Inventory and Spatial Assemblage Study of Reef Fish in the Area of Andavadoaka, South-West Madagascar (Western Indian Ocean)

Abstract

This study represents the first qualitative census of the reef fish assemblage of coral
reefs in the vicinity of Andavadoaka, south-west Madagascar. Observational data of fish species
sightings were collected over the course of a year, while visual census data, with low observer
bias, detailing fish assemblage from the four major reef zones of the area were collected in a
shorter 5-week period. A total of three hundred and thirty four (334) species from 58 families were
recorded throughout the year, while one hundred and eighty seven (187) species were observed
during the shorter assemblage study. The trophic habits of the fish population are comparable
with other sites in the Western Indian Ocean, and suggest a healthy fish community, despite
evidence of broad-scale damage from coral bleaching and associated mortality. The authors
suggest that this can be explained by current relatively low levels of anthropogenic impacts from
fishing. However, given the extent of regional reef degradation, fish species diversity may now
be particularly vulnerable to future anthropogenic or climatic disturbances, such as increased
fishing effort or renewed coral bleaching episodes.