Mark Tamburrano, who skippered the Beta barge, was seen throwing rubbish into the sea close to shellfish beds in Torquay Bay.
The skipper of a barge has been fined £500 and more than £2,000 in costs, after pleading guilty to dumping rubbish at sea.
The court heard that on the morning of 26 May, 2016, the barge, Beta, was sailing from Exmouth to Plymouth.
In charge of the vessel was Mark Tamburrano, a 33-year-old restaurateur from Plymouth.
He was moving the barge to Plymouth for conversion into a floating fish restaurant.
As the vessel passed close to Torquay Bay, witnesses from the Food Standards Agency and local Environment Health department, who were visiting shell beds nearby, saw rubbish being thrown from the barge.
This included a number of bin bags with plastic in them, along with gas canisters and a chemical toilet.
The witnesses approached the barge and the dumping stopped.
Tamburrano appeared before Torquay magistrates court on 10 October, where he pleaded guilty to charges brought by the Maritime and Coastguard Agency (MCA).
He was fined £500, plus £50 surcharge and full costs of £2,291.31.
In summing up, the magistrate said there had been no obvious intent to dump rubbish at sea but it is obvious an offence has been committed.
A fine would be imposed because of the material thrown overboard and its environmental impact on local fishing, as well as its proximity to the coast.
Commenting on the case, MCA surveyor operations manager, Tony Heslop, said: “The law is very clear and there for a purpose – the protection of the marine environment.”
“What makes this case worse is that this was a seafish restaurant owner throwing rubbish overboard so close to the shellfish beds and beaches of Torquay. Such behaviour is always unacceptable and it is the duty for those who make their living from the sea to protect it,” he stressed.