Sargassum barriers in the Riviera Maya

Along the most affected stretches of the Mexican Caribbean, the first line of defence against sargassum is a floating fence. These offshore barriers, known in Spanish as barreras antisargazo, are anchored a few hundred metres out and are designed to catch the seaweed at sea, where boats can collect it, before it reaches the beach and begins to rot. They are the most visible part of a much larger containment effort, and they are also the most misunderstood.

A barrier is not a guarantee of clear water. Its performance depends heavily on the strength of the currents, the direction of the wind, the size of the swell and how quickly crews empty the seaweed that piles up behind it. This guide sets out where the main barriers are, which organisations installed each one, and an honest assessment of how well the beach behind it tends to stay clear.

The state programme behind most of the barriers

The large public barriers are not installed by individual towns acting alone. They are part of a coordinated strategy in which the Quintana Roo Secretariat of Ecology and Environment (SEMA) supplies much of the material and the Mexican Navy (SEMAR) installs the barriers and runs collection at sea, alongside municipal beach crews and the hotel sector.

The programme has grown each year. At the start of 2026 the Navy reported 9,500 metres of barrier in use, after a 2025 season in which a record of about 92,783 tonnes of sargassum was collected.² In the last quarter of 2025 the state bought a further 7,500 metres for distribution across six coastal municipalities.³ The head of SEMA has stated that roughly 3,000 metres are lost each year to wear and weather, so a purchase of that size raises the working total by less than its length suggests.⁴ The state's target for 2026 is 16,030 metres; in late July, 9,450 metres were operating in Puerto Morelos, Playa del Carmen, Tulum and Mahahual.⁵ In early July the distribution was 2,310 metres in Puerto Morelos, 2,580 in Playa del Carmen, 2,295 in Tulum and 2,265 in Mahahual, with none recorded in Cancún.⁶ In September the Navy reported 13,230 metres of containment barrier deployed.⁷

Collection boats and the role of the barrier

A barrier does not dispose of sargassum. It holds the seaweed in place until it can be removed, and that work falls to specialised collection boats, known in Spanish as sargaceras. Research on the Mexican Caribbean found that sargassum held in a U-shaped barrier tends to begin decomposing and sinking after 24 to 48 hours, at which point it can be carried under the skirt and towards the beach, and that the collection vessels used in the region can remove between 15 and 45 tonnes an hour.¹ Without regular collection, a barrier therefore fails within a short time. The structures are also vulnerable to the sea itself: in July 2026 the head of SEMA acknowledged that strong waves had damaged part of the barriers installed in Cancún and Playa del Carmen, and said the state was working with suppliers on more resistant systems.⁵

In September 2026 the Navy reported a fleet of 11 coastal collection boats, each able to carry 20 tonnes, together with one ocean-going collection ship, two amphibious collectors and 18 smaller boats. Navy divers inspect the barrier anchors and their operating condition, and the Navy plans to add dynamic barriers designed to redirect the seaweed and concentrate it where the boats can collect it before it reaches the shore.⁷ The ocean-going ship, the Natans, entered service in 2021 with a hold capacity of up to 250 tonnes a day and works in deep water to collect seaweed before it reaches the coast.⁹ A second ocean-going ship, the Sargassum, was being fitted out in September 2026; the Navy states that it will raise daily collection capacity at sea from 627 to 1,227 tonnes.⁷ By September the federal government reported more than 123,400 tonnes collected in Quintana Roo in 2026, the largest volume recorded, against 92,782 tonnes in the whole of 2025.⁷

Collection is directed by forecasting. Navy specialists at the Oceanographic Institute of the Gulf and Caribbean track sargassum concentrations by satellite and calculate their likely paths and landing zones, and these calculations determine where barriers are placed and where boats and crews are sent.⁷ Barriers cannot be placed everywhere: the location, dimensions and shape of each one depend on the oceanographic and geomorphological characteristics of the site.¹

For deeper background on the containment effort as a whole, including collection boats, beach cleaning and the wider debate about reuse, see our companion piece: what can we do about sargassum?

Puerto Morelos

Installed by: The municipality of Puerto Morelos with the Mexican Navy (SEMAR), the Quintana Roo state government and local hotels.¹⁰
Where exactly: Off Puerto Morelos Centro. Municipal officials report 2,310 metres of barrier and describe it as protecting the 19-kilometre municipal coastline between Punta Brava and Punta Petempich.¹⁰ A barrier of that length can cover only a small part of that coast, and its exact extent has not been published; neighbouring stretches such as Puerto Morelos norte have been affected without the same protection.
How effective it seems: Variable. Local reports described its barrier as the most effective in the state in 2025,¹¹ but the beach is still regularly affected.

Puerto Morelos lies behind a fringing reef that encloses a shallow lagoon between about 550 and 1,500 metres wide; the reef crest breaks much of the incoming wave energy and protects the shore from storms.¹² Calmer water inside the reef makes a barrier easier to anchor and maintain, but the reef does not stop floating sargassum, which drifts over it and into the lagoon; researchers have documented repeated heavy accumulations on Puerto Morelos beaches since 2014,¹ and Puerto Morelos has historically been among the most affected municipalities.⁴ Municipal officials stated that the 2026 volume exceeded that of previous years despite the barrier.¹⁰ Puerto Morelos Centro is not free of sargassum, and a strong easterly push can overwhelm the system.

Playa del Carmen

Installed by: The municipality of Solidaridad with the Mexican Navy (SEMAR), plus separate barriers paid for by individual hotels.
Where exactly: The central town beaches, from Playa Fundadores beside the Cozumel ferry pier north to Punta Esmeralda. The municipality planned in March 2026 to double its barrier from 2.5 to 5 kilometres,¹¹ and in August reported five kilometres installed along this stretch with the support of the Navy.¹³ Separately, hoteliers of the Paradisus resort placed about one kilometre of barrier at Playa 88 and Punta Esmeralda.¹⁴ Other hotels that had begun installing their own containment by February 2026 include Coco Beach, Wyndham Alltra and Velas, and the municipality has studied a 400 to 500 metre extension south from the Fundadores pier towards Playacar, creating a designated point where the seaweed would be concentrated for collection.¹⁵
How effective it seems: Mixed, and highly dependent on the specific beach and the day.

The central section is one of the longest on the coast, but its results are inconsistent. Playa del Carmen faces the Cozumel channel, one of the main entry routes for sargassum, and at the volumes arriving in 2026 the barrier is only as effective as the collection keeping pace behind it. In May 2026 the leader of a local tourism cooperative described the Navy's barrier as insufficient for a port of the town's size.¹⁶ The barriers have also drawn criticism from local environmental activists, who argue that structures placed off nesting beaches such as Playa 72, Playa 88 and Punta Esmeralda could obstruct sea turtles coming ashore and trap hatchlings, and that an environmental impact study should have been required.^14,17 The municipal government has stated that its 2026 sea turtle protection programme guarantees the safety of the species.¹⁷

Tulum

Installed by: The Mexican Navy (SEMAR) with the Quintana Roo state government and the municipality of Tulum.
Where exactly: Previous installations have covered the public beaches of the Tulum National Park.¹⁸
How effective it seems: The hardest coastline to protect, and results reflect that.

Tulum is the most exposed of the major destinations. It sits at the southern entrance to the Cozumel channel, and its long beach faces the open sea without the wide sheltered lagoon found at Puerto Morelos. In 2026 the Navy reported that Tulum and Othón P. Blanco, the municipality that includes Mahahual, had received the most significant arrivals of moderate intensity of the year.⁷ In 2023 the Navy began installing barriers along 3.4 kilometres of the public beaches of the Tulum National Park,¹⁸ and containment has remained part of the protection system since.

An open, high-energy shoreline is precisely the environment in which floating barriers struggle most. Strong swells can push seaweed over the top of a boom or tear it from its anchors, and the volume arriving during a heavy landing can exceed what any barrier and collection fleet can process. Tulum's barriers help at the margins and on calmer days, and live conditions are the most reliable guide before committing to a specific beach.

Mahahual

Installed by: The Mexican Navy (SEMAR) with the Quintana Roo state government, in the municipality of Othón P. Blanco.
Where exactly: Off the town's coast, on the southern stretch fed by the Mahahual to Xcalak entry route.⁴
How effective it seems: Variable, depending on wind, waves and the size of each arrival.

Mahahual is among the first stretches of the Mexican coast to receive sargassum each season; in 2026 the state monitoring centre recorded the year's first arrivals at Xcalak and Mahahual.¹⁹ In January the commander of the Navy's 11th Naval Zone announced that more than 2,300 metres of barrier would be installed there under an emergency plan.²⁰ The barrier concentrates floating seaweed offshore so that collection boats can remove it, but its effectiveness varies with wind, waves and the intensity of each arrival. In August 2026 the Central and Southern Quintana Roo Hotel Association agreed with the federal and state governments to install a further 1,750 metres, covering northern and southern sectors of Mahahual that had remained unprotected, together with shallow-draught collection boats.²¹

Cancún

Installed by: The Quintana Roo state government (SEMA) with the Mexican Navy (SEMAR) and the municipality of Benito Juárez.
Where exactly: Playa del Niño in Puerto Juárez, the site of the most recent barrier in the municipality; a project at Playa Coral remains on hold.²²
How effective it seems: Too recent to assess.

Cancún has been slow to receive barriers. In May 2026 the head of SEMA explained that marine currents make conventional barrier installation difficult in Cancún, and that the state was analysing between one and 1.5 kilometres of barrier at Playa Coral, a public beach with high levels of arrival.²³ The same month SEMA confirmed that at least 400 metres would be installed on Cancún's beaches following viability studies with the Navy and the National Autonomous University of Mexico (UNAM), with the exact site to be chosen by the Navy.⁴ By mid-July a barrier had been placed at Playa del Niño, while the Playa Coral project remained on hold.²²

Private hotel barriers

Installed by: Individual resorts, at their own expense.
Where exactly: In front of individual resorts outside the main municipal lines, including the Paradisus resort in northern Playa del Carmen¹⁴ a 1,050-metre barrier at Maroma,²⁴ and a barrier bought by the residents' association of Puerto Aventuras.²⁵
How effective they seem: Useful in calm conditions, unreliable in very poor conditions.

Separate from the public programme, a number of resorts have installed their own barriers. At Maroma, Grupo Lomas installed a 1,050-metre barrier in 42 sections along the coast, anchored into rock with stainless-steel pins, to support beach maintenance and reduce the seaweed reaching the shore.²⁴ At Puerto Aventuras, the residents' association approved a 6.6-million-peso project in February 2026 for a main barrier of about 900 metres across Bahía de Fátima and two smaller barriers in front of the Club de Yates and Kantenah coves.²⁵ The barrier was manufactured abroad, and in July its delivery was held up by customs requirements.²⁶ Private barriers can keep a resort's swimming area usable in light to moderate conditions, but they cover a short length of shoreline on an open, east-facing coast, and a strong onshore wind will still push seaweed through or around them.

The state government coordinates its strategy with the hotel sector,²⁷ and the division between hotel and government barriers is becoming less distinct as resorts add their own containment alongside the public lines.

Implications for travellers

Where a barrier exists, it improves the odds of clear water without guaranteeing it. Conditions on the beach depend heavily on coordination between the barrier and the collection effort behind it: how quickly the Navy's collection boats empty the seaweed held against the boom, how well satellite forecasts direct those boats to the right stretch of coast, and how promptly municipal and hotel crews clear what still reaches the sand. Playa del Carmen, Tulum and Puerto Morelos can be heavily affected, particularly between May and August, and during those periods their barriers are not sufficient on their own to keep the beaches clear; the state and the Navy are working to strengthen and extend the containment there, but for now all three call for flexible plans and close attention to the forecast. Independently of barriers, the islands and lagoons covered in our guide to destinations that avoid sargassum are protected by geography.

References

Figures and findings belong to the agencies, reporters and authors cited below.

1. Chávez, V., Uribe-Martínez, A., Cuevas, E., et al. (2020). Massive influx of pelagic Sargassum spp. on the coasts of the Mexican Caribbean 2014–2020: challenges and opportunities. Water, 12(10), 2908.
2. Secretaría de Marina, Gobierno de México (January 2026). Marina, en coordinación con el Gobierno del estado de Quintana Roo, continúa la contención del sargazo. Press release.
3. Gobierno de Quintana Roo, Coordinación General de Comunicación (27 February 2026). Gobierno de Quintana Roo intensifica acciones para contener el sargazo en los litorales.
4. Novedades Quintana Roo (5 May 2026). Confirman instalación de barreras anti sargazo en Cancún.
5. Por Esto (24 July 2026). Sargazo en Quintana Roo: prevén un recale superior a las 92 mil toneladas este año.
6. 24 Horas Quintana Roo (7 July 2026). Sargazo en Quintana Roo 2026: van casi 80 mil toneladas.
7. Excélsior (8 September 2026). Semar refuerza estrategia contra el sargazo en el Caribe mexicano.
8. Infobae (4 May 2026). Marina anuncia la limpieza de 28 mil toneladas de sargazo en lo que va del 2026.
9. Animal Político (27 July 2021). A mitad de temporada, Marina recolecta 26 mil toneladas de sargazo.
10. Heraldo de México Quintana Roo (7 May 2026). Trabajo constante mantiene a raya el sargazo en Puerto Morelos.
11. El Universal (11 March 2026). Sargazo llega antes al Caribe mexicano.
12. Franklin, G. L., Torres-Freyermuth, A., Medellín, G., et al. (2018). The role of the reef–dune system in coastal protection in Puerto Morelos (Mexico). Natural Hazards and Earth System Sciences, 18, 1247–1260.
13. La Jornada (4 August 2026). En Playa del Carmen instalan cinco kilómetros de barrera anti sargazo para preservar el turismo.
14. Por Esto (15 April 2026). Barreras en el mar en Playa del Carmen son un riesgo letal para las tortugas marinas.
15. Reportur (27 February 2026). Sargazo disparado en Playa del Carmen activa planes de hoteles.
16. Proceso (1 May 2026). Barrera de la Marina no puede contener el intenso arribo de sargazo en Playa del Carmen.
17. Por Esto (12 May 2026). Sargazo, perros y barreras amenazan anidación de tortugas en Playa del Carmen, advierten ambientalistas.
18. La Jornada Maya (2023). Inicia instalación de barreras antisargazo en las costas de Tulum.
19. La Jornada (9 January 2026). Se adelanta arribazón de sargazo en costas de Quintana Roo.
20. La Jornada (12 January 2026). Plan emergente en marcha tras llegada anticipada de sargazo en Mahahual.
21. Reportur (4 August 2026). Barrera antisargazo en Mahahual: hoteleros acuerdan instalar 1,750 m.
22. 24 Horas Quintana Roo (14 July 2026). Barrera antisargazo: descartan instalarla en toda la costa.
23. La Jornada Maya (3 May 2026). Quintana Roo intensifica labores de contención del arribo de sargazo.
24. Novedades Quintana Roo (28 May 2026). Optan por barreras privadas ante recale masivo de sargazo en la Riviera.
25. Noticaribe (27 April 2026). Inician instalación de barrera antisargazo en marina de Puerto Aventuras.
26. Noticaribe (1 July 2026). Barrera antisargazo adquirida por colonos de Puerto Aventuras pendiente de arribar a causa de procedimientos aduanales.
27. Heraldo de México Quintana Roo (24 March 2026). Refuerzan estrategia contra el sargazo en Quintana Roo previo a Semana Santa.

Barrier lengths and locations change through the year as material is added, moved and replaced. Some links to hotels and activities are affiliate links; if you book through them, Sargazo Watch may earn a small commission at no additional cost to you.