Scottish fishermen are pioneering a scheme that will reward skippers for catching fewer cod, sole and plaice in their nets when they go after other species.

Under the pilot, skippers will be granted extra days at sea if independent observers on board their trawlers conclude that the bycatch of endangered species is less than 5% of the total catch on any fishing trip.

Scotland is thought to be the first nation to take advantage of the measure, which was introduced by Brussels last winter as part of the EU's recovery plan.

"This scheme will reward Scottish skippers who are able to use their expertise to avoid cod," said Richard Lochhead, cabinet secretary for rural affairs and the environment. "It is essential to harness the skill and knowledge of fishermen in order to allow other forms of fishing with minimal by-catches of cod."

The scheme relies on observers costing about £175 per day, and has been made possible by funding from the Scottish Government.

The aim is to determine how effective the arrangements are and to demonstrate to fishermen that the cost of an observer is outweighed by the potential fishing benefits. "We have managed to secure 100 days of observer time," said Scottish Fishermen's Federation chief executive Bertie Armstrong.

"It is an example of the industry stepping forward and showing it's committed to catching less cod."

The industry is also turning to a raft of other voluntary stock management measures in an effort to demonstrate how serious they are about managing Europe's cod stocks. Langoustine trawlers increasingly use fish-friendly nets.

Another key measure is the temporary closure of fishing areas where high concentrations of young cod are detected.

"Boats report the find so the area can be closed, then they move away and fish elsewhere," Armstrong said.