She has a barbaric name and scares everyone.
It was around an islet in the Port-Cros archipelago, off Lavandou (Var), that the algae was discovered by chance by divers.
While observing the populations of nacre, they came face to face with several red carpets of this filamentous algae.
“It is an invasive species, unknown until now, which risks disrupting the functioning of local ecosystems, indicates the natural park of Port-Cros, worried.
Its development in a carpet can become so dense that significant damage is to be feared, especially within Posidonia colonies.
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She scares the fish away
How could this exotic seaweed end up in the Mediterranean from the Indian Ocean and the Red Sea?
“I am thinking of a hypothesis: a leak of this Lophocladia Lallemandii after the enlargement of the Suez Canal, which would have allowed it to reach the Mediterranean, indicates Charles-François Boudouresque, professor emeritus at the Mediterranean Institute of Oceanology. .
The Mediterranean is the sea that hosts the largest number of introduced species.
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The problem is that red algae has the specificity of scaring fish away.
“It has toxic substances that cause herbivorous fish or sea urchins to turn away from it and not consume it.
As a result, the algae expands because the herbivores make room for it to proliferate.
Spotted in the south of Italy and Tunisia, it is now developing near the French coast.
A bad sign for marine balance.