The Caribbean face since 2011 a phenomenon of stranding of Brown algae. The species are Sargassum fluitans and Sargassum natans.
According to a recent estimate cited by the french Ministry of ecology, 180 Sargasso hectares are scattered along the Caribbean coast, approximately 60 000 tons of dry matter.
The origin of algae Sargasso
Recent studies have shown that kelp do not come from the Sargasso Sea, located in the North Atlantic, but rather an area located off the Brazil. The presence of nutrients, temperatures and currents are favourable to the accumulation of algae Sargasso in this region. Climate change so is perhaps one of the causes of this algal blooms.
A better understanding of the phenomenon
To combat this natural phenomenon that threatens the economy and generates many nuisances, the establishment of infrastructure management and valorisation of the Sargasso becomes necessary.
Negative impacts
Health impacts : respiratory genes in susceptible persons caused by the release of H2S decomposition of algae-related ;
Many ecological impacts :
– on wildlife, threats of protected species,
– on the coast, mountains of algae and debris and remnants of dams nonconforming or inappropriate.
Economic impacts : the closure of access to some beaches and the strong smell of H2S penalize tourist activity (Hotels, restaurants), as well as the fishing and aquaculture sector
Possible uses and valorisation of the Sargasso
The global opportunities of macroalgae relate to 89% food, 7% fine chemicals and 4% the production of hydrocolloids. Algae are at the origin of compounds used by the food industry, as thickeners, gelling agents, emulsifiers, stabilizers, as alginates, polyphenols, fucoxanthrine… The usefulness for flocculation in wastewater treatment and the determination of heavy metals has been demonstrated on certain species of Sargassum.
Agricultural valuation : the Sargasso can serve as natural fertilizers in agriculture (Potash), direct application, animal feed, mulching, biological control, composting.
Cosmetic enhancement, Food and green chemistry (biofuels, renewable energy, other uses are being studies such as the transformation into charcoal or bio plastic).