An Analysis of Zooplankton Fauna Associated with Mangrove and Non-Mangrove Ecosystems in Mauritius

Abstract

Zooplankton are important components of marine food webs, yet very few studies exist on the mangrove plankton of Mauritius. The aim of this study was to analyze the zooplankton fauna and to assess differences between mangrove and non-mangrove ecosystems. Two mangrove ecosystems (Pointe D’Esny and Ferney) and one non-mangrove ecosystem (Bois des Amourettes) were studied for zooplankton abundance, diversity and community structure along the southeast coast of Mauritius. The study was conducted from October to December 2012 and plankton samples were collected using standard plankton nets. Zooplankton fauna of the three ecosystems were representative of the Phyla Arthropoda, Sarcomastigophora, Mollusca, Nematoda, Annelida, Chaetognatha and Ctenophora. Copepods formed the bulk of the zooplankton community (66.44% in Pointe D’Esny mangrove ecosystem and 36.43% in the nonmangrove ecosystem). Cyclopoid Oithona was the most abundant zooplankton in the two mangrove ecosystems with densities of 964 Organisms m-3 and 7760 Organisms m-3 while Foraminiferan Globigerina (329 Organisms m-3) was the most abundant organism in the non-mangrove one. Mangrove sites were found to be more diverse (Margaleff’s Diversity Index: 1.71 and 1.41) in zooplankton than non-mangrove site (Margaleff’s Diversity Index: 1.27). This study supports the view that mangrove ecosystems are a rich habitat and nursery ground.

Keywords: Zooplankton, Abundance, Diversity, Mangrove, Copepods, Cyclopoid Oithona