Etude de faisabilité technique et socio-économique de l’algue rouge Halymenia durvillei ( Bory de Saint-Vincent, 1828) dans le Sud-Ouest de Madagascar i

Abstract

A study on the technical and socio-economic feasibility of the red alga Halymenia durvillei was
conducted in the southwest of Madagascar between July 2021 and January 2022. This study
aims to diversify the species subject to aquaculture in Madagascar. Three (03) parameters were
highlighted such as the ideal weight of the cuttings, the optimal cycle of the culture and the
adequate depth for the installation of the culture lines. The technique adopted was the long line.
For this, five (05) lines of 20 m composed of 500 young cuttings were used. It emerges from
this study that the ideal weight of the cuttings to start the culture is between 70 g to 130 g and
the optimal cycle is between 30 and 60 days. The lines of culture are always to be installed at 1
m of surface of the sea water, but can be located at 1 m of the bottom during the climatic hazards
(cyclone or high temperatures). On the socio-economic level, the culture of the species is
feasible by offering an annual income of 7 200 000 Ar per farmer. Further research should be
done to know the performance and production capacity of this new species.