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Dieren en planten

Decapods   Prawns and shrimp   Brown Shrimp   Prawns   Fauna in tidal areas   Fish   

Brown shrimp

size:

up to 9 centimeters long

color:

transparent gray with spots, brownish pink when cooked

age:

2 to 5 years

food:

omnivore, also carrion

enemies:

flatfish, young seals, birds, shrimp fishermen

reproduction:

sexual

peculiarities:

only 1 out of 50,000 shrimp eggs reaches the adult stage. The rest are either eaten or die due to other reasons.

  • Dut: Gewone garnaal (grijze garnaal, Noordzee garnaal, gernaarts (B), geernaars (B))
  • Lat: Crangon crangon
  • Eng: Common shrimp (brown shrimp)
  • Ger: Sandgarnele (Granat, Krabbe, Nordseegarnele, Garnele)
  • Fren: Crevette
  • Dan: Hestereje (sandhest)

Brown Shrimp

Shrimp are found in large amounts in the coastal zone and tidal waters because they are well adapted to the strongly fluctuating circumstances. They are omnivores and profit from the rich supply of small animals. However, they also eat dead plants and animals, as well as excrement. They are very mobile and therefore can easily move to where the most food has gathered by the flowing water. When the temperatures drop, they move to warmer, deeper water. Many large marine animals and people are shrimp consumers.

On Texel


Shrimp catching, foto fitis, sytske dijksen

Lots of shrimp are caught around the island. As a tourist, you can book a trip on a shrimp boat leaving from the harbor of Oudeschild and experience what shrimp fishing is all about.

  • The hunter is hunted
    Shrimp with fish, Sytske Dijksen, www.fotofitis.nl

    Shrimp are omnivores, as long the food is available on the sea floor. They eat lots of small marine animals and munch on burrowed shellfish. Even young flatfish are not safe for a hunting shrimp. Seaweed, remnants from dead animals and excrement are also on the menu. Together with crabs and starfish, shrimp keep the sea floor clean.

    However, shrimp are tasty themselves and not just for people. All kinds of marine animals, such as fish, larger crustaceans and birds have shrimp on their diet. There is an estimated 160 billion shrimp in the Dutch coastal waters and tidal regions. Fishermen catch 8 billion annually and the shrimp consuming marine animals are good for 70 billion. That makes shrimp an important link in the food chain in the coastal zone. If the shrimp have a difficult year, changes are felt throughout the chain.

  • Day and night
    Shrimp, burrowed in the sand, Sytske Dijksen, www.fotofitis.nl

    Shrimp dig themselves in during the day. They hide in the upper layer of the sandy bottom. They appear when it gets dark. They hunt for food by chiefly following spores of odors and movements. Being nocturnal, they stay out of reach of predators that hunt by sight, such as dab, ducks and gulls.

  • Back and forth
    Shrimp, feeding, Sytske Dijksen, www.fotofitis.nl

    The sea transports large quantities of material in the shallowest part of the coastal zone with the waves. That's where fish excrement and dead or less mobile animals are also found. That is a buffet for shrimp; however they must constantly swim after their food. No problem - they are very fast.

  • Warm and cold
    Eye to eye, Sytske Dijksen, www.fotofitis.nl

    Shrimp are quite critical when it comes to temperature. They don't like water colder than 6 degrees Celsius. Land cools off more quickly in the winter than the sea. Shallow coastal water is influenced by land temperature and is colder than water further away from land. Shrimp move in autumn to deeper and warmer seawater. The temperature difference determines just how far they must migrate. In severe winters, they can be as far away as 90 kilometers. Because they are accustomed to looking for food in the dark, they have no problem surviving in deeper water. They start returning to shallower waters in March; after a severe winter, that will be even later.

  • Young and old

    Shrimp lay eggs. The female protects the nest, which contains between 1000 to 3000 eggs. She pushes the clump of eggs against her belly until the larvae crawl out of the eggs. These larvae first float around in the water, as zooplankton, before sinking to the sea floor. During this stage, they are in great risk of being eaten by all kinds of other plankton feeders, such as young herring or the larger copepods. The majority of the larvae don't survive to grow into adults. In order to compensate this loss, adult shrimp produce eggs around three times a year. Shrimp don't get very old. Three years is already a respectable age.

  • Hiding
    shrimp, close up, sytske dijksen, foto fitis

    Shrimp are camouflage artists. Their shield is semi-transparent with grayish brown spots, allowing the color of the underground to shine through. The animal can adapt the pattern of the spots to the structure of the underground: the cells containing the brown coloring can be expanded or contracted. Consequently, shrimp are practically invisible on a sandy bottom. Furthermore, shrimp probably have another method for hiding. They are constantly making a rustling sound. When you realize that many fish follow sounds when hunting, the shrimp produce a kind of mist made up of sound so that the hunters can't hear exactly where the shrimp are actually located.

  • Shrimp consumers
    Food web around brown shrimp, Ecomare

    Dab is the champion shrimp consumer, the most prominent flatfish found in the southern North Sea. Lesser sandeel, a small benthic fish found in large quantities in the North Sea coastal zone, have also specialized in catching shrimp, just like other small benthic fish such as eelpout, butterfish and gobies. Young whiting and cod also feed a lot on shrimp. Danger from above comes from ducks and gulls. And should you wonder what crows are doing on the beach: looking for shrimp. All together, these animals consume 70 to 80 billion shrimp in the Netherlands.

  • Shrimp fisheries
    Shrimp vessel, Sytske Dijksen, www.fotofitis.nl

    The shrimp fisheries are one of the most important activities of the Dutch fishing fleet. Shrimp are caught with small to medium-sized vessels. The catch is boiled on board and sold on land to companies which control the peeling and trading. You need a fine-meshed net to catch shrimp and you catch lots of other marine mammals as well. This bycatch was a major problem for a long time, until a sorting machine was invented which is capable of sieving the catch rapidly. Young flatfish and other marine animals that are larger or smaller than shrimp are returned back to sea still alive.

    The fishing gear of a shrimp vessel rolls over the sea floor. It disturbs the bottom much less than heavy tickler chains, which are used for fishing flatfish. Nevertheless, there are indications that shrimp fishermen disrupt the establishment of vulnerable benthic marine animals. That is why extra sensitive regions in the North Sea coastal zone have been closed for shrimp fisheries. The fishermen and the government are working on a gradual switch to more environmentally friendly fishing techniques.