Estuarine lakes: linkages and lineages across longitudes in the Western Indian Ocean

Abstract

Recent observations (1) of purported South African endemic species from south east Madagascar prompted the “Suitcase” programme, supported by the African Coelacanth Ecosystem Programme (ACEP), to investigate regional genetic connectivity of fauna from various coastal marine habitats. Work presented here focusses on estuarine fauna (invertebrates and fishes). There are strong morphological and habitat similarities in estuarine lakes in SE Madagascar (Vinanibe and Mananivo) and NE South Africa (Kosi). Local people use these systems in similar ways in both countries, deriving similar ecosystem benefits. However, no physicochemical or biological surveys have been conducted of estuarine lakes in SE Madagascar, and no comparative ecological assessment has been made between systems across the island state and mainland Africa. Typically, coastal lakes are inhabited by relatively short lived species with high life cycle dependence on estuaries and genetic connectivity across longitude (the Mozambique Channel) could be expected to be minimal in these systems.