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Sheet 10: Impacts on the economy

Similar situations in all Caribbean countries

Whether it is the Gulf of Mexico, the south-eastern coast of the United States, or the Greater and Lesser Antilles, the entire Caribbean plate is affected by Sargassum event and the economies linked to tourism and fishing are being impacted. During important seaweed events, beaches and all marine activities can become unusable, with seaside restaurants registering record numbers of missing customers, deserted hotels and fishermen staying on land. In Martinique and Guadeloupe, economic losses were estimated at 6 million euros in 2018. 

The Caribbean is already facing a vulnerable economic situation linked to climatic hazards, and the potential development of green economies linked to Sargassum heralds important investments from local actors.


Local residents review their budgets

The first to be affected by Sargassum strandings are highly exposed areas inhabitants. The risks are obviously health-related, since prolonged exposure to Hydrogen Sulphide, a neurotoxic gas, causes numerous symptoms (irritation, development of chronic bronchial illnesses, headaches, nausea, etc.), but the consequences are also financial. Hydrogen Sulphide is, in addition to being neurotoxic, is a corrosive gas that eats away at anything metallic. Coins, household appliances, vehicles, air conditioning systems… Metal components do not last long in the face of these gases that can be present for long if the algae is not collected and stored far from inhabited areas.

In Martinique, a project financed by the National Research Agency in partnership with the Territorial Collectivity of Martinique has aimed to provide technical and legal solutions to the corrosion of metallic materials since 2021, to promote better management of material damage linked to Sargassum. The project is scheduled to last three years and includes three lines of research: atmospheric corrosion, marine corrosion and ways to legally face the accelerated degradation of materials by corrosion. Sensors have been installed in all exposed areas to measure the quantities of Hydrogen Sulphide and Ammonia as well as the salt content of atmospheric fallout. However, to date there is no concrete solution to the problem, in Martinique or elsewhere. 

Residents are also affected by the devaluation of their property caused by the foul odors, causing the mainly invisible migration of certain residents, authorities are only just beginning to identify them. 

In 2019 in Mexico, the army to the rescue of tourism

Important events require important measures. In 2019, on the Mexican coast of the state of Quintana Roo (whose beaches are world famous: Cancún, Puerto Morelos or Las Islas Mujeres), helicopters and ships of the Mexican navy were dispatched to spot and stop the rafts of seaweed when the hastily installed booms were unable to protect the beaches. 

Two visions clash in the country: for Quintana Roo State government and the tourism industry, Sargassum is an economic and sanitary disaster, whereas it still represents a minor risk according to the President and federal government. The figures speak for themselves: there was on average a 2.5% drop in tourist numbers between January and September in 2019 compared to 2018.  Yet tourism accounted for 1,541 billion pesos in 2018 (81 billion euros) i.e. 8.7% of GDP (Gross Domestic Product)- the country’s third largest economic sector, a major and essential sector. 

Throughout the Caribbean, beachfront restaurants are suffering the full brunt of tourists fleeing due to decomposition gases emitted by the algae and often go days without a single booking. Hotels are not spared, having to sometimes close their establishments temporarily, as well as yacht charter companies, diving clubs and other seaside rental companies (jet-ski, canoe, windsurfing, etc.)- all are affected.


In the French Antilles and Guadeloupe in particular, two dismissals directly linked to Sargassum have been registered, by a hotel and a restaurant owner due to visitors dropping in 2018. While these measures may seem anecdotal in view of the scale of the phenomenon and the number of professionals affected, they are in fact the tip of the iceberg. The whole economy linked to the sea and beaches is affected. In Guadeloupe still, the estimated loss in 2018 amounted to €5 million, including €67,200 for restaurant owners alone, even though very few are insured for sargassess-related damage. 

Everywhere, joint operations to install deflecting or blocking booms (preferred solutions) to clean beaches or to prevent strandings are multiplying, and if the operations are expensive (a day’s cleaning can cost up to 6,000€ for a small commune), they are essential for Caribbean tourism, in danger of suffering from dirty beaches. This accelerates the drop in visitors while the quantities of Sargassum in the sea continue to rise every year.

Impacts on fisheries and shipping lanes

Economic impact is therefore reflected in the reduction of tourist activity, but also in a significant hindrance to small-scale fishing and maritime transport. In Haiti, fishermen (who highly contribute to the economic and social life of the country) are hindered by the regular and massive Sargassum events. The Haitian Maritime and Navigation Service is therefore getting organized to identify places where Sargassum has washed up and the areas where navigation can be dangerous for sailors who leave for sea.

Since September 2019, the Caribbean Institute of Natural Resources based in Trinidad and Tobago has been working with other fisheries related or research organisations (University of the Antilles, Caribbean Fishermen’s Organisation Network) but most importantly with the marine authorities of Antigua and Barbuda, Barbados, Belize, Guyana, Jamaica, St. Lucia and St. Vincent and the Grenadines to implement the development of a stewardship dedicated to the ecosystems and livelihoods of small-scale fisheries in the Caribbean. 

The objective of the UN-supported Steward Fish project (which ended in April 2022) is to empower fishermen along the entire fisheries value chain in order to get involved in resource management and provide institutional and financial support, as well as material support in the face of Sargassum infestation. 

The fisheries industry is still being permanently affected by the fact that many sailors are unable to go out to sea (an average of 22 days of immobilization in Martinique and Guadeloupe).


Sargassum and the development of green economies

The green economy, which constitutes a lever for sustainable development, is based on several factors, namely: the management of natural and energy resources, and environmental protection in particular. In French overseas territories, ways of using Sargassum can be integrated into this economy and the issues that this raises are major: the use of Sargassum as biogas (see the sheet Using sargassum for sustainable development) can for example constitute a new resource for territories subject to strandings, even if it is not an unlimited resource insofar as Sargassum events are irregular. In conclusion, while these avenues are becoming clearer with time and research, many of the negative aspects caused by Sargassum are still awaiting solutions. 

A 2018 IFOP survey confirmed for the Association Chimie du Végétal that 87% of the French population affirm seeing biobased products positively. The market for sargassum-based compost is expanding rapidly throughout the Caribbean, for example (see the “Sargassum recovery: agriculture, agri-food and cosmetics” sheet). All of these elements are pushing local and international players to invest in ways to use Sargassum. 


BBVA Group
Outremers 360
Gobierno de Mexico
Agence Nationale de la Recherche
Collectivité Territoriale de Martinique

Nations Unies
Institut Caribéen des Ressources Naturelles
Caribbean Regional Fisheries Mechanism
Institut d’Émission des Départements d’Outre-Mer – Banque de France
France 24