From the Norfolk Broads Authority
The Environment Agency have confirmed that toxicity levels from Blue-Green algae have been sampled at the following locations: Neatishead Staithe, Irstead Staithe, Gaye's Staithe and South Walsham Staithe.

Please take particular care and ensure dogs and humans do not enter the water. Please exercise caution in other locations and report any further sightings to the Environment Agency's hotline on 0800 807060.
BBC News: East of England BBC Radio Norfolk

In case anyone is on holiday in the Broads area..........

Thanks for this as we sometimes venture into Norfolk. Think we will stay put by the coast and immerse the dog in the north sea at regular intervals

Thought it was worth copying as I knew there were some folk who stayed/visited the area and maybe wouldn't have seen the warning :-)
Agree sea is probably a lot safer.

This was mentioned for nationwide contamination  on another part of the forum a week or so ago.

Apart from the fact that, if a dog ingests spores from blue green algea it  will start to work within only a few moments, as example, if you have half hours walk left to get back to a car its unlikely that a dog will still be able to stand by itself & less likely still that you will get to a vet in time, even then I am not sure a vet can do anything at all at that stage.

One of the most misleading aspects of 'blue green algea' is the name, i does not neccesarily 'look' blue as we see things, it more often than not simply looks like the green algea we are more familiar with, see link to photos of 'Blue' green algea.
Photo's
https://www.google.co.uk/search?client=opera&q=photos+of+blue+green+algae&sourceid=opera&ie=UTF-8&oe=UTF-8
.