Sargassum: Diversion barriers to be installed soon
After more than two years of studies and administrative procedures, the "anti-sargassum nets", announced in 2022, will finally be installed. The local authority plans for 700 meters of barriers. in Cul-de-Sac Bay in August, then another 200 meters into the bay at the mouth of the Étang aux Poissons (Fish Pond) (Orléans district) in OctoberA project costing €896.550, with €320.000 funded by the State.
The model chosen by the COM is the Mursargaz P1000 from the Spanish company MarkleenA costly choice made by the local authority, which favored the model benefiting from the best feedback, particularly in the Mexico and Saint-DomingueThese floating and flexible barriers are positioned to utilize currents and divert the algae to a single collection point.
A solution designed to facilitate the sargassum collection and to limit their impact on the beaches of the island's northeast, which are particularly exposed. Second Vice President Bernadette Davis, however, points out thatthere is “no guarantee” and that, while the model has proven successful elsewhere, all solutions remain “experimentalOriginally scheduled for June, The installation has been postponed until August due to a delivery delay from the manufacturer, linked to “a disruption in international supply chains”.
At Cul-de-Sac, the The collection point will be located south of the bay. and “should not have any more of an impact than before” on homes, assured Igor Rembotte, director of the environment. After discussions with local residents, The COM is nevertheless planning a third dam point in this location to prevent a potential overflow of algae.
Environmental studies have concluded that a limited impact on underwater flora and faunaThe dams will be installed on sandy bottom, without reefs or seagrass beds. The nets, which descend to only 70 cm deepThey also allow animals to move freely under the facilities.
Anchoring is prohibited within 25 meters of the dam.
At Cul-de-Sac, the two sections of the dam will be separated by a pass to maintain nautical activity, in particular to serve the islets pinel et Uproar. Anchoring will be prohibited less than 25 meters on either side of the damThe COM also points out that, Since a 1993 decree, the mooring is “In theory” already banned in the bay and invites users to move their boats.
Installation and maintenance will be provided by Antilles Underwater Works (ATSM), which won the public contract in December 2025. For one yearThe company will intervene in case of damage. It is also training two young people from Saint-Martin in the trade of diver to ensure the maintenance of the dam. In the event of a cyclone, The nets can be dismantled within 48 hours. and secured. Users are asked to report any damage to the local authority. _DR
Why is there so much sargassum?
Naturally present in the Atlantic, sargassum seaweed has been washing ashore in massive numbers in the Caribbean since 2011. Its proliferation is fueled by nutrient runoff from major African and South American rivers, largely due to intensive agriculture, as well as by ocean warming. Winds and currents then carry it towards the Caribbean. In Saint Martin, the Atlantic coast is particularly affected. As it decomposes, the seaweed releases hydrogen sulfide (H2S), responsible for the odor and potentially harmful to health. Scientists now consider this phenomenon to be ongoing.
