Owners and the master of the Belgian beam trawler "Neptunus" were ordered to pay a total of £43,374 in fines and costs by Lowestoft Magistrates, UK, on Monday 8 September after pleading guilty to fishing with blinders in both trawl nets.

In the case brought by the Marine and Fisheries Agency, magistrates levied fines of £34,000 to the value of the catch, £1,700 for each of the four offences, and confiscated "Neptunus"s gear including both beams, shoes, nets and chains.

The bench heard it was the second time "Neptunus" skipper, Frank Vandewalle, 37, of Blankenberge, Belgium and owners Olympus NV of Zeebrugge had been caught using blinders – netting fitted inside the codend - in their trawl nets which prevents the release of immature fish.

In court lawyers for the master and owners said the blinders were being used to protect the net from chaffing on rocks during bad weather.

After the case an MFA spokesman said: "The Agency takes offences against the technical regulations very seriously and in particular when they are detrimental to the release of juvenile fish.

"The evidence in this case was overwhelming and in the Agency’s view this was a deliberate and cynical interference with the technical measures designed to protect immature fish."

"The evidence demonstrated the quantities of juveniles that may have escaped if the illegal device had not been fitted, an argument that was compelling and reflected in the sentence and forfeiture imposed by the court."