Sargassum is choking the white sand beaches of the Caribbean and exacerbating an economic and health crisis

The Caribbean sandy beaches, clear turquoise waters and colourful coral reefs with an incredible number of marine life have long been the pride of the islands.

The big three – sun, sea and sand – have created this tropical paradise the region most depending on tourism on the planet.

But now all that is in peril. The explosive growth of a Type of algae called Sargassum is wreaking havoc on the economy, coastal environment and human health on all islands.

I study the interface of Critical infrastructure and disastersparticularly within the Caribbean. The Sargassum invasion has worsened because it broke out within the region in 2011. Forecasts and the algae which have already washed up suggest that by 2024 one other alarming yr.

A map shows Sargassum around many of the eastern Caribbean islands.
By the top of May 2024, Sargassum levels were already high around many eastern Caribbean islands. Meteorologists expect more Sargassum to clean up on many islands and within the Gulf of Mexico in June.
NOAA and University of South Florida

The Sargasso Sea

The Sargasso Sea is sometimes called golden floating rainforest for its huge floating Sargassum flowers and the good diversity of marine life that it supports.

It is the one Sea of ​​the world without land bordersInstead, it’s bordered by 4 currents of the Atlantic Ocean: the North Atlantic Current, the Gulf Stream, the North Atlantic Equatorial Current and the Canary Current.

A map shows the Sargasso Sea in the middle of the Atlantic Ocean, west of Florida and Georgia, and the Sargassum Belt through the Caribbean
The Great Atlantic Sargassum Belt and the Sargasso Sea.
JL López Miranda et al. via Wikimedia, From

Without human intervention and under normal conditions, Sargassum is a great thing. It has existed within the Caribbean for hundreds of years, providing habitat and food for marine animals, including threatened and endangered species resembling the Porbeagle sharks and that Anguillid eel.

However, conditions over the past decade across the Caribbean, the North Atlantic and the Gulf of Mexico were anything but normal.

Since 2011Huge mats of Sargassum seaweed were washed up on Caribbean islands. On land they pile up right into a dead, stinking mass.

An illustration showing sargassum washed ashore and some of the problems it causes, including health impacts, inaccessible beaches, and clogged water intakes.
(1) Sargassum flows from an enormous marine bloom often known as the Sargassum Belt are carried ashore by ocean currents. (2) Free-floating Sargassum provides food and habitat. (3) On land, nevertheless, it rots and clogs water inlets and beaches.

These Sargassum events were occurring more continuously and last more, and the Algae quantity is increasing.

The situation has turn out to be so bad that NOAA has weekly Sargassum flood risk index in collaboration with the University of South Florida. They predicted that 2024 one other terrible yr for the Caribbean.

Environmental pollution promotes dangerous algal blooms

So what causes the explosive growth of those algae? Studies have identified environmental pollution to which the Caribbean region itself has contributed little.

Humans alter the nutrient cycle by releasing Fertilizer runoff and industrial wastewater in rivers that send Phosphates and nitrates in river systems and into the oceans. These are necessary nutrients for plant growth.

An underwater photo looking up at a diver with seaweed on the surface above her.
A diver swims under a sargassum mat.
Then Eidsmoe via Flickr, From

A rapid increase in livestock farming, forestry and agriculture along the Amazon in South America is a source that gives huge amounts of nutrients washed into the riverwhich ends within the Caribbean Sea.

Another wrongdoer is the Mississippi River, which carries nutrient-rich wastewater from farms and industrial plants. into the Gulf of Mexico.

The Congo River in Africa also leads Pollutants within the sea on account of deforestationand burning forests can release nutrients resembling nitrogen, phosphorus and iron, which promote algae growth.

These pollutants are swept away by ocean currentsIt is believed that a rise in phosphate and nitrogen pollution combined with warming seas has led to increased algae growth, which is often carried by currents from the Sargasso Sea and created the Sargassum Beltwhich continues to at the present time throughout the Caribbean.

Coasts and fishing industries cannot escape the damage

In small quantities, Sargassum plays a task in Beach replenishment. But when it floods the coasts, the ocean grass rots suffocates beaches And reduces the oxygen content within the waterwhich ends up in the death of fish and damage to sensitive coral reefs.

Boats moored among seaweed in a harbor. The beach between the photographer and the boat in the center of the picture is covered with seaweed.
Sargassum can penetrate ship propellers and make it difficult to approach the coast. This is what happened in Puerto Rico in 2015.
AP Photo/Ricardo Arduengo

The massive influx of Sargassum has also disrupted fishing operations. Fishermen are struggling to make a living as Sargassum Reducing their catchesThe seaweed has damaged fishing equipment and boat engines and restricted access to ports and moorings.

In addition, Sargassum Arsenic concentratewhich creates a risk of contamination of the fish and harm to the individuals who eat it.

Sargassum on land poses a threat to public health

Sargassum rots quickly when stranded. Within 48 hours it begins decompose, releasing hydrogen sulphide and ammoniaAt certain concentrations, these gases will not be only toxic to the marine environment but in addition to human health.

There is a growing variety of reported cases of neurological, digestive and respiratory diseases in reference to the pollutants emitted. Guadeloupe's air quality monitoring institute Gwad'Air has red alarms issued in recent times on account of dangerous levels of hydrogen sulfide emitted from rotting Sargassum.

The growing Sargassum problem.

The most Common symptoms People living near Sargassum suffer from headaches, dizziness, stomach aches, coughs, skin rashes, eye disorders and mood swings. Sargassum odors have led to a rise in nausea and headaches in School-age childrenPregnant women within the region are also affected, with increasing reported cases of preeclampsia.

Sargassum has also clogged Water inlet pipes for desalination plants and power plants that Seawater for coolingwhich ends up in the shutdown of those units.

In the British Virgin Islands, the intrusion of Sargassum into the predominant desalination plant in 2023 led to smelly tap water and sporadic water shut-offs. In Virgin Gorda And St. CroixPeople have reported smells, burning sensations and rashes from their tap water.

Sargassum blooms also damage the economy

Million tons from dead and rotting seaweed Washed-up goods can have far-reaching economic consequences.

The smell of rotting seaweed attracts insects, which is a repulsive for some touristsCleaning the beaches and disposing of tons of garbage, typically in landfills, cost the Caribbean about 120 million US dollars in 2018.

This doesn’t include the economic losses for hotels, fisheries and other businesses.

Small businesses like Jet Ski Rental whose sources of income depend upon the coast needed to be closed temporarily since the rotting mass released foul-smelling gases.

Is there an answer?

Research and there are entrepreneurial initiatives which can be attempting to cope with the seaweed. Companies have tried to in fertilizer, fodder And concretebut to this point only on a small scale.

Sargassum cleanup in Martinique in 2023.

Governments have made little progress, aside from agreeing to some Fisheries management rules to guard endangered speciesSome countries have Design of management strategieshowever the measures often deal with protecting the tourism industry, little attention to fishermen and native communities.

The Sargassum invasion is fueled by global pollution, and a worldwide response is required to deal with it.

The United Nations Environmental Programme has called for increased international cooperation to know the causes and effects of Sargassum invasions and to search out ways to assist affected countries. But to this point the international community has done little to deal with pollution at the foundation of the issue.

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