Distribution, abundance and pollution tolerance of the marine invasive sponge Celtodoryx ciocalyptoides (Burton, 1935) in the Etel River.

The distribution and abundance of the marine invasive sponge Celtodoryx ciocalyptoides is described for the first time along the Etel River, a Natura 2000 site of the French Atlantic coast. This invasive species is now well established along both sides of the Etel River and has colonized about 29.3% of the surface of the rocky reef at a depth of 10-18 m. In the Etel marina, C. ciocalyptoides covers all the pilings with a covering rate estimated to 17.4% between 5 and 9 m deep. The bioaccumulation capacities of this species exposed to metallic and organic pollutants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organotin derivatives) was also measured during a three-year study in the Etel marina. Preliminary results suggest this marine invasive species has the capacities to adapt in few months to its changing environment by sequestering and/or metabolizing those pollutants.