Spatial and temporal variations in environmental variables in relation to phytoplankton composition and biomass in coral reef areas around Unguja, Zanzibar, Tanzania

Limbu and Kyewalyanga SpringerPlus (2015)4:646 DOI 10.1186/s40064-015-1439-z

Open Access

RESEARCH

Spatial and temporal variations in environmental variables in relation to phytoplankton composition and biomass in coral reef areas around Unguja, Zanzibar, Tanzania S. M. Limbu1,2* and M. S. Kyewalyanga3 *Correspondence: [email protected] 1 Department of Aquatic Sciences and Fisheries, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, Tanzania Full list of author information is available at the end of the article

Abstract  Phytoplankton can indirectly indicate health status of coral reefs due to their sensitivity to changes in water quality parameters. This study explored the spatial and temporal variability in water quality and nutrients in relation to phytoplankton community composition and chlorophyll a concentration at Bawe, Mnemba, Chumbe and Pongwe coral reef sites in Unguja Island. In situ measurements of dissolved oxygen, temperature, salinity and pH were done every month for 1 year. Surface water samples were collected for determination of phytoplankton composition, nutrients and chlorophyll a concentration. Dissolved oxygen, temperature, salinity and pH did not differ significantly among the four sites (p > 0.05) but showed significant temporal variations among months (p