Killer algae set to hit Broads?

The fish stocks on the famous Norfolk Broads look set to be put under urther pressure after experts warned that a proposed dredging operation could release deadly toxins into the water.

Some of Norfolk's leading predator experts have raised concerns over Broads Authority plans to widen and deepen the boat channel at Heigham Sound on the River Thurne, warning that the work could disturb the algae Prymnesium parva and release floods of fish-killing poisons.

Local and national angling clubs fear a repeat of the deadly prymnesium blooms which devastated the Thurne system in 1969, killing countless bream, tench and pike, including a huge 42lb specimen.

Last February, the river produced a 45lb 8oz pike for John Goble ­ the largest pike ever taken from running water, and was also the scene of Neville Fickling's 41lb 6oz British record pike back in February 1985. It is irreplaceable specimens such as these which experts feel could perish if the fragile ecosystems are not managed sensitively by the Broads Authority.

"There is strong evidence that dredging and weed cutting can cause prymnesium outbreaks due to disturbed sediments. The 1969 outbreak which began on Horsey Mere was triggered by pumping and dredging," said Broadlands pike expert Stephen Harper.

"Anything which disturbs the bottom during warm water conditions can trigger an outbreak. We're not convinced there's any need in this case," he added.

His concerns were echoed by Stephen Roberts, chairman of the Norwich and District Pike Club, who said: "We want the Broads Authority to defer action until the science is done to prove fish stocks won't be harmed. We also want assurances that they're not seeking to stop anglers from fishing Duck Broad."

But those in charge of the dredging project are insisting that any work they do carry out will be closely monitored by their partners at Natural England and the Environment Agency.

"Boaters have raised concerns over groundings in the area, so we'll be conducting a small step-by-step trial dredge to start with, monitoring the water and algae to ensure there's no threat to local wildlife," said the Broads Authority's waterways conservation manager Dan Hoare.

"Removing nutrients in the sediments will improve general water quality for years to come, benefiting anglers and fish alike," he added.