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Offshore fish farming: Food for thought

Offshore fish farm

-- FROM THE FULL PICTURE MAGAZINE --

With a growing population and dwindling availability of arable land mass the world needs to solve the food production challenge. Ocean Farming believes the answer might just lie offshore …

The world is hungry for innovation in food production. By the year 2050 it is estimated that there will be 2.3 billion more mouths to feed, requiring a leap in production levels of some 70% compared to the present day. Satisfying that demand requires a fundamental step change, but which way can society turn?

Gunnar Myrebøe thinks it's time to look to the ocean.

Gunnar Myrebøe

Gunnar Myrebøe
COB, Ocean Farming

The full picture according to Ocean Farming
For the future of mankind, we need to look out to sea. Ocean Farming believes we can’t see the full picture if we focus food production efforts on land. Only 2% of the world’s caloric intake currently comes from the oceans. By embracing new offshore solutions we can satisfy the hunger of billions more mouths.
 

Myrebøe, a veteran of the energy industry with Norwegian firm Statoil, is COB at Ocean Farming, a subsidiary of SalMar ASA. Ocean Farming was set up three years ago by Gustav Witzøe, the founder and principal owner of SalMar, in response to the increasing need for fish protein and nutrition. The firm has hit upon a big solution for this big issue, combining technology from the fishery, fish farming and offshore industries for a project that has the potential to revolutionise the aquaculture industry.

Piloting the future

"Fish are some of the last living creatures we still hunt in large quantities in the wild," states Myrebøe, adding: "We have to change the way we think about fishing and make use of new ocean territories in order to meet future demand for nutrients and feed a growing world population. According to the Food and Agricultural Organization of the United Nations, the production of seafood has to increase, primarily through aquaculture."

There's nothing new about aquaculture, but there is about Ocean Farming's vision. The firm is awaiting construction of a full-scale pilot project that is unlike anything the industry has ever seen. Large enough to fit an entire offshore platform inside, with the capacity to raise 1.5 million fish annually, and moored far from land in an exposed environment, its submerged ocean fish farm would be science fiction, if it wasn't very soon to be science fact.

"We hope to start operating in 2017, provided we get the necessary concessions," Myrebøe reveals. He describes the project as "an enormous research facility," where the initial focus will be on ensuring "the proper functioning and stability of the facility, and to maintain the welfare of the fish." The data it collects will be crucial in underpinning the further development of ocean fish farms.

The best of both worlds

Myrebøe depicts the company's ocean fish farm as a submerged/ floating facility designed much like an offshore rig, secured by anchors and tethered at depths of between 100 and 300 metres. Global Maritime AS has performed the technical design and engineering, with MARINTEK involved in a basin model test to ensure suitable behaviour in harsh weather conditions. DNV GL was brought in to verify design work through an independent review process.

"We have to change the way we think about fishing and make use of new ocean territories in order to meet future demand for nutrients and feed a growing world population."

Gunnar Myrebøe COB,
Ocean Farming

KONGSBERG was selected for the project due to the strength of its unique combination of experience as a supplier to the maritime, offshore and fishery industries. Systems from KONGSBERG will include sensors and echo sounders for real-time visualisation of fish distribution in order to monitor such factors as fish biomass, position and escape.

Communication systems for data transfer to shore, automation and navigation systems, project management and EIT will also be provided as part of the firm's integrated ‘Full Picture' solution.

"All of the key suppliers involved in the fish farm are driven by tremendous enthusiasm and a sense of prestige, which are the best control parameters in my opinion. We searched for suppliers who were the best equipped to drive the project, and who would be able to provide the technology needed to run this facility in the future. KONGSBERG has a proven record as a supplier to the offshore oil industry and is recognised for high image quality in its subsea products. Among other things, we use sensors from KONGSBERG to measure the size of the fish to determine which are ready to be harvested," explains Myrebøe.

A farm on the fish's terms

Critics have voiced concerns about environmental and health issues related to fish farming, and the industry is working hard to resolve these issues. For instance, placing the facility offshore gives biological conditions more suitable for aquaculture on the ‘fish's terms'. Running a successful offshore fish farm is dependent on finding locations with a natural supply of fresh water, such as Frohavet, where the Gulf Stream passes through. The pilot will be located here, and despite waves of up to 8-10 metres, the huge facility is designed to remain completely stable.

"One of the challenges when a fish farm is placed in a fjord is that the tide washes the same water in and out around the facility," Myrebøe relays. "This causes problems with lice, since the same population of lice is simply flushed back and forth. In an offshore facility placed in the ideal location, the water passes through the cage and washes away lice and other pollutants, giving the fauna a habitat as close to natural as possible."

Although lice are a natural part of ocean fauna, they can be damaging to fish in large quantities. With this in mind, other methods are also being tested to avoid infestation.

"By releasing larger smolt into the facility, the risk of contracting disease is reduced along with the life cycle. Another technique we use is to feed the fish 10 metres below sea level, forcing them to submerge. This reduces the risk of catching lice, since lice live close to the surface. It is also important to place the farms so that water from one facility does not wash into other nearby facilities," Myrebøe states.

Fully automated

All farming operations can be managed either on board or remotely, minimising the use of service vessels and outside equipment, and thus making the entire facility more environmentally friendly. This means the fish can stay inside the net from initial stocking through to the point where they are harvested. The facility can also be divided into three separate compartments if needed, enabling various parallel operations.

The net is fixed to the structure and is specially designed to pre- vent fish from escaping. In addition there is an extra net in the surface zone to protect against drifting matter. Regular cleaning of the nets is accomplished through the use of automated spray nozzles. Since the facility is fully automated, heavier manual operations are avoided, and a crew of only two to four can run the entire facility.

"There has been a lot of interest in working on the farm," Myrebøe divulges. "We are aiming to have three people on board at all times, combining competence in biology, electro and instrumentation. The staff will be trained much like offshore staff, including emergency preparedness courses."

Fish farming facts

Towing fish farm
  • Diameter: 110 m
  • Height: 67 m
  • Volume: 245,000 m3
  • Salmon: > 6,000 tonnes

Low operational costs

While a comparable fish farming facility today has a price tag of approximately NOK 50 million, an ocean farming facility will have a significantly higher investment cost, raising questions of profitability. However, since operational costs are expected to be lower than traditional fish farming facilities, offshore farms may prove to be more profitable in the long run.

Myrebøe explains more: "If the fish are doing well, they will grow faster, meaning larger fish at harvest. Using more advanced surveying systems to monitor the fish and the environment on the fish farm will also help control costs. In addition, operational costs are lower since most processes are automated and only three people are required to operate the facility. Maintenance costs are also lower, as maintenance work can be completed faster. The rig will be deballasted out of the water to facilitate inspection by experts. The entire operation can be completed in just one week."

Sustainable resources

There is little doubt that this enormous construction, if put into operation, has the capacity to streamline the future of the fishery industry. The world needs more fish protein, and with the enormous resources that Norway's long coastline offers, it is expected to take a leading role.

"It is important for the future of the world population that this project succeed, and I don't see why it shouldn't," Myrebøe concludes.

"The world's oceans represent more than half the earth's biological diversity, and fishery is incredibly sustainable, but only 2% of our caloric intake comes from the oceans. This makes the sea an obvious resource for feeding more people. The Norwegian government has set a goal to increase fish production from one million to five million tonnes by 2050. If we are to meet this goal, it's time to start thinking differently and put those intentions into action."

"It is important for the future of the world population that this project succeed, and I don't see why it shouldn't."

Gunnar Myrebøe COB,
Ocean Farming

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