The battle against Sargassum… is there finally light at the end of the tunnel?
In the latest article on the subject, on 3 September, the unauthorised nets were suspended following a ban on anchoring… Since then, no nets have been installed, but it would appear that things are finally moving forward. An update from the companies, the Local Authority, the Prefecture and the association of affected local residents.
September 2022: first steering group meeting. The Prefecture and the Local Authority announced the ‘installation, on a trial basis’ in May 2023, before the start of the season, of diversion nets in Cul-de-Sac Bay and Embouchure Bay. However, a two-year study was required prior to any deployment. The local authority was also to install automated fixed sensors along the affected coastlines to continuously monitor hydrogen sulphide emissions.
September 2025: the environmental department reported that the nets were ready but that prefectural authorisations were still pending. However, the Prefecture had not received any application at that date. Once the application was submitted, it was processed in record time. The Prefecture confirmed that everything was ready in June.
In the meantime, the €1 million contract was approved in October 2025 and installation, following the Prefecture’s approval, was scheduled for June 2026. In May, the date was postponed to July, pending delivery of the nets. The nets arrived in
mid-July, but the date was postponed to August, this time without justification. In August, the installation was postponed until September to allow time for the implementation of the anchoring ban, set for 11 September. On 17 September, during the Territorial Council meeting, President Mussington indicated that it would be better to wait until the end of the hurricane season… and here we are.
A total of 850 metres of barrier netting, to be positioned in Cul-de-Sac Bay and at the mouth of the Étang aux Poissons, had been planned. The Collectivité’s environment department, contacted on 22 October, has now announced that the nets will be installed in November at Cul-de-Sac and, subsequently, at the mouth of the Étang aux Poissons.
In fact, ATSM (Antilles Travaux Sous-Marins), the company responsible for the installation, was only paid last week, which explains this latest delay. Its manager confirms that the nets will indeed be installed in late November. For the Environment Department, installing the nets at this time of year will enable them to assess how the nets perform right from the start of the season, when currents are weaker.
As for GTN, the company responsible for collecting sargassum, its manager states that ‘the Collectivité owes a significant amount’; the work carried out has not been paid for. However, according to the Collectivité, the invoices exceed the amounts stipulated in the public contract, whilst the number of tonnes collected this year – 9,700 tonnes – is significantly lower than that of 2025 (16,000 tonnes). Nevertheless, the company has decided, on its own initiative, to invest in a new machine for pre-stranding collection with the aim of improving the quality of the collection.
New machine and new partnership
With a design quite similar to the Sargator, and operating on the same principle, GTN’s new amphibious machine is not intended for use on the open sea. Nevertheless, it will be able to collect Sargassum from the water near the shore before it washes ashore (the 300-metre strip falls under the jurisdiction of the Collectivité). For the manager of GTN, who has invested in this new device, the aim is to be more efficient. The immediate benefit is that far less sand is removed than with mechanical removal on land. This also limits the release of gases, which occurs when the seaweed comes into contact with the shore. The machine, manufactured in the United States, was transported this week to the Cul-de-Sac jetty to undergo testing in the coming days. It remains to be seen whether, given the administrative complexities of public procurement, this change in collection equipment will be possible. This is a point on which the Local Authority and the Prefecture have indicated they will be vigilant, as amending a public procurement contract (2024–2029), which sets the price per tonne, will require proof that this solution offers better value for money, either at the same cost or with a higher yield.
As for the sensors, the proposal from the shortlisted contractor will be submitted to the next Executive Council meeting. However, the installation, annual maintenance and data analysis – which fall more within the remit of the Regional Health Agency (ARS) – will be co-funded by the Collectivité and the State.
Things are also taking shape within the anti-sargassum collective. Citizens affected by the strandings have decided to organise themselves into an association in order to carry more weight with the authorities. But to be more effective, the association could also raise funds – from housing estates, for example – to finance projects to combat Sargassum; a way of overcoming the difficulties involved in joint action between the private and public sectors. The association is expected to be established by early November.
