The Vessel Monitoring System (VMS) tracks the position of all boats over 12 metres long, allowing authorities to see where boats are every hour. This, coupled with electronic catch data, showed Marine Protection that the two French boats had been fishing illegally.

Arnaud Delalonde, owner and skipper of the fishing vessel Pescadore, and Tony Mesnage, skipper of fishing vessel Saltimbanque, were fined £30,000 by the Royal Court after admitting fishing within Jersey’s exclusive limit and misreporting fishing zones in their logbooks.

Pescadore was found fishing for scallops inside the exclusive three-mile limit during a night time operation, and officers used satellite tracking and other electronic data to establish that both Pescadore and Saltimbanque had fished inside the three-mile limit on a number of other occasions.

Dave Yettram, Senior Marine and Fisheries Officer, said: “We have caught a number of boats fishing in the exclusive zone before by using a combination of VMS and radar, but this is the first time we have been able to prosecute boats by using satellite monitoring and electronic fishing records.

“This sends a strong message out to other fishermen that if they enter the exclusive zone, thanks to this technology, they are likely to be caught.”

Jersey began using the satellite monitoring data three years ago. Until then marine protection officers had to chart the position of boats manually using latitude and longitude positions.

In 2010 Marine Protection caught a French boat trawling in a prohibited zone north of Jersey, and in 2011 they tracked a local boat that was too big to fish in the exclusion zone,

Dave Yettram said: “We can now see where boats are very easily on the chart. Thanks to this sort of technology, the days of boats being able to sneak into exclusion zones at night are probably over.”