Østersdyrkar Alf-Roald Sætre i Espevikpollen

Oyster farmer Alf-Roald Sætre of the Espevik dam

Oyster farmer Alf-Roald Sætre of the Espevik dam with a case full of oysters. As far back as the Middle Ages, oysters have been considered luxury food for rich Norwegians. A Norwegian law from 1276 states the following requirement, in a chapter on the fishing industry: "Fresh salmon and other fresh fish and oysters shall be purchased on the boats or on the docks but not from shops." (Ørjan Deisz)

Espevikpollen

OYSTER DAMS

The northern European oyster has been a popular food for thousands of years, and many countries, especially France, England and Holland, have long traditions of raising this shellfish. In Scandinavia it is first and foremost in Lim Fjord on Jylland that there has been large scale oyster production.

In Norway, the company "Selskabet for de Norske Fiskeriers Fremme" set up oyster farming several places along the coast during the 1920s. For many, this was quite a lucrative extra income. In Hordaland there was oyster farming from oyster dams at Tysnes during the previous Century (i.e. at Espevikpollen and Seløya), in Os, Fana (Kviturdspollen) and Lindås, as well as at Bømlo. The oyster plant at Tysnes was the first one; it was in operation already at the end of the 1800s. Continuing until today, it is only the Espevik dam atTysnes and the Aga dam at Bømlo that deliver oysters. Most of the production takes place in land-based tanks, but the mother oyster is collected from the dams. The oysters from Hordaland are used in the first instance only for consumption in this country.

Oysters are native to our coast, but they were more common in earlier times, when the sea temperature was somewhat higher. The biggest problem with oyster farming is that reproduction is affected if the water temperature falls much below 18°C. The best environments for oysters to live and grow up is therefore in small, protected dams where the water temperature can be warmer than in the open sea. 

The Pacific oyster has also become more established in Hordaland during recent years. This is a foreign species from America that is unwanted in Norwegian nature, but its spread is almost impossible to prevent. It is not known what consequence this will have for our own oysters or other indigenous species.

Ein typisk østerspoll er frå femti til nokre hundre meter brei og har ei trong og grunn opning. Aller best er det når det renn ein sildrebekk ut i ein slik poll, stor nok til at det øvste vassjiktet har lågare saltinnhald enn vatnet mot botnen. Ferskvatnet blandar seg lite med saltvatnet under og lagar eit stabilt brakkvasslag på toppen. Det skjermar sjøvatnet under frå kontakt med lufta. Om dagen trengjer solstrålinga gjennom brakkvasslaget og varmar opp sjøvatnet under. Ved avkjøling om natta skjer varmetapet berre frå overflata. Såleis fungerer brakkvasslaget som glaset i eit drivhus. Sjøvatnet under blir godt oppvarma, og temperaturen her kan bli over 30°C.

See also

Places in muncipality