Photographs show how Birmingham's famous canal network has turned GREEN after being taken over by a carpet of thick duckweed.
The usually clear waters have been transformed into "a swamp" around Gas Street Basin - the heart of the city's canal network.
The murky weeds have exploded after recent high temperatures as well as rainfall which has caused them to rapidly bloom.
Photos show kayakers paddling through pea soup-like waters while other parts of the canal are completely covered by a blanket of green.
The aquatic plants are harmless in small amounts, but can prevent oxygen getting into the water when there are high volumes causing a blanket across the surface.
It can also cause issues for narrowboats on the canal, has an unpleasant smell and be mistaken for grass by unsuspecting dogs.
A Canal and River Trust spokesperson said: "Duckweed highlights a real challenge that the Trust faces going forward.
"Due to climate change we are seeing a real growth in its presence and growth.
"The main cause is down to an increase of nutrients being washed into the canals through intense rainfall.
"Unfortunately, it multiples in the summer at a phenomenal growth rate and is incredibly difficult to manage and impossible to remove from the waterways.
"The Trust spend thousands every year trying remove it and mange it, but the growth rate is far beyond what we as a charity can deliver and afford, and this will only get worse.
"This isn’t just a problem for the local canals, this is a challenge across the country.
"We will continue to do what we can with our limited budget and resources but we are always looking for people to help us manage this and anyone wishing to support can visit our webpages to see how they can help."
Jack Vurlan, 39, a commuter who regularly walks into Birmingham city centre via the canal towpaths said: "It just seems to be getting worse and nothing is done.
"It looks like green sludge. This part of the city is usually lovely to walk along but now it's been turned into a swamp."
