European plaice (Pleuronectes platessa
) is a widely distributed bottom-dwelling flatfish that inhabits the temperate waters of the Northeast Atlantic from the White Sea to the Bay of Cadiz most frequently at depths ranging from 0 to 50 m. Adults are usually solitary, burrowing into sandy and muddy habitat, and migrating seasonally between feeding and spawning areas. In this stock most females reach maturity by age 4 and trawl surveys during the spawning period indicate a maximum age of around 10. Spawning occurs in central English Channel between December and March usually at depths ranging from 20 to 40 m. A large number of plaice originating from Sub-area 4 (North Sea) and Division 7e (Western English Channel) migrate into Division 7d to spawn during winter. Juveniles in the first two years of life mainly inhabit nursery grounds in estuaries and semi-enclosed coastal areas before migrating to deeper offshore waters and recruiting to the fishery. Plaice feed on worms, molluscs and small crustaceans mainly at night; and they are preyed on by other fish, marine mammals and sea birds.
Landings of plaice in Division 7d (Eastern English Channel) averaged around 4 200 tonnes per year between 1980 and 2014, and discarding of mostly undersized fish has ranged from 30 to 40% of total international catch weight over the last three years. Plaice are mainly caught offshore by Belgian beam trawlers targeting sole (Solea solea
) and French otter trawlers targeting mixed demersal species. Most plaice caught (65%) during the first quarter of the year consist of spawning migrants originating from Sub-area 4 and Division 7e. France take the majority of the landings (50%), followed by Belgium (30) and the United Kingdom (20%). The status of the plaice stock in Division 7d has improved recently, with an increase in spawning stock biomass since 2008 and a decrease in fishing mortality since the mid-1990s.