Water pennywort, an exotic invasive plant that colonizes the Sambre

For several years, the Sambre has been covered by water pennywort. Behind this barbaric name, a very invasive exotic plant that threatens the ecosystem and navigation on the river.

It is an invader that continues to expand on the banks of the Sambre. Water pennywortan invasive exotic plant, wins 10 centimeters per day. From Landrecies to Berlaimont (59), it literally covered the river. Problem, there is not really room left for fishermen to put down their rods. “It was overnight, in a month it was everywhere. In terms of places, you can’t sit where you want. The fishing field is reduced compared to before”, regrets Patrick Jamotte, fisherman. There navigation is also impacted, as well as the hydrological management of water bodies.

A plant used in aquariums

To protect the ecosystem and stop the progression of the pennywort, Waterways of France and the Avesnois Regional Natural Park have joined forces. Because the plant is not easy to dislodge. Pulling it off can even trigger its gearing down. “A fragment can be the start of a new colony of several tens or hundreds of m²”, explains Guillaume Caffier, project manager at the Avesnois regional natural park. The origin of the pennywort remains uncertain. “The first point we discovered was in the commune of Ors and it all started from there. How did she get there, we don’t really know. It is assumed to be an aquarium release, as it is used as an oxygenating plant.” continues Guillaume Caffier. Only solution for now filter dams placed on the Sambre.