Biology
The great scallop is the largest of the Norwegian scallop species. It is characterised by the shell, which has a yellow-brown/brownish gleam on the flat part, while the curved part of the shell is yellow-white. The species is widespread along the coast of the north-eastern Atlantic Ocean and in Norway from the outer Oslo Fjord to Nordland. Scallops are found from just beneath the intertidal zone down to a depth of more than 100 metres. In Norwegian waters, the greatest occurrence has been recorded at depths between 5 and 30 metres in Trøndelag and in Nordland. The scallop often lives partially buried in coarse sand bottoms, usually in areas with some current.
Scallops are hermaphroditic, and the roe sac lies in a bow in front of the muscle. The orange part constitutes the eggs, while the grey-white part is the milt. The spawning itself takes place during the summer half of the year, and the larvae swim freely in the water column before they attach themselves after more than a month to a firm substrate. When the scallops reach a size of 10–15 mm, they attach themselves to the bottom. It takes between 4 and 5 years before the scallops have become large enough to be harvested.
It is the water which transports food to the shells, and factors such as depth, tides and water movement affect the access of the shells to food.
Harvesting
The catch method for scallops in Norway is diving. Each scallop is picked by hand according to size. Through use of this catch method, careful treatment of the bottom fauna is ensured and that the shells have a minimum size of 10 cm. In other countries, dredges are used for the most part to catch scallops, but this method is little used in Norway because of unfavourable bottom conditions. A dredge takes with it everything that exists on the bottom, and it can harm other bottom-dwelling organisms, affect the environment on the bottom, damage the scallops and result in harvesting scallops that are less than 10 cm. Scallops are harvested year round, but they only have roe part of the year, and the time depends on the part of the country.
Research is being conducted on farming scallops, but is still at an early stage. Scallop farming has not commercial value for the time being. Farming of scallops falls under the category of sea ranching and is regulated pursuant to the Norwegian Sea Ranching Act.
Sustainability
The Norwegian Institute of Marine Research has previously conducted survey cruises to study the age composition in the stock in Trøndelag. The survey showed that both reproductive capacity and recruiting are good and vary little from year to year. This indicates that harvesting of scallops is sustainable managed.
Commercial fishing for scallops is limited to commercial fishers with registered vessels and crews. Catching scallops 10 cm in diameter is prohibited.
Some suppliers of scallops are certified by Friend of the Sea.
Food safety/quality control
The Norwegian seafood industry is subject to stringent requirements in order to ensure food safety. The control system consists of several bodies which jointly examine and monitor compliance with the requirements in all stages of the production chain. The bodies which supervise food are the Norwegian Food Safety Authority, the Norwegian National Institute of Nutrition and Seafood Research (NIFES), the Norwegian Directorate of Fisheries and the Norwegian Ministry of Trade, Industry and Fisheries.
Unlike other types of bivalves, scallops may be harvested outside areas classified by the Norwegian Food Safety Authority. Nevertheless, the same requirements are imposed for microbiological content as in bivalves from classified areas. Scallop producers must be able to document that the requirements are followed and that the scallops are safe to eat. The Norwegian Food Safety Authority conducts regular inspections of production areas.
Nutritional content
Scallops are lean food which is rich in:
- Protein, which builds and maintains all the cells in the body.
- Vitamin D, which is necessary for the right calcium balance in the body and which contributes to maintaining and strengthening the skeleton.
- Vitamin B12, which is important for the body's production of new cells, including red blood cells, and which can contribute to preventing anaemia.
- Selenium, an important element in the enzymes that combat harmful chemical processes in the body.
Applications/uses
The edible parts in scallops are the white muscle and the roe/milt or the gonads. Scallops may be eaten raw, slightly steamed, fried or gratinéed, and are ideally served in the shell.