Cancun seaweed conditions update: very clean, without sargassum in most of Cancun and Riviera Maya

After a very difficult year for the tourism sector, for the first time in many months, Cancun and Riviera Maya are practically clean and free of seaweed, with only some places in Mexican Carribean with moderate amounts of algae, which will be cleaned gradually and naturally.

Beaches in Cancun are clean from sargassum today
Beaches in Cancun are clean from sargassum today

Important note: Holbox Island, Isla Blanca, Costa and Playa Mujeres since the beginning of November, present in their beaches a mixture of seagrass, seaweed and sargassum (in smaller proportion). Mainly dominating the seagrasses of the genera Thalassia (Turtle grass), Syringodium (Manatee grass) and Zostera (Eel grass) in more than 80%. Also in this mixture that arrived a few days ago, there are macroalgae of the genera Codium, Wallonia, Gracilaria, Acanthophora and Sargassum. All other points of tourist importance of Cancun and Riviera Maya, are mostly clean and free of sargassum.

The low presence of sargassum in the waters of the Caribbean Sea, the prevailing climatic conditions, the high tide, the direction of the prevailing winds, as well as the direction and intensity of the sea currents, have propitiated this condition in synergy, which will allow for a holiday period at the end of the year without the important presence of this macroalgae, only small isolated arrivals of sargassum are expected, of very low intensity along the entire coast of the State of Quintana Roo.

It is very important to recognize the worth and courage of thousands of inhabitants of the State of Quintana Roo, who every day went out to the beaches to clean up thousands of tons of sargassum that covered the beaches in the spring and summer months.

However, there is no need to sing victory, according to the opinion of scientists and international experts on the subject of sargasso, this will be a recurrent and seasonal phenomenon, so it is necessary to be prepared to face the arrival of this seaweed next year.

Much basic research is still needed to answer the most basic questions about this complex environmental phenomenon, which has severely affected the coasts of Mexico and practically all the countries of the Caribbean Region. It is also necessary to allocate more economic, technical and scientific resources to combat the incidence of the "Brown Tide" on the beaches.

Happy New Year's Eve holidays, we look forward to seeing you in Cancun and Riviera Maya.

Source: Hydrobiologist Esteban Amaro, Technical Director & Coordinator of the Sargasso Monitoring Network


The Sargassum Monitoring Network of Cancun publishes daily reports of the situation on 60 beaches of the Mexican Caribbean, based on satellite and drone images, and photographs of citizens.

Green: low presence of sargassum

Red: strong, excessive presence of sargassum

Orange: abundant presence of sargassum

Yellow: moderate presence of sargassum

Turquoise: clean of sargassum

Sargassum conditions are very dynamic and can change from one day to another, and even in hours, there may be differences of appreciation on the evaluation points referred to here.

The Sargassum Monitoring Network is made up of biologists, oceanologists, computer engineers, and hydrobiologists, and draws up reports of sargassum from satellite images provided by the Optical Oceanography Laboratory of the University of South Florida, and the System of Marine Monitoring of the National Commission for the Knowledge and Use of Biodiversity (Conabio).

The Network also takes its own videos and photographs daily with a fleet of 8 drones "that scan virtually the entire coast, from north to south." And they receive videos and photographs of the more than 40 thousand followers they have on Facebook.

Thanks to these three elements, satellite images, images of the drones, and images of our users, they can make a very accurate signalized map of how sargassum is in the entire northern and southern part of Quintana Roo.

The Secretariat of Tourism of Quintana Roo also publishes daily reports on the state of the beaches in the state in its social networks.


Sargassum is a large macroalga, meadow or dark green color, which lives in the seas and moves by the currents of the oceans. If the conditions for its growth are optimal, in less than twenty days it doubles its biomass (as it is happening), since it has the facility to grow very fast. In this way, the algae turn brown the paradisiacal beaches of the Mexican Caribbean and pose a real threat to the tourist interests of the region.

The macroalga reaches the Caribbean from two main sources: the Sargasso Sea, in the Bermuda Triangle, and a new area, north of the equator, where it accumulates off the coast of Brazil to enter the Caribbean.

Sargassum on beaches is an indicator of pollution and increased damage caused by human activity in the seas and Caribbean coasts, where there are irregular settlements and inadequate treatment of sewage and greywater.

The population is recommended to take precautions to carry out water activities due to wave and wind effects. Also, take extreme precautions when traveling on the road due to wet soil from the rains.

The sargassum arrival is a regional phenomenon that affects, without distinction, all the coasts of more than 30 countries, territories and different protectorates.

Sargassum is reported from the coasts of Cuba, Turks and Caicos Islands, Inagua, The Bahamas, Jamaica, Grand Cayman, Haiti, the Dominican Republic, Puerto Rico, Honduras and also the coastal region of Quintana Roo Mexico.

Also, further east, all the islands of the Lesser Antilles arc are affected, such as the British Virgin Islands, Saint John, Saint Thomas, Culebra, Antigua, and Barbuda, Montserrat, Guadeloupe, Martinique, Dominica, Saint Lucia, Barbados, Saint Vincent, and the Grenadines.

It also arrives in Granada, Trinidad, and Tobago, Curacao, Margarita Island, Aruba, the Atlantic Coast of Brazil, French Guiana, Suriname, Guyana, Venezuela, Colombia, Panama, Costa Rica, Nicaragua, Honduras, Guatemala, Belize, and the Peninsula of Florida in the United States.


Sargassum on the beaches of the Mexican Caribbean has brought not only turbid waters, but the death of 78 species, including fish, lobsters, and corals, as the sargasso decreases oxygen in the ocean, changes the acidity of the water and increases up to 10 times the levels of ammonium and phosphorus.

Eventually, the presence of sargassum will lead to a process of desertification in the shallow seabed and this may be an irreversible phenomenon. The problem is not these algae but the large quantities in which they are produced.

The sargassum seaweed had already been described two centuries ago. It is known that there are more than 500 species but only two of them are able to float (S.natans and S.fluitans) since most of them are fixed to the substrate. The Sargasso Sea was even known as a unique ecosystem, located in the North Atlantic and delimited by ocean currents. It was used by many vertebrate animals, soft corals or eels, species that occupy this ecosystem to grow and then migrate.

When this barrier was broken, the sargassum began to float until it invaded the Caribbean coast and today there are many doubts about it that scientists have not been able to explain clearly due to the lack of open data. Why was this barrier broken? Or how often do they reproduce?

According to Dr. Joseph Peter Montoya of the Georgia Institute of Technology, the presence of sargassum in the rivers of the Amazon that flow into the sea has blocked the transport of nutrients, as demonstrated by one of his analyses conducted from 2010 to 2018.

"Sargassum requires nutrients to produce biomass but in most of the ocean, the availability of nitrogen limits its production. What has been observed is that the seaweed concentrates and blocks the transport of nutrients that go from rivers to the oceans".

The oceans occupy two-thirds of the planet, so 2 out of every 3 puffs of the air we suck up are thanks to them, hence the importance of creating action plans. More information is needed to make more robust models, articulate national and international programs, restore and mitigate the effects of sargassum, use it sustainably and educate about the oceans.


Since 2013, when the first massive arrival of sargassum to the coasts of Quintana Roo was registered, its volume has increased exponentially each year and for specialists, businessmen and authorities of the three levels of government it represents a latent threat for the destruction of reefs, the erosion of beaches, the tourist contraction and, worst of all, the possible impact on the third source of income of the national Gross Domestic Product.

During these last six years, the strategies to address the contingency with public resources already exceed 470 million pesos (approximately 24.7 million US dollars), which have been enough to create a kind of emerging market where almost by spontaneous generation emerged "specialists" and "expert companies" in sargassum, offering an infinite number of solutions to control its dangerous arrival and its possible economic impact.

Sargassum clean-up on the beaches of Quintana Roo. (Twitter @AytoCancun)
Sargassum clean-up on the beaches of Quintana Roo. (Twitter @AytoCancun)

There were also new jobs such as the sargacero (responsible for cleaning the beaches) or unusual proposals to take advantage of the recycling of this alga in the manufacture of partitions, shoes, even fuel production. And with all this, another vein for government corruption was opened, as denounced by the business sector of the state and federal legislators.


With more than 1,100 people, workers from various municipal agencies began clean-up of the beaches in Cancun The program is called "Everyone against the sargassum". The objective is to attend the 12 public beach accesses of Cancún and it consists of collecting the sargassum directly on the shore of the sea. The aim is to attend the Dolphins, Whales, Marlin and Chac Mool beaches, and to transfer the seaweed from the coastal dune to its final disposal.


In the midst of a crisis due to the massive arrival of sargassum along the entire coastline of Quintana Roo, the president of the Ecological Group of Mayab (Gema), Araceli Domínguez, denounced that the municipality of Benito Juárez, Cancún, admitted heavy machinery to Playa Gaviota Azul, in violation of the rules established by the Ministry of Environment and Natural Resources (Semarnat), for the removal of macroalgae.

The activist explained that these actions are generating a complete loss of sand due to the compaction of the terrain and impact on the nesting of sea turtles.

The guidelines for the sargassum removal, which were established in 2015, include recommendations, for example, that the work should be carried out between the hours of seven in the morning and seven in the evening without touching the nesting and spawning area of the sea turtles.


The shrimp fleet of the state of Quintana Roo could be added to the sargassum collection in the high seas, due to the large concentrations of the algae that are located in the Atlantic Ocean towards the Mexican Caribbean.

From June 15 to October 21, the shrimp fleet, made up of 18 vessels, will be inactive due to the closure of the crustacean, which will allow them to help with the environmental contingency. Each of them could collect up to 70 tons of sargassum per day, which would be moved to deeper waters to meet their life cycle and die at sea. The idea would be to redirect the sargassum, collect it at sea, move it in the same boat and release it kilometers offshore so that the current itself will take it to deeper waters, so there would be no damage to the seafloor.

It could be a good strategy because it would allow collecting the seaweed in large quantities. It is an option if it can be implemented.

The shrimpers would join ships of the Mexican Navy that will help in the harvesting of the sargassum.


Within the Sargasso containment plan, the Navy announced that it will build barges to collect this seaweed that arrives on the beaches of the Mexican Caribbean.

It employs a Logistic Supply Vessel anchored in the vicinity of the Fifth Naval Region, based in Isla Mujeres, as a logistic support platform for the operations carried out by the Navy personnel in that area.

Likewise, there is a Research Ship to carry out sargassum containment operations at sea, with specialized hydrocarbon containment equipment. There is also an Oceanic Patrol and a Defender type vessel to support the laying of hydrocarbon containment barriers, as well as smaller vessels.

In the land operations, the Navy personnel carry out the picking with shovels and wheelbarrows of the sargassum that is contained by the barriers laid on the shoreline.

Likewise, naval personnel specialized in programs against marine pollution, make the laying of the barriers along the coastline and relocate them according to the needs and coordination carried out with the corresponding dependencies, making use of smaller vessels assigned.

Semar said it has a coastal patrol plane, as well as three helicopters to carry out aerial tours, in order to monitor the presence of sargassum in the area of ​​operations and be able to guide and direct the surface units to the areas of higher incidence of sargassum.

By Mexicanist

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