The benthos and ichthyofauna of Baixo São João, Ponta do Ouro Partial Marine Reserve, southern Mozambique

Abstract

A preliminary reef survey was conducted in July 2015 at Baixo São João, southern Mozambique, to investigate the merits of protecting it within a sanctuary. This involved point intercept analysis of photo-quadrat transects recorded in the northern, central and southern parts of the reef, on the reef top and its inshore and offshore slopes. Visual techniques were used to superficially describe the ichthyofauna. The coral community proved to be relatively rich and uniform within all reef zones, but with no unique or over-vulnerable species. Hard corals were predominant (mean cover = 32.3%), followed by soft corals (mean cover = 12.8%). Little coral damage was evident. A total of 97 species of reef fish, belonging to 30 families was recorded. Large specimens were common, including species of commercial importance, as well as top predators. The reef would warrant protection based on the following premises: i) it is remote, rendering human interference unlikely; ii) it is located offshore in deeper water, protecting it from many of the potential effects of climate change; iii) it could provide a coral breeding refuge for replenishment of more southern reefs; and iv) it would provide a useful reference site for baseline and comparative studies.