Enterococci, a bacterial fecal indicator, and its correlation with coral disease abundance in Bonaire

Coral reef environments are diverse and productive ecosystems that supply a variety of benefits to marine species and humans alike. Unfortunately, these same reefs, including Bonaire’s, are under increased stress from anthropogenic activities such as nutrient and bacteria groundwater runoff. With poor sewage control, nutrients and bacteria can leech into the groundwater and flow directly into our reefs and thus increase the frequency and intensity of coral disease and bleaching. Enterococci, a common bacteria found in the intestines of humans, is used as an indicator of fecal contamination in water sources. In this study, 10-m transects and Enterococci water samples were taken at three high human impact (HHI) sites and two low human impact (LHI) sites. Although Enterococci was present in the water column at four of the sites, there was no correlation between increased Enterococci and abundance of coral disease. The Enterococci concentration levels at one site were higher than what the Environmental Protection Agency deems a healthy recreational water concentration. Coral disease was present at each site, with frequencies ranging from 12.4-19%. LHI sites had 4.2% more diseased coral than HHI sites. The direct cause of many coral diseases is unknown, although there are a variety of factors that likely contribute to their outbreak and spread. Tourism, terrestrial runoff and nutrient overload all affect coral disease abundance in Bonaire. Since coral disease was present at each site, further protection and prevention must be implemented to reduce the outbreak and spread of diseases before the coral reef is degraded past repair

This student research was retrieved from Physis: Journal of Marine Science XIV (Fall 2013)19: 41-48 from CIEE Bonaire.

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