The Mauritian Seaweed Flora Diversity and Potential for Sustainable Utilisation

The world seaweed industry is currently worth over US$7.4 billion, and the potential for increased seaweed use exists in many countries. The species diversity of seaweeds in Mauritius has been extremely well documented in comparison with many local islands and regions, largely due to the work of the Danish phycologist Dr F. Boergesen, published from 1940-1957. The recorded seaweed flora is currently 435 species (59 brown algae, 108 green algae and 268 red algae), which is more than have thus far been recorded in either Kenya or Tanzania, and many more than for any other similar islands in the Indian Ocean. The world seaweed industry is growing rapidly, particularly the aquaculture sector, and possibilities for sustainable seaweed utilisation in Mauritius are discussed. Most seaweed culture for human food occurs in temperate regions, and current successful industries in tropical environments, especially the culture of Eucheuma / Kappaphycus for carrageenans, are in developing countries with low average incomes, often involving the importation of non-indigenous species. Possibilities exist in the aquaculture of seaweeds including in integrated systems for bioremediation and/or as animal feed, as well as the potential for utilisation of abundant species as feed or fertiliser or in small value-added industries. As an example, the worldwide uses of Sargassum, perhaps the most abundant local genus, are discussed.