etude de la repartition des laisses de mer et des macrofaunes benthiques de plage de la batterie, d’ifaty et de mangily ; littoral sud-ouest de madagascar

Abstract

The distribution of benthic macrofauna and lets of sea from the Toliara beach (southwest of Madagascar) was studied from samples collected between two seasons (warm seasons
and cold seasons). An inventory of the benthic macrofauna of the beach was made and the
results of the study of the spatio-temporal variation of diversity, abundances, constancy and
fidelity were presented. The zoological groups present in the three study sites are crustaceans,
polychaetes, molluscs, cnidarians and insects, with a clear predominance of crustaceans and
molluscs. The abundance estimation study showed that the averages between the stations
surveyed in the three sites studied did not significantly differ. This situation indicates that the
sites studied are very close in ecological factors and faunal population. The rate of recovery of
the benthic forms of the range of the Battery is equal to 90.11% of the sands and 9.89% of the
sea leashes; that of Mangily 72.13% of the sands, 14.44% of the rocks and 9.89% of the lets of
sea and finally of Ifaty 67.76% of the sands, 19.63% of the rocks and 12.61% of the let of sea.
The quantity of 6.98 tonnes/ hectare/ year of sea letting is estimated on the beaches studied in
the vicinity. They consist of 5 t / ha/ year of organic matter and 1.98 t /ha/year of non-organic
waste.