Reef check: presence of green algae

Organized every year since 2008, this year’s Reef Check took place on September 17-19, off the coast of Galion, Caye Verte, Pinel, and Rocher Créole. Two volunteers, Théo Feger and Guillaume —of Jorakhae Free Diving School — joined forces with the Réserve. The data is still being evaluated but, one year after hurricane Irma, observation revealed a high presence of green filamentous algae, especially on coral reefs and plant beds, but also washed up on the beaches, including Pinel. These algae are generally present in these areas, but usually on a seasonal basis and of a smaller quantity. Their abundance this year is an indication of organic coastal pollution, with water treatment stations at but 50% of their capacity, according to a press release issued by the EEASM in October 2018. The proliferation of these algae is promoted by strong rains, at which time runoff water is filled with organic materials and nutrients, and this year also from non-purified wastewater. Consequently, the soil leaching and coastal pollution enrich the shoreline milieu, which benefits the algae, but to the detriment of the coral that suffocates. The degraded quality of the coastal waters represents the first cause of deterioration of the marine biodiversity in Saint Martin.