oceans
Humans may start mining the deep sea despite limited knowledge
A new leader at the International Seabed Authority could pave the way for deep-sea mining, raising concerns about its environmental impact.
In short:
- The International Seabed Authority (ISA) governs over half of the world’s ocean floor and is debating whether to allow deep-sea mining.
- The newly elected ISA secretary-general, Leticia Carvalho, may oversee the first mining operations despite scientific concerns about environmental harm.
- Recent studies suggest deep-sea mining could have irreversible ecological consequences, threatening unique marine life.
Key quote:
“The environmental implications will be significant. They would be irreversible on human timescales.”
— Pradeep Singh, ocean governance expert at the Research Institute for Sustainability
Why this matters:
Mining the deep sea could damage ecosystems that are crucial to ocean health, with impacts that may last for centuries. As the ISA considers approving mining, global debate intensifies over whether the potential economic benefits outweigh the environmental risks.
Related: UN debates deep sea mining code amid global concerns
Oceans under threat from heating, deoxygenation, and acidification
The world's oceans are experiencing unprecedented stress from extreme heat, oxygen loss, and acidification due to human activities like burning fossil fuels and deforestation.
In short:
- A fifth of the world’s ocean surface is highly susceptible to these combined threats.
- Extreme conditions in the upper 300 meters of affected ocean areas now last three times longer and are six times more intense compared to the 1960s.
- The compounding threats particularly impact the tropics and the north Pacific.
Key quote:
“Oceans aren’t just a nice backdrop for your selfies in summer, we rely upon them for our lives.”
— Andrea Dutton, geologist and climate scientist at the University of Wisconsin–Madison
Why this matters:
The ocean's health is critical for maintaining global climate stability and supporting marine life. The increasing frequency and intensity of these extreme conditions threaten marine ecosystems and the livelihoods dependent on them.
Ocean temperatures hit record levels, impacting marine life
The world's oceans have set daily temperature records throughout the past year due to climate change.
Matt McGrath, Mark Poynting, and Justin Rowlatt report for BBC News.
In short:
- Ocean surface temperatures have consistently exceeded long-term averages, with recent peaks causing extensive coral bleaching.
- The elevated temperatures are largely driven by human-produced greenhouse gases, though the El Niño phenomenon has intensified the effects.
- Marine species are experiencing dramatic shifts in their environments, impacting biodiversity and ecological balance.
Key quote:
"The fact that all this heat is going into the ocean, and it's warming in some respects even more rapidly than we thought it would, is a cause for great concern."
— Prof Mike Meredith, British Antarctic Survey
Why this matters:
For marine life, the increase in water temperature can disrupt species' migration patterns, breeding cycles, and food sources. Coral reefs, often referred to as the rainforests of the sea due to their rich biodiversity, are particularly vulnerable. They suffer from bleaching events that strip them of their color and life as the algae—vital for their survival—are expelled.
From poisoning to skin diseases: multiple effects of sargassum on health
Sargassum health problems plague Caribbean French islands despite millions spent.
This is a republishing collaboration with Centro de Periodismo Investigativo, where this originally published. See the full series, Caribbean People at Risk from Sargassum Invasion.
In the quiet seaside village of Capesterre on Marie-Galante island in Guadeloupe on April 18, 2023, the air-quality monitoring institute Gwad’Air issued a “red alert” to warn people away from coastal areas.
The culprit was sargassum. After washing ashore for days, the floating seaweed was emitting a dangerous level of hydrogen sulfide gas as it rotted on the beach.
To read a version of this story in Spanish click here. Haz clic aquí para leer este reportaje en español.
The problem was not new for residents of Marie-Galante, a sleepy agricultural island of 11,000 inhabitants that is part of Guadeloupe’s biosphere reserve.
Since the first mass strandings more than ten years ago, rotting sargassum has frequently plagued residents and tourists and forced several businesses and restaurants to close their doors for months at a time.
Among the struggling proprietors are sisters Marie-Louise and Lyselène Bade, who recently shuttered their small hotel Le Soleil Levant.
Marie-Louise Bade is the owner of the small hotel Le Soleil Levant, which had to close due to the sargassum invasion in Guadeloupe.
Credit: Marie-Louise Bade
Though they still operate a bakery and grocery store they inherited from their mother, Marie-Louise said a Gwad’Air technician recently asked her a worrying question: “How do you manage to stay here?”
She often wonders the same thing.
“You know, I love wearing costume jewelry, but now I can’t keep it on my skin for more than a quarter of an hour. They oxidize and make my skin itch. When you see what it does to electrical equipment and metal, you wonder what it does inside your body, to your lungs,” she said.
According to Marie-Louise Bade, since sargassum has increased in Guadeloupe, metal furniture and artifacts have begun to corrode more quickly.
Credit: Olivia Losbar/RCI Guadeloupe
Thanks to recent research carried out in the French Caribbean — much of which has struggled with similar problems as Marie-Galante — scientists can now better answer that question.
They paint a bleak picture. Their studies suggest that the hydrogen sulfide and ammonia gasses released by rotting sargassum can endanger pregnant women, exacerbate respiratory issues like asthma, and cause headaches and memory loss, among other serious health problems.
But this knowledge has not been enough to protect Bade and many other Guadeloupe residents.
Even as the French Caribbean has emerged as a regional leader in the fight against sargassum, researchers such as Martinique-based doctor Dabor Resiere have said response efforts there have fallen far short.
As a result, many residents regularly face dangerous health risks — and the French government has turned to the world stage to call for an international response to address sargassum as a global problem.
‘Airborne poisoning outbreak’
By the time 2018 brought a record sargassum influx to Caribbean shorelines, the health effects of the rotting seaweed had become much better known. In December of that year, a group of sargassum researchers in Martinique issued a stark warning.
In a letter published in The Lancet medical journal, they noted that doctors in Martinique and Guadeloupe — French islands with a combined population of nearly 800,000 — had recently recorded more than 11,000 cases of acute sargassum toxicity during an eight-month period. Among them were three cases admitted to intensive care.
“To mitigate this emerging airborne poisoning outbreak, the French government has already promised €10 million [US $10,835,600] to supply equipment that can be used to remove the seaweed within 48 hours, to monitor hydrogen sulfide concentrations on the affected shores, to train doctors, and to assign experts in toxicology in affected areas,” wrote Resiere and 10 other researchers based in Martinique and France.
“Despite this commendable first effort by the French government, a mitigation plan to address this enigmatic sargassum invasion should urgently be discussed at an international level to boost marine research, pool resources, and consolidate local political priorities,” Resiere said.
The French government — which for decades has struggled with algae washing ashore on its European coasts — has launched two national sargassum plans funded with about $26 million for 2018-2022 and about $40 million for 2022-2026. Millions more were spent by local authorities in sargassum collection operations and investment in dedicated equipment.
“You know, I love wearing costume jewelry, but now I can’t keep it on my skin for more than a quarter of an hour. They oxidize and make my skin itch." - Marie-Louise Bade, owner of the small hotel Le Soleil Levant
As a result, the French islands of Guadeloupe, Martinique, Saint Martin and Saint Barthelemy have launched some of the most extensive response efforts in the Caribbean in recent years. Besides the ongoing research, these efforts have included air-quality-monitoring programs, clean-up initiatives, and one of the rare national response strategies that has been officially adopted by the government.
In 2019, Guadeloupe also hosted the first International Sargassum Conference, where the Guadeloupe Region — in partnership with the French government, the French National Research Agency and two Brazilian agencies — launched a call for projects with financial support from the European Union and other sources.
This effort ultimately funded 12 projects — the results of which were presented on Feb. 28, 2024 — as part of the National Sargassum Prevention and Control Plan. Besides probing the algae cycle and the environmental effects of sargassum, these projects have also investigated health impacts.
One of the outcomes, the SargaCare project, led to a July 2022 study on more than 3,000 pregnant women on Martinique, which reported finding evidence of a higher risk of potentially fatal preeclampsia in expectant mothers exposed to sargassum fumes.
A later SargaCare studysuggested that prolonged exposure to the fumes increases the risk of patients developing sleep apnea.
‘The situation remained unchanged’
But despite this work, health researchers have warned that response efforts have not kept pace with the problem in the French Caribbean or the wider region.
More than four years after their 2018 warning in The Lancet, Dr. Resiere and seven colleagues upped the ante in a March 2023 letter published in the Journal of Global Health.
In Guadeloupe and Martinique, they wrote, “the situation remained unchanged. Despite the French government’s plans to tackle the sargassum problem, these toxic algae are continuing to inundate the coasts of Martinique, Guadeloupe, and French Guiana in ever-greater volumes.”
The Covid-19 pandemic, they stated, was partially to blame for the problem because it had sucked up health resources. But they also noted the absence of a coordinated regional health response and warned that Caribbean governments eager to jumpstart their post-pandemic tourism economies may be inclined to downplay the sargassum problem.
“The public continues to be adversely affected, some have sold their dream houses which are becoming unlivable, some have abandoned their schools and workplaces for lack of a solution to this scourge,” the researchers wrote. “It is urgent to come to the aid of these families who, in addition to the health consequences due to the significant emanations of hydrogen sulfide, have to bear the material consequences, being often forced to replace all their household appliances or the metal parts of their houses.”
2023 season
By the time the researchers’ letter was published in March 2023, a new sargassum season was already causing health problems across the French Caribbean.
In late January 2023, a 59-year-old woman was treated by emergency services for acute toxicity after taking part in a sargassum clean-up on Tartane beach in Trinité, Martinique.
On March 2, the Martinique municipality of Le Robert partially closed the Four à Chaux school due to high exposure to gas released by sargassum.
Boats float in sargassum off Batelière Beach in Schoelcher, Martinique, on Sept. 12, 2023.
Credit: Jacques Dijon/RCI Guadeloupe
And when the air pollution alert was triggered in Guadeloupe’s Saint-François lagoon area on Sept. 15, people were asked to move away from a populated marina area that hosts hotels, restaurants and tourism businesses offering water activities.
Marie-Galante
Back in Marie-Galante, Marie-Louise Bade continued to struggle as well. Bade, who goes by “Malou,” operates multiple businesses on her island, where the economy is powered by tourism, fishing, sugarcane and banana crops, and a rum distillery.
“For 11 years, I’ve had to put up with this,” Bade said. “For 11 years, every time I open my doors, I think, ‘My God, what other appliance is going to break down this morning?’ No matter how much we repair, clean, the walls turn gray. Algae eats away at all the plumbing. … So everything is destroyed and there are leaks all the time.”
Tourists, she said, stopped coming.
“I can’t rent out the rooms anymore,” she said. “People open the windows, they have a view of the sargassum. There’s the smell. And on the walls, the pipes, the air-conditioning: Everything turns black.”
A great amount of sargassum saturated the coastline of Batelière, Martinique, on September 12, 2023.
Credit: Jacques Dijon/RCI Guadeloupe
Her health has suffered as well.
Bade described continuous itching, small pimples appearing on her skin, vision issues, and respiratory problems that now force her to take asthma medication.
Various governmental efforts have not provided relief in her day-to-day life, she said. About two years ago, for example, the Guadeloupe regional health agency distributed questionnaires for about a month. But since then, she said, no follow-up action has been taken to her knowledge.
The businesswoman said the town doctor regularly monitors the effects of sargassum on the population’s health, and he encourages her to consult him every three months.
Last year, residents got a brief respite when booms were installed offshore in August in hopes of preventing the seaweed from reaching the beach.
For a while, the solution worked, according to the town’s mayor, Jean-Claude Maes. Residents started walking along the coast again as they hadn’t done for years, and a few entrepreneurs decided to set up new businesses, Maes said.
But the respite was short-lived: The booms were swept away last October by swells caused by Hurricane Tammy. Plans to reinstall them by December still have not come to fruition.
An anti-sargassum boom was installed last year to protect La Feuillère Beach in Capesterre de Marie-Galante, but it was damaged by Hurricane Tammy in October. On Dec. 1, 2023, it was lying on the shoreline awaiting reinstallation.
Credit: Olivia Losbar/RCI Guadeloupe
Though such responsibilities normally fall to towns and cities, the French government has decided to bear 80% of the financial cost of combating sargassum. But the mayor said that funding was slow in coming last year.
‘Irritation and anxiety’
While residents suffer, research continues. Professor Dabor Resiere, a sargassum researcher and department head at Martinique University Hospital, said previous studies have focused largely on the effects of acute toxicity caused by high levels of sargassum gasses.
But there is a dearth of information on chronic toxicity at lower doses, he said. To learn more, the professor and his team have been visiting patients in the field as part of a Martinique University Hospital monitoring program they plan to export soon to Guadeloupe, St. Lucia and other islands.
“We don’t know about the average resident who lives near a stranding site, who receives a small amount of [exposure to sargassum gas] every day,” said Resiere. “We can see that the majority of these patients continue to have trouble sleeping, continue to have generalized fatigue, continue to have conjunctivitis, irritation and anxiety. This anxiety, this depressive syndrome: All these symptoms we observe in patients. But now we need to demonstrate it scientifically.”
Other research is continuing as well. After the results of the 2019 call for projects were presented this February, the Guadeloupe Region and its partners launched a new call for projects. This round will continue studying health impacts, as well as addressing other topics including sargassum’s effects on marine ecosystems and the hydrodynamic conditions that affect blooms.
But in Marie-Galante, Bade and her sister have more immediate concerns.
Currently, the metal roof of their businesses leaks because of holes they blame on corrosion caused by the sargassum gasses. But they are reluctant to invest in repairs as long as they are faced with continued uncertainty.
Despite the risks, they have no plans to leave. For Bade, it is inconceivable to close the business bequeathed to her by her mother, in which she and her sister grew up.
“What would the town be without a bakery?” she asked.
This investigation is the result of a fellowship awarded by the Center for Investigative Journalism’s Training Institute and was made possible in part with the support of Open Society Foundations.
Desde intoxicaciones hasta enfermedades de la piel: múltiples los efectos del sargazo en la salud
Los problemas de salud relacionados con el sargazo afectan a las islas francesas del Caribe a pesar de los millones invertidos en atender la amenaza.
Este artículo fue publicado originalmente por el Centro de Periodismo Investigativo. Hace parte de la serie de reportajes "Caribeños en riesgo por la invasión del sargazo".
En el tranquilo pueblo costero de Capesterre, en la isla Marie-Galante de Guadalupe, el 18 de abril de 2023, la Asociación de Monitoreo de Calidad del Aire, Gwad’Air, emitió una “alerta roja” para advertir a la gente que se alejara de las zonas costeras.
La causa: el sargazo. Después de haber llegado durante días a la costa, esas algas flotantes se descomponían en la playa y emitían un nivel peligroso de ácido sulfhídrico, un gas cuyo olor a huevos podridos puede afectar la salud de quienes lo aspiran por periodos extensos.
El problema no era nuevo para los residentes de Marie-Galante, una tranquila isla agrícola de 11,000 habitantes que forma parte de la reserva de la biosfera de Guadalupe.
Haz clic aquí para leer este reportaje en inglés. To read a version of this story in English click here.
Desde las primeras acumulaciones masivas ocurridas hace más de diez años, la descomposición del sargazo ha afectado con frecuencia a los residentes y turistas, y ha obligado a varios negocios y restaurantes a cerrar sus puertas por meses.
Entre esos propietarios que luchan por sobrevivir están las hermanas Marie-Louise y Lyselène Bade, quienes recientemente cerraron su pequeño hotel Le Soleil Levant.
New methods aim to enhance the ocean's ability to capture carbon dioxide
Researchers and startups are developing innovative marine carbon dioxide removal techniques to increase the ocean's carbon absorption capabilities. However, doubts about its potential impacts remain.
In short:
- The ocean absorbs 30% of global CO2 emissions. Private companies, venture capitalists and governments are developing new methods to "enhance" this capacity.
- Startups like Running Tide are experimenting with sinking biomass into the ocean to store carbon, leveraging the ocean's natural capacity to do so. Others are experimenting with algae and kelp or pumping seawater through electrodialysis filtering systems.
- Scientists express concerns about the unknown effects and efficacy of marine carbon dioxide removal methods on global warming and marine ecosystems.
Key quote:
“We’re intervening in the natural world, which means we need to be very careful about what we do.”
— Kristinn Hróbjartsson, general manager of Running Tide in Iceland.
Why this matters:
The Intergovernmental Panel on Climate Change (IPCC) has made it clear that carbon sequestration needs to be part of the strategies to limit global warming to between 1.5 and 2 degrees Celsius. Enhanced marine carbon sequestration could play a role in meeting the threshold.
John Harte, a senior researcher at UC Berkeley's famed Energy and Resources Group, has spent a lifetime looking at the "smoke and mirrors" behind geo-engineering and carbon sequestration.
After 13 years, no end in sight for Caribbean sargassum invasion
Thousands of people were hurt by sargassum blooms last year in the Caribbean.
This is a republishing collaboration with Centro de Periodismo Investigativo, where this originally published. See the full series, Caribbean People at Risk from Sargassum Invasion.
Schools evacuated due to toxic gas. Smelly tap water at home. Tourist operators and fishers struggling to stay in business. Job losses. Power outages affecting tens of thousands of people at a time. Dangerous health problems. Even lives lost.
To read a version of this story in Spanish click here. Haz clic aquí para leer este reportaje en español.
Such crises were some of the consequences of sargassum in the islands of the Caribbean in 2023, and they have become common in the region since 2011 when massive blooms began inundating the shorelines in the spring and summer months.
On April 18, 2023 in Guadeloupe, the air-quality monitoring agency Gwad’Air advised vulnerable people to leave some areas because of toxic levels of gas produced by sargassum. Six weeks later, about 600 miles to the northwest, sargassum blocked an intake pipe at an electricity plant at Punta Catalina in the Dominican Republic. One of the facility’s units was forced to temporarily shut down, and a 20-year-old diver named Elías Poling later drowned while trying to fix the problem.
A team removes sargassum at the facilities of the Punta Catalina Thermoelectric Power Plant in the Dominican Republic in 2023.
Credit: Punta Catalina Thermoelectric Power Plant
In Jamaica, during the months of July and August, fishers found themselves struggling through one more season as floating sargassum blocked their small boats and diminished their catch.
“Sometimes, the boats can’t even come into the creek,” said Jamaican fisherman Richard Osbourne. “It blocks the whole channel.”
In the British Virgin Islands (BVI), most of Virgin Gorda’s 4,000 residents had to deal with sporadic water shutoffs and odorous tap water for weeks after sargassum was sucked into their main desalination plant last August.
And in Puerto Rico, a highly unusual late-season influx inundated the beaches of the Aguadilla area for the first time, leaving residents like Christian Natal and many others out of work for a week when it shut down businesses including the jet ski rental company that employs him.
Christian Natal works at a water vehicle rental company in the “Crash Boat” beach in the municipality of Aguadilla that had to close last year due to the unusual arrival of sargassum to the northwest of Puerto Rico.
Credit: Gabriel López Albarrán/Centro de Periodismo Investigativo
These victims are among thousands of people hurt by sargassum blooms last year alone in the Caribbean, where about 70% of the population of around 44 million lives near the coast, according to the World Bank.
Scientists blame the explosive growth of the seaweed on global pollution, climate change, and other international problems that Caribbean islands did little to cause and lack the political power to resolve.
“Seaweed must be seen as an impact of global warming, with the opening up of the right to compensation on the grounds that we are small, vulnerable islands,” said Sylvie Gustave dit Duflo, the vice-president of the Guadeloupe Region in charge of environmental issues and president of the French Biodiversity Office.
She added that the countries of the Caribbean Community (CARICOM) — which include 15 member states and five associate members that are territories or colonies — recorded economic losses of about $102 million due to sargassum in 2022 alone.
“These figures do not take into account the losses recorded in all the other Caribbean countries, including the French islands,” she said. Nor do they take into account yearly costs of beach cleaning estimated to be as high as an additional $210 million.
Ezekiel Bobb, who lives near the ocean at Handsome Bay, Virgin Gorda, has suffered from the odor of decaying sargassum in recent years. He has tried to do his part by using it for fertilizer in his garden, but he is unable to make much dent in the massive amounts that wash ashore.
Credit: Freeman Rogers/The BVI Beacon
Gustave dit Duflo and other experts say the global problem requires a global response. But so far, the Caribbean has failed to coordinate even a region-wide strategy, and the international community has largely turned a blind eye. National-level responses — which in most Caribbean countries include a draft management strategy that hasn’t been officially adopted or adequately funded — have done little to take up the slack.
Most sargassum influxes are predictable, and the worst impacts are often preventable. But again and again, Caribbean governments have waited to react until the crisis stage. And even then, the responses have often focused on protecting the tourism industry while other groups, such as local communities or fishers, are left behind.
As a result, residents’ health, livelihood and natural environment have been endangered, and hundreds of millions of dollars have been spent on reactive emergency responses that experts say could have been better spent on prevention, planning and mitigation.
At the Conference of the Parties to the UN Framework Convention on Climate Change (COP28) last December in Dubai, Gustave dit Duflo helped unveil a French proposal for the sort of international response she says is urgently needed. It includes forming a global coalition to better understand the problem, ensuring that sargassum is on the agenda of major international forums, and continuing previous work in partnership with the European Union, among other measures.
But to implement the proposal, governments in the Caribbean and further abroad will have to overcome hurdles that have previously stymied cooperation, including political and legislative differences, funding shortages, and debate about whether to prioritize health, the environment, the economy, or other areas.
In the meantime, sargassum has already started to arrive on the Caribbean’s shores once again. And once again, the region is not ready.
The ‘Great Atlantic Sargassum Belt’
By April 8, 2024 (above), sargassum was once again washing ashore near the desalination plant at Handsome Bay, Virgin Gorda, but the promised protective boom had not been installed.
Sargassum is not a bad thing in itself. Nor is it new to the Caribbean, where it has always washed ashore in modest quantities in the spring and summer, providing habitat for marine life and helping build beaches as it decays.
But 2011 brought too much of a good thing. Way too much.
Without warning that year, sargassum suddenly swamped shorelines. It piled several feet high on some beaches. It stank like rotten eggs as it decomposed. It shut down resorts, dealing a major blow to a tourism sector in some areas of the Caribbean still struggling to recover from the 2008-2009 global recession. It gave coastal residents headaches, nausea and respiratory problems. It disrupted turtle nesting sites and threatened reefs and mangroves.
Sargassum has caused problems for boats operating at the ferry terminal in Road Town, Tortola in the British Virgin Islands (shown above on May 20, 2023.)
Credit: Freeman Rogers/The BVI Beacon
As sargassum continued to flood the Caribbean and the western coast of Africa 8,000 miles away, scientists made a surprising discovery. Historically, most of the seasonal influx in the Caribbean had come from a two-million-square-mile gyre in the northern Atlantic Ocean: the Sargasso Sea.
“The Sargasso [Sea] has been around for hundreds of thousands of years, and it’s an ecosystem that was perfect, so to speak,” said Dominican Republic oceanographer Elena Martinez. “It was there surrounded by four oceans gyres, or currents, that kept it perfect.”
But scientists soon learned that most of the new Caribbean influx wasn’t coming from the Sargasso Sea anymore: It was coming from a new sargassum ecosystem that had formed in the southern Atlantic Ocean.
The area dubbed the Great Atlantic Sargassum Belt ina 2019 article in Science is now visible from space, and its length often exceeds 5,000 miles, according to scientists who use satellites to track it.
Its cause is still debated. Sargassum researcher Dr. Brian Lapointe sees the Atlantic belt as a global version of a smaller bloom he witnessed in 1991 that shut down a nuclear power plant and other electricity facilities along the Florida coast.
Since the 1980s, the world population has nearly doubled, explained Lapointe, a professor at Florida Atlantic University. This, in turn, has led to a massive increase in the sargassum-boosting nutrients washing out of major rivers like the Mississippi in the US, the Amazon and Orinoco in South America, and the Congo in Africa.
“To grow that world population, we’ve used these fertilizers; we’ve deforested along all the major rivers in the world,” he said. “The nitrogen has gone up faster than the phosphorus from all these human activities, including wastewater, sewage, from the increasing human population.”
Another likely culprit is climate change. Martinez said warming waters may have disrupted the giant gyre that held the Sargasso Sea in place for thousands of years, releasing sargassum to float south and form the new belt.
Great Atlantic Sargassum Belt diagram. | REVIEW article Commercial Potential of Pelagic Sargassum spp. in Mexico, Frontiers
The new belt also receives additional nutrients from the Sahara dust that frequently blows across the Atlantic — which itself could be exacerbated by climate impacts such as the expansion of deserts as temperatures rise. Some scientists also argue that warming oceans provide a more sargassum-friendly growing environment.
Experts tend to agree that the Great Atlantic Sargassum Belt is here to stay — and that it is a global problem that needs a global response.
‘A terrible scene for the people’
That much was clear by 2018, when the belt grew to a record size that was estimated at 22 million tons and much of the Caribbean saw its worst-ever inundation. The season spurred increasing calls for a collaborative international response.
The following year, United Nations Secretary General Antonio Guterres visited St. Lucia for a July meeting of the Caribbean Community, and he took a side trip to the small fishing village of Praslin Bay.
Surrounded by dignitaries, Guterres walked down a dock lined with small boats bobbing atop thick mats of sargassum, which for years had plagued fishers, sea moss farmers and other residents in the area.
“So it’s a terrible scene for the people?” he asked a resident in a video posted on the United Nations website.
“Yes,” the man responded. “It’s killing the fishes in the bay. The stench. It’s destroying our electronics because of the fumes.”
After his visit, Guterres described his sadness on seeing a “landscape that resembled an algae desert for hundreds of meters.”
Then he called for international action.
United Nations Secretary General António Guterres visits Praslin Bay, St. Lucia in July 2019 on the sidelines of his attendance at the Caribbean Community Heads of Government Summit that year.
Credit: United Nations
“Oceans don’t know borders, nor does climate,” he said. “It is a global collective responsibility to take action now.”
But that broad international action has not materialized as planned. Despite a growing patchwork of studies and projects across the region, various attempts by the UN and others to coordinate a Caribbean-wide response have been largely stalled by funding shortages, geopolitical issues, the Covid-19 pandemic and other factors.
One of the most extensive efforts came about three months after Guterres’ visit to St. Lucia, when Guadeloupe hosted the First International Conference on Sargassum in October 2019. Partners at the event — where the three-year Sarg’Coop program financed by about $3.2 million in European Union funds was officially launched — included the French government, the Guadeloupe Region, UNESCO and other entities. In attendance were representatives from more than a dozen Caribbean countries and territories, as well as the US, Mexico, Brazil and France.
Some progress followed. For instance, the Guadeloupe Region — in partnership with the French government, the French National Research Agency and two Brazilian agencies — launched a call for projects that enabled a dozen international studies to be carried out on the health, environmental and economic impact of the seaweed, as well as possible uses for it.
Other regional meetings have been held since then as well. Last June, for instance, an European Union-Caribbean conference on “Turning Sargassum into Opportunity” was held in the Dominican Republic, and the topic was discussed the following month at a summit of the EU and the Community of Latin American and Caribbean States (EU-CELAC) in Brussels, Belgium.
But almost five years after the 2019 Guadeloupe conference, the broader goals have not come to fruition on a regional level as envisioned, experts acknowledge. No Caribbean strategy is in place, and the region-wide warning and monitoring center envisioned at the conference has not been established.
Large sargassum mats sweeping into the shoreline in Manchioneal, Portland, Jamaica – one of the top three worst affected areas in the island.
Credit: Mona GeoInformatics Institute
Instead, many of the actions that grew out of the Guadeloupe conference have centered mainly on the French Caribbean. Funded in part by about $66 million allocated for 2018 to 2026 by the government of France — which for decades has struggled with algae washing ashore on its European coasts — the French islands have launched some of the most extensive response efforts in the Caribbean in recent years.
But even this has not been enough to protect residents.
Describing Guterres’ visit to Praslin Bay as “nothing more than a photo op,” Martinique-based professor Dr. Dabor Resiere and seven otherresearchers claimed in a March 2023 article that the “local authorities failed to take advantage of such an important visitor to give international recognition to the sargassum phenomenon in the Caribbean.”
Four years later, they added, the situation remained “unchanged.”
“Despite the French government’s plans to tackle the sargassum problem, these toxic algae are continuing to inundate the coasts of Martinique, Guadeloupe, and French Guiana in ever-greater volumes,” the researchers wrote in the Journal of Global Health, adding, “Today, there is no national and international consensus on facing this public health problem. There is no Caribbean network or a broad consensus to advance research at this level.”
Even Praslin Bay saw scant relief in the years after it welcomed the UN secretary general.
In 2022, St. Lucian sargassum researcher Dr. Bethia Thomas produced videos aboutthe village andtwo other nearbycommunities as part of her doctoral thesis. In each video, several residents listed complaints ranging from breathing problems to fisheries destruction to corroding jewelry.
“It affects how I breathe, and I also think it affects the children and the way that they function, because sometimes they’re so moody and they cannot sit and do the activities because it’s so awful,” a teacher says in the video of Praslin Bay. “And I think it’s affecting us mentally.”
Concerns about sargassum’s effects on the mental health of coastal residents and workers were noted in a September 2023 report by the 34-member Western Central Atlantic Fishery Commission. “The unpleasant odor, the deterioration of their environment, lack of access to the beaches for relaxation, uncertainty about the future, increase in physical ailments such as respiratory illness and skin rashes, and concerns about other potential health risks, among other things, will naturally affect mental health,” stated the commission, a regional fisheries body established under the United Nations’ Food and Agriculture Organization.
However, the report added that such mental health impacts are not currently being studied.
In the absence of a regional strategy, national sargassum management plans have been developed in most countries and territories in the Caribbean, including eight through grant-funded projects affiliated with the University of the West Indies in St. Lucia, Barbados, Dominica, Grenada, St. Vincent and the Grenadines, BVI, Anguilla and Montserrat.
But few have been officially adopted at the government level, and even fewer are adequately funded or closely followed.
Sargassum lines the shore in July 2023 in Anegada in the British Virgin Islands.
Credit: Freeman Rogers/The BVI Beacon
“Sometimes the small communities get left behind,” Thomas said. “Maybe not intentionally, but in small island developing states with limited resources, you have to prioritize. And perhaps other things — like building a new hospital and constructing new roads, new schools — might take precedence over developing a sargassum management plan.”
Partly as a result, sargassum responses can vary dramatically from island to island.
But in probing major influxes in six Caribbean countries and territories last year, CPI found one constant: people are suffering.
Negligible investment from polluting countries
As residents experience health and economic consequences, Caribbean leaders often complain about a shortage of money to deal with the crisis. Local funds, they note, are tied up with many competing priorities, including handling climate-related impacts like hurricanes, droughts and flooding.
They also say that the cost of the sargassum crisis should be shouldered in part by the larger countries mostly responsible for it, but that accessing international climate financing for the purpose is not easy.
A CPI review of projects funded by the Global Environment Facility and by members of the Organisation for Economic Cooperation and Development between 2000 and 2021 found out that of the hundreds of billions of dollars spent on climate change projects in the world, less than $7 million went to address sargassum-related issues. About 89% of those funds, or $6 million, were spent in the Caribbean.
But for many non-independent islands, the problem is compounded by a political status that renders them ineligible for most climate financing.
“We have no access to global funds: Resilience fund, the loss-and-damage fund,” said BVI Health and Social Development Minister Vincent Wheatley, whose home overlooks the Virgin Gorda desalination plant that was recently damaged by sargassum.The sargassum that filled Handsome Bay, Virgin Gorda (shown above on Sept. 1, 2023) was sucked into the intake pipe of the island’s main desalination plant and caused damage that led to water shortages and cut-offs.
Credit: Anika Christopher/The BVI Beacon
At the annual UN Climate Change Conferences, he explained, overseas territories are not parties and don’t have their own seat at the negotiating table.
“We fall under the [United Kingdom],” he said. “So whatever the UK negotiates, it will pass on to us.”
Therefore, he said, the BVI and other overseas territories have been in separate negotiations with the UK.
“We banded together to petition the UK to carve out a specific fund for [its] overseas territories,” he said, adding that these discussions are ongoing and include sargassum.
A lack of funding and regional coordination has also stymied efforts to monetise the seaweed by finding a large-scale sustainable use for it.
“Even though there are so many things you can make with sargassum, the actual amount of sargassum that is used for products is still very low,” said Dr. Franziska Elmer, a sargassum researcher based in Mexico.
Sargassum plan proposed at COP28 in Dubai
The 2023 sargassum bloom in the Caribbean had mostly abated by Dec. 2, when Gustave dit Duflo, the French Biodiversity Office president, stood at a podium 8,000 miles away during a side event at the COP28 meeting in Dubai.
As dignitaries looked on, she issued a stark warning about sargassum.
“It is a very invasive and aggressive phenomenon, and through all the Caribbean it affects tourism, and all the economies of the region are based on biodiversity and tourism,” she told those gathered at the French pavilion on the sidelines of the conference. “The Caribbean has a lot of hot-spots of biodiversity. So if we don’t act, in 20 years this marine biology, including the reef, will disappear from our coast.”
She then explained the French government’s proposal to address the issue. The program, she said, has four prongs: forming an international coalition to better understand the problem and its causes; addressing sargassum in international forums like the COP of Biodiversity; acting in the framework of the Cartagena Convention; and working with the EU to support the continuation of the regional Sarg’Coop project launched during the 2019 conference in Guadeloupe.
The French government has presented the proposal as an unprecedented move at COP 28, with the aim of placing the sargassum issue on one of the high-level panels of the United Nations Conference on the Oceans to be held in Nice, France, in June 2025.
Such collaboration is essential, according to Gustave dit Duflo.
“We manage sargassum at a local level, but this is not a phenomenon of an island. It is the whole basin of the Caribbean and a part of the Atlantic,” she said. “This is why all the countries that are impacted, we need to create an international coalition to be able to find means and ways to act.”
Since COP28, the Netherlands and its overseas countries and territories decided to join the international program proposed by France alongside Costa Rica, Mexico, Dominican Republic and the Organisation of Eastern Caribbean States, Gustave dit Duflo told CPI.
A meeting will be held soon with the European Commission to define the project’s legal guidelines and financing, she said.
Also at COP 28, the EU and the government of the Dominican Republic co-organised a related panel at the Dominican Republic pavilion, where they launched an initiative to “turn sargassum into an economic opportunity” by tapping the EU-Latin America and the Caribbean Global Gateway Investment Agenda.
To succeed, such projects will need to build on work that came out of efforts like the 2019 conference in Guadeloupe — and overcome the challenges that delayed them.
Since early 2019, for instance, Météo France, the French weather service, has been operating a sargassum monitoring and detection service in the French West Indies and French Guiana. But so far, these efforts have not expanded into the regional center envisioned at the 2019 conference despite various monitoring systems launched in recent years, such as the Jamaica Early Advisory System, the regionalCARICOOS tracker in Puerto Rico, and theSatellite-based Sargassum Watch System at the University of South Florida.
The Sarg’Coop program launched at the 2019 conference also planned to replicate work done in Martinique, which in 2015 had set up a hydrogen sulfide and ammonia monitoring system that was later developed into a large-scale measurement network and extended into Guadeloupe in 2018.
Under Sarg’Coop, the Martinique-based research institute Madininair was given responsibility for supporting St. Lucia, Dominica, Tobago, Cuba and Mexico in preparing similar networks. But the Covid-19 pandemic delayed progress, and only recently did the effort get back on track with work carried out in each of those countries.
Asked about the past obstacles to implementing a common international strategy, Gustave dit Duflo, also a lecturer in neuroscience at the University of the West Indies, pointed to geopolitics. As one example, she cited the May 2023 summit of the Association of Caribbean States in Guatemala. The summit discussions, she said, were largely dominated by the conflict in Ukraine as countries in the region debated the issue of supporting Russia or the United States.
Regional collaboration has also been hindered by legislative differences across borders, according to the scientist.
Guadeloupe senator Dominique Théophile made a similar observation when he was commissioned to conduct a study on sargassum management strategies in the Caribbean ahead of the 2019 conference. After several trips to St. Lucia, the Dominican Republic and Mexico, he found that the most successful area management plans were carried out by major hotel groups on a local scale.
But such strategies often could not be deployed throughout the entire Caribbean.
For instance, health and environmental laws in French and other European territories precluded a practice that is common elsewhere in the region — spreading sargassum behind beaches — because of the possibility that the seaweed could contain arsenic and other heavy metals that could affect the ocean or groundwater.
Because of such laws, Théophile explained, the French sargassum management strategy attaches heightened importance to health and environmental impacts. Often for financial reasons, other countries’ initiatives don’t address such environmental and health considerations in corresponding detail, he said.
As countries work to rectify such issues and establish an international response, time is of the essence for residents of the coastal Caribbean.
Shortly after the COP28 drew to a close, scientists at the University of South Florida estimated the sargassum floating in the tropical Atlantic Ocean at about five million metric tons, compared to a December average of about two million. By February, the mass had increased to some nine million tons — the second highest quantity ever recorded for the month.
In other words, another record-setting sargassum season could have just started.
Reporters Rafael René Díaz Torres (Centro de Periodismo Investigativo), Mariela Mejía (Diario Libre), and Hassel Fallas (La Data Cuenta) collaborated in this investigation.
This investigation is the result of a fellowship awarded by the Center for Investigative Journalism’s Training Institute and was made possible in part with the support of Open Society Foundations.