Technological developments in Pacific oyster cultivation
The Pacific oyster, also known as the Japanese giant oyster (Magallana gigas) is one of the world’s most cultivated species. IVL Swedish Environmental Research Institute is currently testing submerged cultivation systems that combine the cultivation of Pacific oysters, native oysters and mussels.
The Pacific oyster came to Sweden in 2006 when larvae arrived on sea currents from Denmark. The species is now well-established in Swedish waters and populations continue to increase – in 2014 there were estimated to be about 250,000 tonnes in the landscape northern Bohuslän.
Although eradication of the Pacific oyster in Swedish waters is an impossible task, the authorities are responsible for the regulation of commercial activities that may increase the potential negative impact of the species. For this reason, cultivation of the Pacific oyster is banned, due to the risk of cultivated individuals contributing to an increase of wild populations through reproduction.
However, a variety of techniques exist that could enable the cultivation of Pacific oysters without contravening the ban, for example by using a submerged cultivation technology.
The benefits of submerged cultivation systems are many, these systems are virtually invisible, which minimizes conflicts with coastal landowners and boat traffic. In addition, the farms are less affected by icing. The quality of cultivated specimens is also higher, reproduction can be controlled, and stable production can be maintained all year round. Other benefits are reduced risk of disease and significantly less invasion by fouling organisms.
IVL tests and evaluates innovative cultivation methods that can enable the cultivation of, among others, Pacific oysters in Swedish waters and facilitate the expansion of current production levels of domestic oysters and mussels. The methods we evaluate involve techniques for fully submerged deep-water cultivation, a technique that can promote both the biological and socially sustainable development of the Swedish aquaculture sector, in parallel with the economic development of rural communities and Swedish tourism.
This would increase the availability of organic, locally produced and healthy mussels and oysters, as well as having positive environmental effects through the absorption of nutrients.