Five grab lorries were needed to remove a "carpet" of 80 tonnes of duckweed from a canal.

Stourport Basin in Worcestershire, was turned fluorescent green by the tiny, free-floating aquatic plant, and earlier in July it was reported a dog had drowned in the canal after it went into the water.

Charles Hughes from the Canal and Rivers Trust said Stourport Basin had one of the worst incidents of duckweed growth ever seen in the West Midlands, with the entire canal and nearby locations experiencing rapid widespread growth.  "We've been spending a lot of money and time trying to deal with this - it was a five day job which cost us £12,500," he said.

"Duckweed is very difficult to manually remove, because it's very small plants, but it can get quite heavy as well. Because they multiply and grow so quickly, they almost form these mats over the surface and often it can be quite deceptive, especially for people who come into an area they are not familiar with. You won't see any open water so it presents a health and safety risk," he added.



The task to remove the plant involved using a weed harvester boat, developed to specifically remove water plants. "We then remove it into a storage called a hopper before we take it away to be disposed of. We had five grab lorries worth which amounted to 80 tonnes of duckweed."

Mr Hughes said as the region experiences hotter and drier weather, it creates the perfect environment for the aquatic plant to grow quickly and invasively. "Over the last five years, we've been having to spend tens of thousands of pounds just in the West Midlands region alone. The annual costs of just managing aquatic weed can come close to the million pound mark," he said.