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Plaice

size:

up to 100 centimeters, usually much smaller

weight:

up to 7 kilograms, usually much less

color:

topside grayish brown with orange spots, underside gray

age:

up to 15 years

food:

worms, shellfish

movement:

swims

enemies:

people, seals

reproduction:

sexual

  • Dut: Schol (bunscholleke, kantschol, keu, kraat, plaat, pladijs, ronde schol, spreischol)
  • Lat: Pleuronectes platessa
  • Eng: Plaice
  • Ger: Scholle, Goldbutt
  • Fren: Plie, Carrelet
  • Dan: Rødspætte
Plaice, foto fitis, sytske dijksen

Plaice

Plaice is probably the best known fish species in the North Sea. Most people are familiar with this flatfish, even if it's just from eating it. After sole, plaice is the most consumed fish species in the Netherlands. This fish has notable orange spots on its body. Despite these spots, it is hard to see them lying on the bottom when they are buried halfway under the surface. Just like most other flatfish, plaice have both eyes located on the right side of their body. They make a wavy movement when they swim, which gives them an extra push from the water, which rebounds against the sea floor.

  • Development of the plaice stock
    Spawning stock and yield of plaice (North Sea), Ecomare

    According to the International Council for the Exploration of the Seas (ICES), there is much more plaice found in the North Sea nowadays. The number of adult plaice has been increasing in the past few years. Biologists estimated 523,000 tons in 2011. That is the highest number in the last 50 years. The mostly likely explanation for this good news is the decrease in the fishery pressure due to reorganization of a section of the fishing fleet. The plaice stock seems to be recovering from the dramatic decline which took place between 1987 and 1999. In 2003, the fishery biologists agreed to lower the safety level for plaice from 300,000 tons to 230,000 tons of adult fish.

  • Plaice fisheries
    Plaice, ecomare, sytske dijksen

    Plaice can be fished in many ways. Most plaice in the North Sea are caught with beam trawls with tickler chains. Twinrigging, electro-fishing and sumwing are fishing methods that cost much less energy and can result in good plaice yields. The Danish coastal fleet catches plaice with purse-seining. Plaice is the traditional specialty for the large cutter fleet in Urk. The majority of the yield is exported as frozen filet.

  • Protecting nurseries

    Plaice spawns in the southern North Sea. After the eggs hatch, the larvae are carried with the sea current. Eventually, the young plaice end up in the Wadden Sea, where they profit from the richness in benthic animals on the mudflats. They are particularly fond of shellfish siphons, the tubes shellfish such as cockles use to suck in and discharge water. The hind end of worms is also a favorite. After several years, the fish continue their life in the North Sea

    In order to protect young, undersized plaice better, a plaice box was established in 1989. This region, around 40,000 square kilometers north of the Dutch and German Wadden Islands and west of the Danish Wadden Islands, is closed the entire year to beam trawlers with a motor capacity greater than 300 hp. In the meantime, it has been shown that young plaice hardly profit from this measure, which is why the plaice box is now under discussion.

  • Earlier maturty due to fisheries
    Plaice, Ecomare

    In the 1950s, female plaice were sexually mature between the lengths of 27 to 41 centimeters, at an age between 3 and 7 years old. Because the fisheries have removed the large plaice, smaller plaice have more chance to produce at a younger age. Nowadays, female specimen turn adult at a length between 25 and 37 centimeters.

  • Distribution and habitat
    Spawning and nursery grounds of the plaice, Ecomare

    Plaice is found in coastal waters of Iceland and southwestern to northern Europe. 75% of the North Sea plaice grow up in the Wadden Sea.

  • Long-distance travelers

    Plaice migrate in severe winters to places where the sea remains warm. Around 1995, a British research team marked plaice with electronic equipment in order to register their migrating behavior. Their data showed that plaice travel long distances. One fish had traveled 900 kilometers within 56 days. For this kind of long voyage, the plaice make use of tidal currents: they swim to the upper water layers with a current flowing in a favorable direction and drop to the bottom when the current turns unfavorable.