Celia Wigg Toxic levels of blue green algae have been found at Diss. The Environment Agency confirmed that it was first noticed on Friday at the mere, when a large amount of bright turquoise blue deposits were seen floating around the edges.

Celia Wigg

Toxic levels of blue green algae have been found at Diss.

The Environment Agency yesterday confirmed that it was first noticed on Friday at the mere, when a large amount of bright turquoise blue deposits were seen floating around the edges. Analysis of samples confirmed that it was blue green algae in its toxic state.

The town council has put up notices around the mere warning people to avoid contact with the water and to stop pets swimming in it. And families have been asked not to feed bread to the mere's ducks in case they make matters worse.

Contact with the algae can cause skin irritation and stomach upsets

in humans.Pets risk similar effects.

Although the algae bloom has dispersed, the Environment Agency says it will monitor the situation since further outbreaks are likely. As a precaution the town council has switched off the mere's fountain, which helps to aerate the water, to reduce the risk of spreading spores through the air.

The algae occurs naturally in warm and calm water where nutrient levels are high, and the agency has said there is a danger that the oxygen may become depleted in the mere - characterised by an apparent clarity in the water as the algae dies off and falls to the bottom.

This could mean that fish will die.

People are being asked to stop feeding the ducks as the potential for further, more intensive algal blooms exists unless the amount of nutrients in the water does not fall.

Town clerk Deborah Sarson said: "The environment office for South Norfolk Council has advised that this problem has probably been exacer-bated by over-feeding the ducks with bread." But she added that the council was looking at whether to install feed dispensers.

A spokesman for Anglian Water said: "We occasionally get outbreaks in reservoirs, and it's a case of doing exactly what they doing here - putting up warning signs and limiting contact for the public and dogs."