systems more effectively, and maximize their sustainable use.

This is important because coral reefs provide an environment for more than one third of all marine fish species, and are the source of 6 million tons of fish caught annually. With sea surface temperatures increasing, these centers of ocean biodiversity and biomass are at risk.

Crabbe reports two separate findings in his paper:

  • There was no significant difference between measurements on the same colonies made from photographs using scuba divers and photographs captured from video using Crabbe's ROV.
  • For this particular species of coral, a rational polynomial function provides a more accurate model for growth than a logarithmic function.

For Crabbe, this means that he can employ his ROV in measuring coral growth in places too deep or unsafe for people to scuba dive, with confidence that the results will be accurate. And, that researchers are closing in on determining just what the relationship is between SST and coral growth.

Earthwatch is proud to have provided support to Prof. Crabbe's research. Support for research like this is a critical part of our mission. In the next ten years, Earthwatch will be expanding our portfolio of climate change research projects.


For more information on the adventures of PI James Crabbe, read "The Spy Who ROVed Me" in the January issue of The Expeditioner.

Crabbe's paper appears in Computational Biology and Chemistry 31 (2007) 294-297.

Dr. Crabbe on boat

Taking measurements