FEATURE | Semi-submersible mussel farm concept for offshore waters
Dutch engineering company OOS International, through its OOS SMF division, has partnered with local research non-profit Deltares on the development of a new type of semi-submersible mussel farm (SMF) for deployment in the North Sea and other offshore areas.
In collaboration with the Dutch shellfish sector and mussel farmers, OOS SMF developed the SMF, which is suitable for growing mussels based on hanging culture at open seas. By applying submersible technology, the breeding and harvesting location in open seas will be protected against waves and storms. A suitable location in deeper waters can be used for the large-scale cultivation of mussels.
A proven offshore design
The design philosophy of the SMF is based on the floater/column design of the semi-submersible offshore construction and accommodation vessels OOS Serooskerke and OOS Walcheren, enabling the SMF to be operated safely even in harsh environments at sea.
The project team decided upon the deployment of examples of the farm in and around offshore wind sites as a viable means of ensuring continued production of mussels in the face of declining numbers in traditional sheltered areas. Mussels are traditionally grown in sheltered waters such as the Oosterschelde in the Netherlands. However, the production of mussels in these areas is declining rapidly due to changing regulations and environmental/physical influences.
OOS said growing mussels at sea is therefore regarded as the most viable solution to maintain and increase production and is also aligned with the current developments in the food transition, reducing CO2 emissions while creating a better and new environment for sea life.
Testing of a physical model of the farm will be conducted next year at Deltares’ facilities in Delft. A real-time pilot test, for which the Dutch government has already issued a permit, will also be undertaken at the Borssele offshore wind farms.
Plans for future widespread deployment
OOS said that based on the results of the model test and the real-time pilot, the final semi-submersible unit will be developed and taken into production in collaboration with mussel farmers, processing companies, and trading companies. OOS expects multiple mussel farmers will be able to use the SMF simultaneously.
The first SMF, which will be named OOS Cees Leenaars, will measure 76 by 32 metres and will be fitted with wind-, solar-, and tidal current-powered charging stations for use by the supply vessels that will collect the harvested mussels and transport them to shore.
The project partners hope to have numerous SMFs in operation off the coast of the western Dutch province of Zeeland.