Gainesville, US: In the last 30 years, more than 90 percent of the reef-building coral responsible for maintaining major marine habitats and providing a natural barrier against hurricanes in the Caribbean has disappeared because of a disease of unknown origin. Now a University of Florida geographer and his colleagues applied GIS to examine human illness to show where clusters of diseased coral exist. Their findings, published in the journal PLoS One.
“What you’ll find is that spatial techniques have been used relatively little in the coral research community,” said paper co-author Jason Blackburn, a UF professor of geography and member of UF’s Emerging Pathogens Institute. “With these methods, we gain a better understanding of the disease’s distribution across the reef.”
Microbiologists and toxicologists often run laboratory tests on small samples of Acropora species of coral to determine the factors that contribute to white-band disease, known as WBD. It’s visually identified as a white band moving from the base of the coral up, killing the coral tissue as it goes, leaving only the exposed coral skeleton behind.
The researcher used data gathered in 2004 from scientists stationed at Buck Island National Monument in the U.S. Virgin Islands. Rather than determining only whether coral was affected by WBD, samplers at the station counted the individual number of healthy and non-healthy coral colonies. University researchers were then able to use this information in the Disease Mapping and Analysis Program, known as DMAP. The free software, designed by the University of Iowa initially to study Sudden-Infant Death Syndrome, was used to create maps of WBD prevalence and to locate areas with significant disease clustering.
“While the focus of our study was on a specific white-band disease outbreak, our methods could be used to determine if there’s a spatial component to just about any type of situation that might be present in an underlying population,” said Jennifer Lentz, a Louisiana State University graduate student who is lead author on the paper.
“For example, you could use these same techniques to determine whether people with cancer are clustered in a given geographical area, and if so is there something about those locations that might be contributing to the increased prevalence of cancer.”
The researchers determined that 3 percent of the Acropora coral around Buck Island had WBD. They also found the locations of significant disease clusters, information scientists can then use to narrow where they should take samples for further laboratory tests. This is the first of several studies established by the researchers exploring which types of spatial analysis are the most appropriate for various types of coral data from the Caribbean.
Source: University of Florida