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University of Denver

Publication Date

Fall 2014

Program Name

Tanzania-Zanzibar: Coastal Ecology and Natural Resource Management


A census as well as behavioral analysis of six grouper (Serranidae) species was conducted on Chumbe Island off the coast of Unguja, Zanzibar, Tanzania during October and November 2014. The six species were counted, divided into size classes, and behavioral notes were taken on the individuals observed on both the western drop-off of Chumbe Island’s reef as well as the back, shallower reef. Results showed that larger individuals, as well as species that grow larger, inhabit the deeper waters of the drop-off, while smaller species and juveniles inhabit the shallower back reef. The Brown Marbled (Epinephelus fuscoguttatus) and Blacksaddled (Plectropomus laevis) Groupers were determined to be two of the largest fish on the reef, and the numbers of large E. fuscoguttatus are higher than originally believed, a sign of a healthy, complex ecosystem. Biomass of all species was determined to be 9.240g/m², highly concentrated at the drop-off of the fringing reef. Juvenile percentage of each species was determined, overall suggesting a high probability of success for future generations of these species. Active hunters were determined to be Peacock (Cephalopholis argus) and Redmouth (Aethaloperca rogaa) Groupers, while E. fuscoguttatus and Slender (Anyperodon leucogrammicus) Groupers spent most of their time concealing themselves in coral. Most of the species were found to have very specific habitats on the reef, especially the large individuals.


Natural Resources and Conservation | Natural Resources Management and Policy


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