“Let nature take its course” is the advice of the Brayford Trust as green sludge known as duckweed continues to cover Lincoln’s Brayford Pool.
David Rossington, of the Brayford Trust, explained to The Lincolnite that the issue with duckweed in Lincoln normally happens annually around this time of year.
It is also present in the Witham and Fossdyke, although the extent of the problem can vary.
David told The Lincolnite: “I don’t think a lot can be done about it. We have to put up with it and it will disperse over the next few weeks.
“So far as possible we need to let nature take its course. It’s not algae or anything concerning like that.”
The Brayford Pool is operated by the Brayford Trust, while The Canal & River Trust is responsible for a two metre channel down the middle of Brayford Pool.
Meanwhile, a mix of duckweed and an invasive species called azolla is causing a problem in the River Witham in Boston. However, the majority of the weed is duckweed.
The Canal & River Trust released small bugs called weevils that eat the azolla in order to try and break the weed. Unfortunately, weevils do not eat duckweed.
The weevils were not put into Lincoln’s Brayford Pool, and only in at Boston as the azolla, along with the duckweed, is restricting use of the rivers by boats.
An additional weed boat was put on the river and the trust is removing between 300 and 500 loads of weed from the navigation each week. The trust also continues to flush weed through its own lock at every opportunity.
The Environment Agency has been operating the sluices weekly to try to flush the weed.
The Canal & River Trust said last month that it was aware of concerns from anglers regarding conditions for fish in the river and oxygen levels.
It said: “The oxygen levels are a concern, though regular flushing at the lock does mean they recover quickly.”