Fisheries minister Richard Benyon has hailed the success of a Defra trial that cut discards at sea from between 28% and 38% of catch to just 0.2%.
Under current EU rules, fishermen can only land fish included in their quota. Any over-quota, non-quota and undersize fish are discarded over board.
But during the trial, which involved North Sea cod trawlers and Western Channel sole beam trawlers, discarding of target species including juvenile fish was prohibited.
The overall low quantities of undersized fish caught showed it was possible to reduce discards if fishermen made effective use of selective gear and avoidance methods, Defra said.