Flat oyster, Common oyster

Flat oyster, Common oyster

Norwegian oysters have been popular for centuries; in the 1500s the Danish King sent boats to Norway to harvest them. Oysters are a good source of zinc, and are also rich in other important trace elements, like copper and iron.


Flat oysters are to be found along the Norwegian coastline, especially in the southern coastline of Skagerrak, as well as Helgeland.

Maximum size

Up to 15 centimetres in diameter.

Some alternative names

Latin: Ostrea edulis

English: Flat oyster, Common oyster

French: Huître plate

German: Auster

Nutritional value in 100 g raw oyster (edible part)

Energy: 247 kJ or 59 kcal



Protein: 9,3 g

Fat: 2,4 g

Saturated fatty acids: 0,5 g

Trans fatty acids: 0 g

Monounsaturated fatty acids: 0,5 g

Polyunsaturated fatty acids: 1 g

Cholesterol: 50 mg


Carbohydrates, in total: 0 g


Vitamin A: 38 RAE

Vitamin D: 3,1 µg

Riboflavin: 0,20 mg

Folate: 10 µg

Vitamin B12: 14 µg


Iron: 3,1 mg

Selenium: 60 µg

The most popular oyster in Europe is the European flat oyster, which is the only oyster variety naturally found in Norway. In addition, the Pacific oyster has been found along the south coast of Norway and in the country of Hordaland. The flat oyster is found in waters heated by the sun and in shallow waters northwards to Trøndelag. A water temperature of about 15 degrees is necessary for the oyster to change from male to female. The oyster builds up roe and milk from spring to the spawning period in the late summer, but only spawns if the temperature is high enough. The eggs are fertilized inside the shell, and the larvae stay inside the shell the first week before leaving the mother. When they leave, they swim freely until they attach themselves to the bedrock where they will remain. Larvae are also produced in hatcheries, or in a combination of hatcheries and oyster tanks.   The European flat oyster can live for more than 20 years, although the normal lifespan is between 8 and 10 years.


Norway harvests only small quantities of wild oysters, and these are harvested by divers or with rakes with landing nets. Oysters are in season year-round, but are considered to be at their best from autumn to spring.


Flat oyster is sold as following products:

  • Raw


Plankton, microalgae, organic materials


Oysters are especially rich in:

  • Protein that builds and maintains every cell in the body.
  • Vitamin D, necessary to balance calcium in the body, which maintains and strengthens the bones.
  • Vitamin B12, which is important for the body to produce new cells, including red blood cells. Vitamin B12 can contribute to preventing anaemia.
  • Selenium, an important element in an enzyme that fights harmful chemical processes in the body.

More nutritional data can be found at www.nifes.no/en/prosjekt/seafood-data