Some facts about shrimps

The North Sea shrimp comes from the Wadden Sea and the North Sea. Its scientific name is 'crangon crangon', and it is also known as the grey shrimp, brown shrimp or Dutch shrimp. The Dutch shrimp belongs to the Crangonidae, or sand shrimp, family. There are around 1,950 different shrimp families, 300 of which are commercially caught for consumption. With annual supplies of 25,000 to 35,000 tons, the Dutch shrimp is among the top ten of commercially important shrimp species.

Although the name suggests otherwise, the North Sea shrimp can be found in inter-tidal sand and mud sediments in shallow coastal waters along the entire Western European coastline and in the Mediterranean Sea. During the day the shrimp burrows into the sediment, leaving only its eyes and antennae protruding from the burrow. At night its colour darkens, acting as camouflage when the shrimp comes out from the burrow to eat algae, snails and vegetation.

Typically, the shrimp spends the early part of its mature life as a male; once it has mated it passes through a short transitional phase before subsequently spawning and maturing as a female. Some juveniles, however, never mature into males; instead they develop directly into females. The females spawn two to three times a year, carrying the eggs for several months at the posterior end of the abdomen. As the time for spawning approaches, the shrimps become sensitive to temperature fluctuations, and begin their migration to the North Sea, where they spawn between 2,000 and 12,000 eggs a year.

The larvae, which are no longer than 2 mm, are carried by the current towards the Wadden Sea. They develop during this period and become bottom feeders when they reach approximately 5 mm in length. They are fully mature at 6 months.

The Wadden Sea, North Sea and Zeeland coastal waters are the major harvesting areas: closer to the coast during the summer, when the waters are warmed by the sun, and further out to sea in the winter, where the waters retain warmth. Shrimp are harvested throughout the year, with clear seasonal peaks in April and May and in the autumn. Shrimp levels vary from year to year, and sometimes from season to season.

The shrimps are washed and cooked as soon as they are brought on deck. The cooking equipment is powered by diesel from the engine overflow. The shrimps are cooked for between 3 and 6 minutes, afterwards they are actually edible. The colour of the shrimp changes during cooking from grey to reddish pink, and it gets a curved shape. After cooking, the shrimps are cooled and stored.

The fishermen are not the only shrimps’ predator, they also form the diet for many other fish predators in the Wadden Sea, such as dab, cod and whiting.