Seabed fish farms – a cleaner, cheaper way to get fish on our plates
Over half of the fish we eat globally comes from wild fishing. The result is pressure on fish stocks and consequent impacts on biodiversity. Aquaculture is the most promising option to mitigate overfishing and meet the increasing demand for protein. In 2015, Europe imported 74.6 % of the fish eaten, so boosting European aquaculture to increase our self-sufficiency is also a central goal. “The solution,” explains project coordinator Kenneth Winter, based at Marine Garden in Norway, “requires measures such as moving further offshore and the farming of new species, without placing unacceptable demands on ecosystems.”
Ever-increasing need for protein-rich foods
Currently fish farms are mainly placed in near coastal spaces and on the sea surface. This is done to minimise weather and wave impact and facilitates access to the fish stock for feeding, treatments and retrieval. As coastal space is limited, the aquaculture industry has to scale up and move into offshore environments in the open sea. “The sea is a different animal when you move away from the coast,” says Winter. He explains that attempts to build vast, oil-platform-like farms are in progress. But these constructions are massively expensive to build and will not be able to feed the next billion as our population increases. The EU-supported SUBFISH project is looking at subsea solutions. “Underwater you don’t have to fight with natural forces as much as on the sea surface: no wave and wind impact, no icing in winter, no UV exposure in summer,” Winter says. This means a drastic reduction in the amount of materials used and makes the process much cheaper.
Expense of traditional fish farms drives higher stock density
Current sea fish farming solutions are capital intense: they have to be robust and large enough to withstand the natural forces which are significant on the sea’s surface. “The density of fish stocks goes far beyond what is natural. It has to be high for the farms to be viable. This creates a pandemic environment, so medicines and other chemicals are used. There is another problem: parasites. Sea lice are a very costly problem for traditional fish farming industry.” SUBFISH selects species that thrive on the seabed. The system doesn’t set out to ‘stand up to nature’ but to work with it. Winter explains: “Our structures are flexible and use forces of nature (buoyancy and flexibility) to preserve their shape underwater.” Feed is eaten before it can drift away and, as the fish live too deeply to be impacted by lice, there is far less need for chemicals. “We are the only aquaculture company which has been given permission to operate in pristine waters of Siquijor Island, in the Philippines,” Winter says proudly. Marine Garden is now in dialogue with authorities in the Canary Islands, where Macaronesian Grouper would be an ideal species to farm. They are also talking to authorities in the Azores. “We hope to be able to generate 23 jobs in these three sites alone,” adds Winter. The team is now looking to grow their operation in the Philippines and serve more of their target market of 350 million Chinese.
SUBFISH, aquaculture, marine, overfishing, biodiversity, food, fish farming, Marine Garden