A river plant has engulfed a canal, trapping rubbish and turning it into a sea of green.

Duckweed has grown with the warmer weather and has been covering a large part of Regent’s Canal which runs across the length of Islington.

Residents have raised concerns about an increase in litter now resting on surface.

Mike Sweeney, 50, of York Way, Islington, who regularly jogs along the canal, said: “I have lived here for 10 years and never seen anything like this before. It covered the length of the canal from Caledonian Road to Camden. Quite a lot of rubbish has been trapped on top. This has become a bit of an eyesore and you wonder how swans and natural wildlife will cope.”

Resident Alan Stafford said: “In some places the whole canal has turned green. The weed’s so thick it looked like you could walk right across. You can see bottles stuck fast in it.

“It is like a river of pea soup. I guess it is the crazy summer weather. It makes you wonder if it sucks oxygen out of the water for other plants and creatures.”

Nayna Wood, a spokeswoman for British Waterways which manages the canal, said: “At this time of year a combination of the hot and humid weather with a slow-flowing waterway means duckweed grows incredibly vigorously, often, as your reader says, covering the whole navigation. It is a native plant and incredibly common across all canals in the UK. It doesn’t pose any risk but unfortunately it does tend to trap rubbish.

“We have doubled our resources in the area to minimise the growth and this tends to keep it at a steady state as the growth is so vigorous. It will subside when the weather cools again.”