MURKY clouds of mud have been spotted flowing through the river north of Haverfordwest, with local anglers concerned about the effect it will have on the environment.

Facebook group Sea Trout Wales shared a video of the clouds of sediment spreading through the Western Cleddau at St Catherine’s Bridge, four miles north of Haverfordwest on Thursday, June 7.

A video of the sediment flowing down the river. VIDEO: Sea Trout Wales.

Members of the group reported the find to Natural Resources Wales after spotting it on Wednesday, June 6.

They later shared their disappointment in the condition of the river, and decried using waterways as a place to dump soil.

Tim Coupland described the pollution as an absolute disgrace.

He added: “I know how hard the club have worked to keep this stretch of the river as untouched and natural as possible with its lovely weedy runs and variety of plant life and trees.

“Then this happens and it's all wiped out...”

Michael Osbourne said: “The only way to beat it is keep reporting it hopefully get it sorted but watching that entering the water tonight no wonder the fish aren’t coming back into these rivers.”

The incident was reported to Natural Resources Wales, who were unable to attend immediately.

On June 7, a spokesperson for NRW said: “We are today continuing the source of pollution which affected the Western Cleddau near St Catherine’s Bridge, north of Haverfordwest, Tuesday evening.

“After receiving the initial reporter our out-of-hours duty officer immediately instigated our response procedures in line with our 24 hour guidance.”

NRW spent a full day at the river on June 6 trying to track the source of the pollution and was investigating nearby premises, but said it was too early to confirm what the exact course was.

The spokesperson added: "We’re working with key land managers in the area to prevent further incidents of this nature, and would advise landowners to take precautions during excavation works near rivers, especially when rain follows periods of dry weather can wash large amounts of soil into rivers.

"The soil will cover river beds and invertebrate habitat causing a direct impact on fish as they rely on this source of food."

The agency added that any further signs of pollution on the river can be reported via its incident hotline: 0300 65 3000.