Sargassum in St Barths

sargassum is st barths

In 2023, sargassum has been making headlines in the US due to the significant threat it poses to beaches in Florida and Mexico. Seasonal sargassum blooms have been growing at an alarming rate in the tropical Atlantic for over a decade, with this year’s bloom already being staggeringly large. Spanning roughly 5,000 miles, this massive seaweed bloom can even be seen from space, floating between the Gulf of Mexico and the shores of West Africa. While it is generally harmless and can even be beneficial in open water, ocean currents are pushing sargassum west, causing hundreds of tons of seaweed to wash up on beaches across the Caribbean and Gulf of Mexico. There, it can damage coastal ecosystems, choke corals, and diminish water and air quality as it decomposes.

Scientists have reported that this bloom is one of the largest on record, raising concerns that seaweed invasions on beaches in the coming weeks and months could be particularly severe. In addition to environmental damage, sargassum can cause disruptions to critical infrastructure, like intake valves for power plants or desalination plants, and hinder navigation for marinas and boats. It can also have health impacts, as decomposing sargassum releases hydrogen sulfide, which can cause respiratory problems for tourists and residents in the affected areas. The economic repercussions are also significant, as sargassum invasions can negatively impact tourism and require expensive clean-up efforts.

II. Sargassum in St Barths: Overview and Risks for 2023

St Barths, a popular tourist destination in the Caribbean, has been facing the challenge of sargassum for several years. As a small island with picturesque beaches and crystal-clear waters, the presence of sargassum can have significant consequences for tourism and the local ecosystem. Although the 2023 sargassum bloom is making headlines in the US, it is essential for travelers to St Barths to be aware of the situation and understand the potential risks associated with sargassum for the year 2023.

A. General Situation in St Barths

In recent years, St Barths has been grappling with periodic influxes of sargassum washing up on its shores. The island’s authorities and local communities have been working diligently to address this issue and minimize its impact on the environment and tourism industry. While sargassum presence varies from year to year and beach to beach, some areas of St Barths are more prone to sargassum accumulation than others. In general, the eastern and southeastern coastlines tend to be more affected due to the prevailing ocean currents.

B. Risks for 2023

Given the severity of the sargassum bloom in the Atlantic in 2023, there is a possibility that St Barths may experience a more significant influx of sargassum on its beaches this year. The risks associated with sargassum in St Barths for 2023 include:

  1. Environmental Impacts: Large quantities of sargassum on the beaches can smother marine life, choke corals, and disrupt the local ecosystem. Decomposing somposing sargassum can also release unpleasant odors and decrease water and air quality, affecting both marine life and human health.
  1. Tourism: The presence of sargassum on St Barths’ beaches can negatively impact the island’s tourism industry, as tourists may be deterred by the sight and smell of rotting seaweed. This can result in reduced revenue for local businesses that rely on tourism.
  2. Beach Clean-up Efforts: Increased sargassum accumulation will require more frequent and extensive clean-up efforts, which can be both time-consuming and costly for the local government and community.
  3. Potential Health Issues: As sargassum decomposes, it releases hydrogen sulfide, which can cause respiratory problems for people in the vicinity. While this is not a widespread issue, individuals with pre-existing respiratory conditions should be cautious when visiting areas with large amounts of decomposing sargassum.

Despite these risks, it is essential to note that St Barths has been managing the sargassum situation for years, and the island’s authorities are continuously implementing measures to address the issue. Travelers to St Barths can stay informed about the sargassum situation and choose their beach destinations accordingly. Overall, while sargassum may present some challenges, it should not deter visitors from enjoying the beauty and charm of St Barths.

III. Understanding Sargassum

  1. What is sargassum?

Sargassum is a genus of large, free-floating brown seaweed (macroalgae) that primarily inhabits the tropical and subtropical regions of the Atlantic Ocean. It is known for its distinctive air bladders that help it stay afloat and spread across vast distances. The two most common species associated with large blooms are Sargassum natans and Sargassum fluitans.

  1. The Sargasso Sea

The Sargasso Sea, located in the North Atlantic, is the only sea without a land boundary. It is named after the abundant sargassum found in its waters, which serves as a unique ecosystem for various marine species. This area is a crucial breeding and nursery ground for many fish, sea turtles, and marine mammals. Additionally, the floating sargassum provides a habitat for various birds, crabs, and other small marine animals.

  1. Sargassum blooms

Sargassum blooms are natural occurrences in which large masses of seaweed accumulate in a specific area, usually due to a combination of factors such as nutrient availability, ocean currents, and water temperature. In recent years, these blooms have become more extensive and frequent, impacting the Caribbean and Gulf of Mexico regions.

  1. Factors contributing to sargassum growth

Several factors have been identified as contributing to the accelerated growth of sargassum in recent years, including:

While sargassum may appear to be a simple seaweed, it is actually a highly complex and fascinating organism. It is a type of floating brown algae that is known for its unique ability to provide habitat and shelter for a wide range of marine life, including sea turtles, crabs, and shrimp.

Sargassum can grow in large, dense mats that stretch across the ocean’s surface, and it is found in several locations around the world, including the Sargasso Sea in the North Atlantic Ocean, and the tropical Atlantic, where it is currently causing problems for Caribbean beaches.

The seaweed has been around for millions of years, and while it is generally harmless in the open ocean, it can become a nuisance when it washes up on beaches in large quantities. When sargassum rots, it can release a strong odor of hydrogen sulfide, which can cause respiratory problems for people and animals in the vicinity. Additionally, the decaying seaweed can attract insects, such as sand flies, which can be a nuisance to beachgoers.

Despite its drawbacks, sargassum has many beneficial properties. It is an important carbon sink, which means that it helps to absorb and store carbon dioxide from the atmosphere. It also provides habitat for a wide range of marine life, and some species of sargassum are used for food, medicine, and other purposes.

Overall, while sargassum may be causing problems for beaches in St Barths and other parts of the Caribbean, it is important to understand the many complex roles that it plays in marine ecosystems around the world. By taking steps to manage and mitigate the impacts of sargassum, we can help to protect both our beaches and the natural world around us.

One of the factors contributing to sargassum growth is climate change. Rising temperatures and increasing levels of carbon dioxide in the atmosphere can create conditions that favor the growth of sargassum. In addition, changes in ocean currents, nutrient availability, and water chemistry can also influence the proliferation of this seaweed.

Human activities also play a role. The use of fertilizers and other agricultural practices can lead to an excess of nutrients in nearby bodies of water, providing a food source for sargassum. Deforestation and land-use changes can also contribute to nutrient runoff and sedimentation in rivers and coastal areas.

Furthermore, the large-scale removal of seaweed-eating fish and sea turtles from marine ecosystems can result in an imbalance that favors the growth of sargassum. This can be seen in the Sargasso Sea, where populations of green sea turtles have been severely depleted due to hunting and accidental capture in fishing gear.

Understanding these factors is critical to developing effective strategies for managing sargassum blooms and protecting marine ecosystems. By reducing nutrient inputs, promoting the restoration of key marine species, and mitigating the impacts of climate change, we can work to prevent the overgrowth of sargassum and ensure the health and vitality of our oceans for generations to com

IV. St Barths’ Actions Against Sargassum

St Barths has taken a proactive approach to address the sargassum issue. The local government has created a dedicated committee for combating sargassum, which collaborates with national and regional organizations. This committee works on several fronts, including monitoring sargassum influxes, investing in cleanup efforts, and participating in research and prevention initiatives.

Public initiatives

One of the main actions taken by the local government is investing in cleanup efforts. Almost every day, when there is sargassum on the beach, the local government pays for its removal, particularly in areas like Anse des Cayes and Marigot, which can be most affected. The cleanup efforts ensure that visitors can still enjoy the beaches without having to deal with the nuisance of rotting seaweed.

In addition to the cleanup efforts, St Barths has participated in research and prevention initiatives to address the sargassum problem. For example, in 2019, St Barths hosted a conference on sargassum, which brought together local and international experts to discuss the problem and potential solutions. The conference resulted in the creation of the Sargasse Project, which seeks to transform sargassum into a valuable resource.

Private Initiatives

The Sargasse Project is an initiative that aims to valorize sargassum by transforming it into a useful material. Pierre-Antoine Guibout, the owner of the Cygne Noir brand, started this project after recognizing the impact of sargassum on the beaches of St Barths. His initial idea was to transform the seaweed into shoe polish, but it was not feasible due to chemical incompatibility. Eventually, he found a way to use the seaweed in packaging, and with the help of the CEVA laboratory, he was able to certify his creation.

The Sargasse Project aims to establish a factory in St Barths to process the sargassum that is collected from the island’s beaches. The factory will transform the seaweed into plates of approximately 250 kg each, which can be used as raw material for the production of environmentally friendly materials. The project also seeks to duplicate the same type of production unit on other Caribbean islands, such as Guadeloupe and Martinique, where sargassum invasions have also been a problem.

Overall, St Barths is taking proactive steps to address the sargassum issue. The local government’s dedicated committee for combating sargassum, the cleanup efforts, and participation in research and prevention initiatives such as the Sargasse Project demonstrate the island’s commitment to tackling this problem. While sargassum may still be a nuisance for visitors, they can be reassured that St Barths is taking actions to mitigate its impact.


The best of tips on how to get to St Barths, where to dine, the beaches we prefer,  when to pick a luxury hotel or a private villa, and more tips to enjoy the island at its best.