In European waters, there is currently a long-term program developing near-shore and offshore wind farms, to provide green energy for our growing demands. These inevitably take up considerable space, and operate with large exclusion zones around them. This gives rise to potential conflicts with other marine users, particularly fishermen.
One suggestion for optimizing use of the space and reducing conflict, is to permit the co-existence of aquaculture operations. Several studies have been undertaken by German researchers, but with no commercial interest of their ideas to date.
However, a recent study undertaken for the Shellfish Association of Great Britain (SAGB), “Aquaculture in Welsh Offshore Wind Farms,” has brought the idea a step closer to reality.
It looks at the species and techniques that would be feasible colocation partners for the renewable energy sector. Undertaken with European Fisheries Funding, the study offers suggestions and blueprints for both single species and multi-trophic aquaculture operations.
The study suggests that at present, the most economically viable candidate is the blue mussel. A small trial using seabed cultivation has already been carried out within the North Hoyle array by Welsh mussel company Deepdock Ltd, who showed that such an operation is both practical and viable, with no negative impacts on the wind farming operation.
The next step is to carry out trials using fixed aquaculture gear such as longlines, to assess how both the equipment and the service operation could co-exist with a wind farm in exposed conditions.
A number of other species were assessed for co-location potential, and considered to be promising in the medium term.
Experiments with the Pacific oyster and the European native oyster show that these species can grow well offshore, and that away from sites of spot pollution, disease loads and parasites are often reduced.
The report also refers to a survey carried out for the Irish and U.K. participant region of the Offshore Aquaculture Technology Platform (OATP), which suggested that Atlantic salmon, Atlantic cod and rainbow trout were suitable fish species to culture in offshore conditions in temperate waters.
This idea has now been picked up by The Crown Estate, which owns the majority of the seabed around the U.K. and issues leases for both aquaculture and wind farm operations. The organization recently offered a site off the coast of Cornwall (U.K.) for cultivation trials using rainbow trout in offshore conditions.
The SAGB co-location report looks in-depth at the cultivation potential of each species, along with production techniques, economics and markets, and possible operational issues. It further covers key aspects as licensing, leasing, legislation and policy drivers in Wales, and marine spatial planning issues throughout Europe.
Its recommendations include the formation of a co-location stakeholder forum capable of addressing technical assessments and protocol development, and the setting up of further trials.
The key to making it viable is to ensure that all sides understand each other’s operational needs and expectations. This is important as the sectors involved will have different aims and timescales, their financial characteristics will be poles apart, and there seem to be few advantages for wind farm companies in cooperating. However, a potential benefit for them is the public relations and corporate social responsibility spinoff, if they are seen to be maximizing use of a natural resource.
As the wind farm industry continues to develop, colocation could provide long-term opportunities for fish and shellfish farmers to expand beyond their current inshore operations. These are currently limited due to a lack of operational space, which is hindering the much-needed growth in aquaculture production in Europe.
If successful, there will be a need to ensure that any increase in production grows in tandem with market development, in order to avoid the boom and bust cycles we have seen too many times in aquaculture in the past.