Reef monitoring in Maldives and Zanzibar: low-tech and high-tech science

In both countries, the most likely source of stress is sewage. Low-tech monitoring methods include community descriptions and coral growth rate determinations. Affected sites in both countries had lower coral cover and diversity, higher numbers of associates, and higher growth rates. Fish communities were very different, in Zanzibar, between stressed and unstressed reefs. High-tech methods also detected reef stress through sewage. Heavy metal values were low. Analysis of coral tissue via HPLC at Maldives showed differences in stressed sites. Stable nitrogen isotope ratios are often elevated in areas of high sewage stress. -from Authors