Method of production - Caught at sea
Capture method - Seine net
Capture area - North East Atlantic (FAO 27)
Stock area - Skagerrak
Stock detail - Subdivision 20
Fish type - White flat fish
Plaice is a long-lived species and subject to high fishing pressure. The state of the stock in this area is unknown and advice is that landings from the Western component of the stock should be no more than 6287 t and that in the depleted Eastern Skaggerak, no directed fisheries should occur. The most sustainable choice of plaice from this area is fish taken in directed seine or gillnet fisheries or by small coastal vessels from the Western area only. Avoid eating immature plaice below 30cm and during their breeding season, January to March.
Plaice is a bottom-dwelling flatfish. It spawns in the early months of the year (January to March) and sometimes makes long spawning migrations. North Sea plaice reach between 35 and 45cm in their 6th year. It is a long-lived species, becoming sexually mature at 3-7 years (females) 2-6 (males) and living 30 years or more. Maximum reported age 50 years.
The plaice stock in the Skagerrak consists of an Eastern and Western component. The latter is closely associated with the North Sea stock. Catches in the Western component normally constitute at least 90-95% of the total catches. For the first time in 2012 ICES advised on plaice for the Skagerrak separately. There is insufficient information available to evaluate the stock, hence stock status and fishing mortality are unknown. The two components of the stock show different trends in biomass - a 17% increase in the Western and a 70% decrease in the Eastern component. Fishing mortality is unknown, but effort has been substantially reduced. Scientific advice is that catches in 2015 should be no more than 7,232t. If discard rates do not change, this implies landings from the Western component of the stock should be no more than 6287t (8972 t in 2014). For the depleted Eastern Skaggerak, no directed fisheries should occur and bycatch and discards should be minimised.
No specific management objectives are known to ICES.
Plaice is caught all year round with a predominance from spring to autumn. In Skagerrak, plaice is taken both in a directed fishery and in a mixed fishery with cod, Nephrops, sole and plaice, especially with trawlers with 90 mm mesh size. Most plaice in the Skagerrak are caught by a directed small-scale fishery operating with seines and gillnets. Nearly all catches are now taken in the western area, while bycatch in Nephrops fisheries in the Eastern area have dropped to very low levels with the increasing use of more selective fishing gears. Discards are estimated to be low. Of a total catch of 7.9 kt in 2013, 86% was landed and 14% discarded. Of this total catch, 46% is fished using demersal seine; 32% demersal otter trawl; and 9% beam trawl. Danish fleets are prohibited from landing female plaice from this area between January and April. Bottom trawling can cause damage to the seabed in sensitive areas. The minimum landing size for plaice in EU waters is 27cm. The approximate size at which 50% of females mature or first spawn is around 30-34cm. Seine netting causes less disturbance to seabed than demersal otter or beam trawling.
ICES Advice 2014, Book 6 http://www.ices.dk/sites/pub/Publication%20Reports/Advice/2014/2014/ple-skag.pdf
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