Sargassum, the brown tide that is invading the Caribbean

The phenomenon has broken records this year and has become one of the great environmental concerns of the coastal areas of the region

Tourists swim at Xcalacoco beach next to sargassum in Playa del Carmen, Quintana Roo.

More than six centuries ago, the first European expeditions that crossed the Atlantic to reach the American continent sighted a phenomenon known as sargassum. While documenting it, some of those explorers feared that their ships would get stuck in that brown tide. Now, in the last decade, sargassum has been invading the Caribbean coasts, destroying its ecosystem and becoming a threat to the tourism sector.

It all began in the summer of 2011, when sargassum started to accumulate on the beaches of many destinations with crystal clear waters and white sands. Mexico was one of the first countries to report it, but this environmental problem, which is lethal to many species and also harmful to human health, concerns almost the entire Caribbean region. This year, the amount of sargassum has already reached historic figures in the Atlantic Ocean: in June, more than 24 million tons of the “brown tide” were recorded in the Caribbean coast, from Puerto Rico to Barbados, according to a report from the oceanography laboratory of the University of South Florida.

What is sargassum?

The term refers to an uncontrolled growth of the species Sargassum fluitans and S. natans, brownish seaweed that live in suspension in the seas and move along the Atlantic, dragged by ocean currents. Although most seaweed live in the depths, with their roots attached to the bottom of the sea, these two species can live at the surface because they have gas vesicles, an adaptative mechanism that improves photosynthesis and allows them to spend their lives floating, explains Rosa Rodríguez, a marine biologist at the Institute of Marine Sciences and Limnology of the National Autonomous University of Mexico (UNAM).

While the uncontrolled accumulation of these algae is toxic in coastal regions, causing the massive death of many marine species, in the open sea they play a very important role in maintaining ecological balance. The Sargasso Sea, in the North Atlantic Ocean, is an exceptional ecosystem that provides food and shelter for hundreds of species, some of them unique to this floating habitat. In addition to serving as a platform for the protection and sustenance of marine fauna, it is part of the migration path of species such as eels, turtles and whales.

Why did it become a problem?

When the unrestrained blankets of sargassum reach the coast, they prevent light from filtering to the seabed, which is essential for the biology of corals and types of algae that produce food through photosynthesis. This, in turn, affects the biodiversity of the system they support.

A woman walks on a bridge surrounded by sargassum in Puerto Morelos, near Cancun.

One characteristic of sargassum is how quickly it can grow: in favorable conditions, it is able to double its biomass in less than 20 days. When the seaweed decompose on the shore, they consume large amounts of oxygen, causing anoxia and emitting toxic gases like hydrogen sulfide and methane, which are very dangerous for humans and can cause the mass death of many species.

The excess of nitrogen and phosphorus derived from the putrefaction process serves as fertilizer for them to grow more, generating leachates, sulfidic acid and arsenic, which are responsible for the fetid and rotten smell that has now become common in some Caribbean tourist destinations. Yet another problem, says the UNAM specialist, is the poor disposal of sargassum, which ends up becoming a pollutant.

Why is it produced, and where does it come from?

According to the strongest hypotheses, climate change is behind the spread and uncontrolled growth of sargassum. For years, various scientific studies have warned of how changes in the ocean currents due to the melting of the poles and glaciers, as well as the excessive ocean fertilization, are making this an increasingly common phenomenon.

The discharges and waste from industries and agriculture at the mouths of the great rivers of South America, such as the Amazon and the Orinoco, whose sediments and organic matter are pushed north by the currents, have caused seaweed to reproduce at a record speed, creating the Great Atlantic Sargassum Belt, a buildup of seaweed that is devastating the Caribbean coasts. “It is a clear example of how climate change affects us directly and indirectly,” points out the biologist.

Which regions are being affected?

Far from being an isolated phenomenon, the problem is impacting a large part of the Caribbean. The beaches of Belize, Honduras, Jamaica, Cuba, Mexico, the Dominican Republic and Barbados, or islands such as San Andres, Guadeloupe or Martinique, among others, are affected by the blankets of seaweed every year. “But large arrivals of sargassum have also reached the north coast of Brazil and even Florida,” says Rodríguez. This brown tide is not only impacting the Caribbean. The biologist explains, “it arrived in the Gulf of Mexico long before, but not in such high volumes.”

Sargassum at Yabucoa beach, in Puerto Rico, last august.

The first report of the appearance of sargassum came from local fishermen and a newspaper in 2011, according to Chuanmin Hu, an oceanographer with the University of South Florida team, which began tracking its growth in the Gulf of Mexico in 2006.

Is sargassum here to stay?

Hu is the author of a study that in 2019 warned that a change in the ocean currents was increasing the possibility that recurrent sargassum blooms in the tropical Atlantic and the Caribbean Sea would become the new norm. According to Hu, the data suggests that the amount of sargassum that reaches the coasts is growing steadily. According to Rodríguez, even though there is not enough information on the biomass that is reaching the different regions of the Caribbean, which fluctuates every year, “everything suggests that not only the problem will remain, but it will take a turn for the worse.”

Can it be controlled?

Since the problem was pointed out by environmentalists and hotel owners, governments have sought ways to clean their affected beaches in order to recover tourism. Nonetheless, Rodríguez explains that the resources invested so far have not been efficient. “Only a small area of the coast is being looked after, and ecosystems that are also affected by sargassum, like the mangroves and the jungle, are not being cared for,” she points out.

What’s more, the strategy of directly removing the buildup of seaweed from the coasts has a very negative impact. “A little sargassum helps prevent beach erosion, but when it’s a lot it has the opposite effect. And with the heavy machinery that is used to extract the seaweed, they remove a lot of sand,” says the UNAM expert. Another problem that stems from the removal of sargassum is how poorly they dispose of it. “Sargassum has a lot of arsenic, but also cadmium, lead and other heavy metals, as well as dangerous bacteria that pollute the environment,” she warns.

What to do with sargassum?

The arrival of sargassum in the Caribbean can be an opportunity for various industries, and in recent years different initiatives have promoted its use as a raw material.

The different properties of sargassum can be used by sectors ranging from construction to pharmaceuticals or the energy industry. Research centers and universities, for example, are using it as a source of biofuel, thanks to its composition of lignin, cellulose and hemicellulose; sodium alginate, a polysaccharide that can also be found in sargassum and that acts as a thickener, is used in the textile industry and for haute cuisine.

With the aim of promoting the principles of the circular economy, which uses everything while creating added value, some companies are taking advantage of the impurities left over from the alginate extraction process, such as fucoidans. These biopolymers, whose antitumor and immunomodulatory properties are currently being researched, could even be used as cancer therapies, according to some studies.

Source/Fuente: El Pais 18 august 2022


Dominican Republic : Punta Cana SEAWEED Problem (2022): Everything You Need To Know!!

Does Punta Cana have a seaweed problem? This should be your first question if you’re planning a beach vacation to anywhere in the Caribbean, not just Punta Cana. Because you may have heard about the sargassum problem recently, but, it has been a big issue for several Caribbean countries for quite some time.

Sargassum seaweed has been a big problem for the Caribbean countries since 2011. However, the frequency and quantity of sargassum washing up on Caribbean beaches has considerably increased since 2015.

The year 2018 was particularly bad, as a large amount of sargassum seaweed landed on the shores of many Caribbean countries, ruining their pristine white sand beaches and spoiling the holidays of many tourists.

Punta Cana Seaweed problem 2022: Everything You Need to Know!!

Does Punta Cana have Seaweed problem in 2022?
Since 2018, Punta Cana (Dominican Republic), like the rest of the Caribbean countries, has been reporting masses of sargassum seaweed on its beaches. Unfortunately, the year 2022 will be no exception.

Punta Cana, like other Caribbean countries, will face a seaweed problem in 2022. In fact, at the start of 2022, residents of Vernon and Punta Cana reported a trace of sargassum washed up on their beaches.

In other words, if you do proper research prior to planning your vacation to Punta Cana, you can definitely enjoy the world-famous pristine white sand beaches of Punta Cana without encountering sargassum.

How do Dominicans avoid Seaweed?
The majority of Punta Cana hotels, as well as the Dominican government, have initiated numerous large-scale measures to combat the seaweed problem.

Indeed, compared to many other Caribbean countries, numerous hotels in Punta Cana have made major investments in cutting-edge technology and are having greater success in tackling the seaweed problem.

This, however, is a temporary issue, and most days there will be no seaweed at all. Even when this occurs, beaches are often cleaned quickly. Also, not all of Punta Cana’s beaches have a seaweed problem.

Punta Cana Sargassum Seaweed Forecasts for 2022?
The Optical oceanography laboratory at the University of South Florida reported in its monthly bulletin that the amount of sargassum in the Caribbean sea has increased, indicating that 2022 may be another year with high seaweed concentrations.

However, you must understand that the sargassum seaweed problem is a natural phenomenon. It originates in the sargasso sea but washed up on the shores of Caribbean countries due to ocean currents.

Sargassum level varies beach by beach, day by day, season by season, and place by place. Sargassum, in other words, is very difficult to track and very unpredictable.

However, if you want to know the current seaweed conditions you can check This website shows the beaches that are currently affected by sargassum.

So, the best way to ensure a sargassum-free vacation in Punta Cana is to either stay on one of Punta Cana’s seaweed-free beaches, such as Bayahibe or Macao beach or to do some research and stay in hotels that are successfully tackling this issue.

How bad is the Seaweed Problem in Punta Cana?
Sargassum seaweed has been a major issue for nearly all Caribbean countries since 2015. As a result, the Dominican Republic is not the only country dealing with this problem.

When it comes to the sargassum crisis, 2018 was the worst year on record for all Caribbean countries, including the Dominican Republic.

This is referred to as the 2018 Great Sargassum Disaster, which had a huge impact on the Caribbean countries’ tourism industries.

Since then, the Dominican Republic’s government and most of Punta Cana’s hotels have taken numerous big initiatives to address this issue, as tourism is the country’s main source of income.

For instance, almost all hotels in Punta Cana employ dedicated staff that works hard to keep beaches sargassum-free on a daily basis.

Additionally, the majority of Punta Cana is protected by seaweed barriers designed to prevent sargassum from reaching the beaches.

When is the Seaweed season in Punta Cana?
Sargassum seaweed prospers in hot weather and nearly disappears in cold weather.

That’s why you will see that Punta Cana is most affected by the seaweed problem in the summer months whereas this problem becomes quite rare in the winter months.

Punta Cana has the largest level of sargassum seaweed in the summer months (June to October), whereas the sargassum problem is fairly rare in the winter months (November to May).

Most affected Beaches by Sargassum in Punta Cana
Cabeza de Toro and Cap Cana are the most affected areas in Punta Cana by seaweed. However, as I previously stated, this is a transitory problem that varies from day to day, season to season, and place to place.

But, keep in mind that these areas are now protected by seaweed barriers and that the hotels in these areas have dedicated staff that works diligently day and night to keep the beaches clean.

Best Sargassum-free Beaches in Punta Cana
It is true that several beaches in Punta Cana have seaweed problems. However, there are still numerous places in Punta Cana that are completely sargassum-free, allowing you to enjoy Punta Cana’s world-famous gorgeous beaches without concern of seaweed.

If you are looking for a sargassum-free beach vacation or to enjoy your vacation with complete peace of mind, Bayahibe town is undoubtedly one of the best places to visit near Punta Cana. Bayahibe, a beautiful resort town about an hour’s drive from Punta Cana, offers pristine beaches free of seaweed all year.

Also, Macao beach along with beaches a Uvero Alto are other excellent options if you want sargassum-free beaches. You won’t have to worry about sargassum if you visit these places at any time of year.

On the Dominican Republic’s northern coast, sargassum is almost non-existent. As a result, popular beach destinations on the Dominican Republic’s northern coast, such as Puerto Plata, are also excellent options for a sargassum-free beach vacation.


Is Sargassum Dangerous to Humans?
Sargassum seaweed is usually harmless to humans when it is on water. However, once it reaches the beach, it begins to rot. Sargassum decomposes into stinging thick layers on the surface of the water, depleting the oxygen in the water and destroying the marine life in the area.

This rotting seaweed’s huge hips detract from the beauty of pristine beaches, and its rotten egg odor makes water activities and swimming nearly impossible and extremely uncomfortable.

How to Check Current Seaweed conditions before planning a vacation to Punta Cana?
Sargassum is definitely a big concern for tourists planning a vacation to Punta Cana. That is why, prior to planning your vacation, it is important to do proper research on the sargassum conditions at the beach or hotel you intend to visit.

Now, let us discuss how you check current Sargassum conditions to ensure that your vacation is sargassum-free:

Live Camera
The most effective method of monitoring the current state of beaches in Punta Cana is via live cams.

It’s a well-known fact that the majority of hotels in Punta Cana have live cameras facing the beaches. These live cams allow you to easily track the current sargassum conditions on the beaches.

Check this Website is a website that keeps an eye on the current sargassum level on the beaches. You can visit this website and see which beaches are currently affected by sargassum seaweed.


Source: – august 2022