In the same way that the proliferation of jellyfish has become a global problem, many countries are now affected and impacted by a new phenomenon of large scale, linked to massive stranding of different varieties of invasive algae. The problem that is now present in China (Qingdao and Shandong region), France (Brittany), the United Arab Emirates (Dubai), and North America (Florida) seems to be intensifying in a worrying way and regularly leads in the name of the precautionary principle to bathing bans.
Since 2011, the proliferation of algae called Sargassum (Sargassum Natans and Sargassum Fluitans) has attracted all observers' attention and concern.
The coasts of Martinique, Guadeloupe, Mexico, the French West Indies, the Caribbean, Guyana and Barbados are directly concerned by this phenomenon which represents a visual disorder, a major economic, ecological and health threat; unprecedented for all the countries concerned.
– Economic Consequences
Every year, just a few months before the peak tourist season, many municipalities are forced to release emergency funds to finance costly and exhausting cleaning operations that have now become daily exercises. On the island of Tobago (Caribbean Sea) faced with the enormity of the problem, local authorities have been forced to declare to be in a state of "natural disaster".
"This year was the worst we had. We need regional action to solve this problem because this unsightly seaweed could end up affecting the Caribbean's image. »
Christopher James, President of the Tobago Hotel and Tourism Association.
The sublime postcards of white sand and turquoise water have given way to kilometers of shores and beaches, to huge carpets of decomposing seaweed that is several tens of centimeters (more than two meters in certain geographical areas) in thickness.
Apart from their denaturing visual appearance for sites where they come to run aground, Sargasso algae when they decompose release various gases including H2S (hydrogen sulphide) which can create worrying public health problems during prolonged exposures. Irritation of the eyes, throat, ears and nausea. The impact of this phenomenon on the tourist economy of the affected regions therefore comes with severe consequences. Moreover, it has recently been discovered that these stranded algae swarm with annoying parasites such as sand fleas, causing allergic reactions and skin irritations.
In 2015, the number of shorelines disfigured by the invasion of these algae is so high that more and more tourists are making the decision to cancel their summer holidays rather than having to discover affected and nauseating sites.
In Martinique, the environment, planning and housing department evaluated in September 2014, the surface of Sargasso seaweed present along its coast to more than 177 hectares and the Guadeloupean authorities evaluated in June 2015 the mass of algae to be treated at more than 60,000 tons.
At an international summit held in Barbados on August 18, 2015, experts estimated that Sargasso seaweed's economic impact on the concerned geographic areas to be more than 120 million US dollars.
– Ecological and Environmental Consequences
Sargasso algae pose a set of interdependent issues that are detrimental to fragile balances of endemic biotopes and eco-systems.
Sargasso algae directly threaten marine turtles that come to lay on the beaches. The thick cover of tons of seaweed agglomerated daily, constitutes a double danger for this protected species. Either algae prevent turtles from accessing their traditional spawning grounds, causing a state of stress and dangerous disorientation directly threatening species' reproduction. In some extreme cases, strands of algae trap the turtles after they have laid their eggs. Exhausted and asphyxiated by hydrogen sulphide (H2S), the toxic gas released by decomposing algae, the latter eventually die on the spot.
If the different observers thought so far that Sargasso seaweeds at sea represented no danger, it turns out that their presence in the form of thick sheets covering large areas sometimes greater than several hectares, generates what we consider today to be many undesirable effects.
- They would have the effect during their migratory journey of disseminating non-endemic species of large invasive fish such as the lion-fish. A fish classified as among the most dangerous of the marine world.
- The large "rafts" formed by these algae could eventually stop photosynthesis thereby threatening corals and sea-grass beds.
- Many dead fish have been discovered by Park agents in Guadeloupe at the Saline River, which suggests a direct link with the algae and their ability to alter the water, in a phase of decomposition.
Thus, all local ecosystems are potentially threatened by the phenomenon.
Finally, the mechanical collection solutions implemented urgently, by the local authorities of the different areas concerned, if they are visually effective, do not solve the problem and moreover generate collateral damage. In addition to the fact that the storage of algae has the effect of moving their nuisance to other places, their collection directly on the beaches with a periodicity of two to three days, ultimately involves an inevitable collection of large quantities of sand and accelerates an already ominous erosion process.
Pollution which is gradually contaminating the oceans and climate change, directly impacting certain marine currents are among other phenomena causing the exponential propagation and massive stranding of algae, including red algae (United Arab Emirates), green algae (Brittany, China) and Sargasso algae.
According to experts, more than 75% of marine pollution in the world is from land-based sources and therefore from land-based sources, either directly or indirectly related to human activities. These chronic pollutants affect all the world's seas and it is now recognized that nearly 70% of chemicals dumped in the Pacific do not receive any form of prior treatment. This alarming observation suggests a concentration of phosphates, nitrates and pesticides that is totally abnormal and cannot be assimilated by the concerned oceans and the eco-systems.
"There are an estimated 100,000 human-made chemicals introduced into our daily lives. But most of them end up in oceans, unable to assimilate them. »
Magnus Jóhannesso, Secretary at the Icelandic Ministry of the Environment.
All river systems bring huge quantities of chemicals every day to the sea in the form of pharmaceutical residues, pesticides, fertilizers and other additives. The discharge of wastewater from river or coastal emissaries leads to the presence of an excessive amount of nutrients that promote not only the rapid proliferation of algae but also jellyfish.
For a long time, scientists believed that Sargassum seaweed came only from the sea bearing same name. For some specialists and observers, it seems that in reality this sea is no longer their only place of birth. Sargasso algae also come from northern Brazil and French Guiana. Carried by the Caribbean current, the algae would find a quantity of nutrients sufficient to develop very quickly in the zone of the Amazon river. From this point of multiplication, they would take advantage of large intercontinental currents (such as that of the West Indies) to colonize the world.
Pascal Saffache, professor of Universities in geography in Martinique, indicates that "these algae seem to arrive rather from the south of the Caribbean archipelago" and "that it was observed in the North of Brazil an important bed of Sargasses, 8000 km long and 120 km wide. This proliferation can be explained by a significant presence of nutrients in the water, partly linked to the presence of humans, which contribute to the proliferation of algae".
With our long experience in the management of local communities, the problem of jellyfish at their invasive stage and their consequences on health and the economy, we provide you with a set of exclusive services and skills, which no other company is now able to bring together within one and the same entity.
- Scientific and Biological Skills.
From current simulation to physical pre-location, from global containment to the protection of targeted geographical areas, from collection to storage and recovery, the Marine Pollution Response Group (GIPM) and Pollustock are able to bring you a reference expertise in Sargasso seaweed management all over the world.
Our operational teams consist of specialized and experienced divers, can be detached on different sites and in different frameworks of missions and this over periods ranging from a few days to several months.
From the implementation of floating barriers against Sargasso algae and similar equipment, to the supervision and training of local teams, our missions are part of an international cooperation scheme.
Since 2009, starting from the principle that any problems impeding its solution, our ambition is to bring adapted and perfectly rational answers to all the invasive situations disturbing the balance of the aquatic environments.
For us, the management of Sargasso seaweed must be part of a vast program for the protection of the coastal zones, whose objective is to permanently stop the grounding.