The aircraft carrier Sao Paulo, ex-Foch, in June 2011. Reuters
FOCUS – Environmental defense associations evoke a “crime” and a “disaster” for marine biodiversity after the “planned sinking” of the renamed ship São Paulo after its sale in Brazil.
The long wandering of the former flagship of the French Navy ended this Friday, February 3. The Brazilian sailors sent the aircraft carrier Foch to the bottom, claiming that they no longer had a choice given the very degraded state of the old hull. Its wreck now lies 5000 meters deep, in the heart of the Atlantic.
The associations for the protection of the seabed and the defense of the environment had nevertheless warned. The scuttling of this “toxic package of 30,000 tons”, as the Robin des Bois association has described it, is a real “environmental crime».
The gigantic ship indeed contained a lot of toxic materials and in particular “9.6 tonnes of asbestos, a potentially toxic and carcinogenic substance, as well as 644 tonnes of paint and other hazardous materials,” had alerted the federal ministry of Brazil which multiplied the recourses to try to stop the operation, in vain.
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«There are 17km of piping insulated with asbestos and about ten kilometers of PCB sheaths“, details for Le Figaro the Robin des Bois association, which is based on the inventory carried out on the Clemenceau, the sistership of the Foch, during her dismantling in the United Kingdom. “We are also talking about hectares of coatings, varnishes, lead paint, etc.».
Organisms destroyed
To what extent do all these toxic substances represent a danger for the environment? The Robin des Bois association evaluates this “environmental disaster” in two times. “First there is the immediate time, this night, today and tomorrow when an entire abyssal community and a tremendous amount of organisms are destroyed“, we explain. “And it comes at the wrong time“. Because it is true that the international community is increasingly mobilizing for the protection of the seabed. Brazil in particular, with other Latin American countries, is pushing to establish a whaling sanctuary, precisely in the vicinity of the scuttling of the Foch.
But the consequences of the scuttling of the aircraft carrier will be assessed especially over the long term. “The more time passes, the more the wreck will decompose, with all its toxic products which will decompose“, indicates the association Robin des Bois. “The materials thus broken down into dust and scales will become available for fish and marine mammals, and many residues will also aggregate with plankton and contaminate countless marine resources.».
On large military buildings such as the Foch aircraft carrier, we must not forget the staggering quantities of hydrocarbons and other lubricants, which the dismantling sites pump out meticulously before starting their work. If Brazil has undoubtedly taken some precautions, “there are obviously residues», estimates the association.
Aging wrecks
And this problem has often resurfaced several decades later for ships dating from the Second World War or even the war of 14-18. The wreck of the British tanker SS El Grillo, among other examples, sunk in 1944, required several operations of pumping and extraction of hydrocarbons and ammunition. If 2000 tons have been extracted, tanks still remain and continue to leak intermittently as corrosion eats away at the hull.
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The older the wrecks, the more they become fragile and can be potentially polluting. “Decomposition is slower at greater depth because the water temperature is lower, there is less oxygen and less light“, also explains the diver and explorer Alexis Rosenfeld. For him, it would have been more virtuous and pragmatic to first decontaminate the structure in a construction site, then to create a “time capsulein shallow water that would have made divers happy. “There are exceptionally well-preserved shipwrecks in the Black Sea, like this Greek trading ship that sailed 400 years BC, the oldest known intact shipwreck “. But the decomposition of a wreck is in any case inevitable, and the scuttling of the Foch with all its toxic waste on board is helping to transform into “garbage canthe oceans, denounces the explorer.
Despite its impressive 264 meters, can the Foch still be compared to a drop of pollution in the immensity of the Atlantic Ocean? “It joins thousands of other wrecks“, we answer at Robin des Bois. Warships, freighters, oil tankers, chemical tankers…”Over time, and under the combined effect of corrosion and currents, these wrecks become fragile and can release their contents into the marine environment. Scientists are sounding the alarm and urging governments to act on ‘these ecological time bombs’“, raised the National Defense Review in an article published in 2020.
TO HAVE ALSO – Brazil sank the contaminated former aircraft carrier Foch in the Atlantic