HarbourFarm is farming in urban waters: the organic and sustainable production of fish, oysters and clams, combined with social and recreational activities in Copenhagen Harbour.
In recent years, the water quality in Copenhagen Harbour has improved radically- to the extent that residents are now swimming in the canals surrounding the parliament and enjoying beaches and waterfronts within the harbour.
The water in Copenhagen Harbour is now so clean, that farming fish, clams and oysters also is possible.
Oysters grow in special “cassettes” next to clams, who grows on ropes suspended under a pontoon on the surface. Oysters and clams breed from organic material in the water and at the same time, act to purify water.
Fish live among the cassettes and ropes feeding from organic material in and on the surfaces of the habitat, and in this way help to keep the growing environment clean and promote good water flow. The habitat has an artificial bottom and a net to contain the fish.
On the pontoon social activities and recreation take place, in a restaurant, where the harvested foods are enjoyed, and in activities like sailing, relaxing and education about harbour farming.
Electricity is supplied by hydrological turbines, windmills, and solar energy.
HarbourFarm monitors the overall water quality by running laboratory tests daily with results available to authorities and the public via the HarbourFarm website
When water is polluted from rain, broken drains or floods, the fish and shellfish are rendered inedible, but only so only as long as the water remains polluted. When water quality returns, so does edibility.
The oysters are local Danish oysters from Limfjorden (Ostrea Edulis). These are considered amongst the finest species of oyster. (95% of Danish oysters are currently exported for gourmet abroad!)
The life cycle of a full grown oyster takes approximately 4 years. It is possible to start growing the oysters in Copenhagen waters from any stage during this cycle- ie.: we will not have to wait 4 years for the first harvestable oysters.
One cassette contains 100 oysters. A floating construction of one square metre contains 9 cassetttes. ie. 900 oysters pr/m2
Oysters and clams need flowing water, but do not require light.
Oysters can be harvested all year.
Health authorities will approve water quality before harvests.