The Canal de la Somme has beautifully clear water and lots of wildlife – birds, insects, dragon flies, damsel flies and frogs! All signs of a heathy waterway.
However, it is extremely weedy. Very thick weed causing a dense carpet on the surface in places.
It is much worse this year than when we were here 3 years ago. We are having to take great care to follow the channel, cut by previous boats, through the weed & not to use our bow thruster. At some mooring places it is impossible to moor because the weed is so thick you cannot get through. Boats are advised to use reverse to clear propellers & boats with water cooling engines have to take extra care to clear filters.
Apparently throughout April they were cutting the weed and plan to do so again from July 11th. It grows that fast.
The Somme leaflet describes it being impacted by ‘D’espèces Exotiques Envahissanes – Myriophylle Hétérophylle’. It is so dense that it could adversely impact fishing, water sports, navigation and the biodiversity of the waterway. Every year a scheme of cutting and removal is undertaken. 2019 = 360,000 eus.
One of the eclusiers told me that they didn’t really know where it had come from but that it is thought to be an aquarium plant. People emptying aquaria into the water system may have inadvertently caused the problem. And it really is a problem.