The oyster dredging season in Cornwall has begun following concerns over E.coli earlier in the year.
There had been fears that the Truro and Fal river system fisheries could remain closed because of poor water quality.
Samples taken in in the Fal estuary in August included saw levels 400 times over the legal limit. It followed a ban imposed in April.
The Truro and Falmouth Port Health Authority said the water had been given a clean bill of health.
Earlier in the year, samples in the Fal fishery area revealed one reading, in Mylor Pool, that greatly exceeded what is permitted under Food Standards Agency (FSA) rules.
The FSA states the maximum level permitted for shellfish production is 4,600 parts E.coli per 100g of shellfish flesh. Fishermen said they were told it was well in excess of 1.8m parts.
Chris Ranger, from Cornish Native Oysters, said he was glad the "devastating" ban had been lifted.
He said: "I was shut down for 20 weeks. I still had to pay the rent, but I couldn't even turn the tap on."
The port authority confirmed it had declared the water safe.
The Environment Agency is looking into possible causes of pollution.