IntroductionofLarge Scale Open Water Aquaculture System

Nippon Steel Engineering Co., Ltd.

Copyright©2020 Nippon Steel Engineering Co., Ltd.. All Rights Reserved.

01. Concept
 This system consists of Feeding Platform, Subsea Pipelines and Submersible Cages.
 Features of this system are …
to enable farming in exposed sea by utilising underwater sea cages and feeding systemfrom platform.
to expand production by introducing larger cages.
(Conventional : 10m*10m*10m  50m*50m*20m)

to save labor by automation of feeding.

Feeding Platform

Subsea Pipelines

Submersible Cages

Automatic Feeding

Depth Control

Remote Control

Monitoring Device

Power GenerationCopyright©2020 Nippon Steel Engineering Co., Ltd.. All Rights Reserved.

12. Location
 Feeding Platform and Submersible Cage are installed by Nippon Steel Engineeringin the farms of Nippon Suisan Group and now under operation.
Feeding Platform@ Miho Bay (Tottori Pref.)Submersible Cage
@ Shibushi Bay (Miyazaki Pref.)Installed at Nov-2016
in Coho Salmon Farmof Yumigahama Suisan

Installed at Nov-2018
in Japanese Amberjack Farmof Kurose Suisan
Copyright©2020 Nippon Steel Engineering Co., Ltd.. All Rights Reserved.

2

3. Current R&D For further improvement of this system, we are now carrying out R&D projectin collaboration with other industry, academia and government under support from MAFF
(Ministry of Agriculture, Forestry and Fisheries).

* Industry(4) : Nippon Suisan, Kurose Suisan, Yumigahama Suisan, Nippon Steel Engineering, PanasonicAcademia(4) : Univ. of Miyazaki, Tottori Univ. of Environmental Studies, Univ. of Tokyo, Yonago CollegeGovernment(3) : Miyazaki Pref. Industrial Technology Center, Fisheries Research Inst. of Miyazaki Pref., Tottori Pref. Fisheries Research Center

Copyright©2020 Nippon Steel Engineering Co., Ltd.. All Rights Reserved.

3Product Profile: Large-Scale Open-Water Aquaculture System

Large-Scale Open-Water
Aquaculture System
1 Introduction: Background2 Large-Scale Open-Water

Factors

Aquaculture System

The production of seafood is expected to expand on theback of the continued growth predicted for the global
population, with demand for food also increasing in step.
Given that the harvest of wild-caught fish has plateauedinternationally, including in Japan, aquaculture production
will be needed to make up the difference (see Figure 1).
The sustainable development of aquaculture is an urgent
issue, with large-scale open-water aquaculture systems
being needed to form part of the solution.
(milliontons)

Aquaculture production
Seafood harvest

Figure 1 Global seafood harvest and aquaculture production(Source: “The State of World Fisheries and Aquaculture, 2016”,
United Nations Food and Agriculture Organization (FAO))

In a large-scale open-water aquaculture system, fish arefarmed in large quantities under conditions of high waves
and strong tidal currents. The system is made up of two
sub-systems: [1] Several large cages in which the fish areraised, and [2] Automatic fish feeding system (seeFigure 2).
In Japan, most aquaculture takes place in sheltered
coastal waters where waves are relatively small and with
better access from the land where it is easier to work.
Unfortunately, there is only a limited sea area suitable forsuch operations and it is recognized that such sites arelargely already taken.
Also, most coastal aquaculture operations are run byprivate farmers using small-scale cages (around 10 m ×10 m × 10 m), making them unsuitable for a large scale
production. In fact, the current situation raises numerous
concerns, including water pollution due to uneaten feed,excreted waste from the fish, and the consequent
problems with fish health, something that is exacerbatedby the slow circulation of seawater (or the low rate ofwater exchange) in inshore waters. Labor shortages areanother constant concern due to the need for experienced
workers and the hazardous nature of the workplace.

Layout of large-scale open-water aquaculture system

Large cage system

Automatic feeding system

Platform

Submarine pipe for feed supply

Feeders
CommunicationsPower generation

Large submersible cage
Raising and lowering mechanism

Typical feed mix

Monitoring system

Figure 2 Layout of large-scale open-water aquaculture system

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Product Profile: Large-Scale Open-Water Aquaculture System

In contrast, large-scale open-water aquaculture systems

cages need to be able to submerge below the surface of theuse large cages of 50 m × 50 m × 20 m and are intended forsea in order to withstand winds and waves that are more

offshore locations where there is a relatively fast flow ofsevere than in inshore waters.

water (it is assumed that a typical site would have a depth

To assess the effects of waves and water currents,of around 60 m and a maximum significant wave height ofnumerous simulations were conducted to analyze a wide

10 m). By enabling new developments in waters that havevariety

not previously been used for aquaculture (see Figure 3) andcomputational techniques. The results indicated thatthrough the use of measures such as automation to increase

performance would be adequate for open waterproductivity, these systems provide a large scale andenvironments, including that the required strength could

efficiency for corporate operators (see Table 1).

be achieved along with reliable raising and lowering of

Table 1 Benefits of large-scale open-water aquaculture system

submersible cages despite their size, approximatelyNewsites

Ability to withstand harsh seas and currents enables
operation in waters where aquaculture was not previouslypossible.

Scale

Production in bulk is achieved through the use of large cages
approximately 50 times the size of those used currently.

LaborsavingOperation with less or no staff is possible using technologies
such as automated feeding. This reduce wage costs andaddresses issues of labor shortages.

3 Technological Breakthroughofparameters

usingscalemodels

and50 times larger than those used currently. This technology
could possibly provide a pathway to higher fishproduction.
Automatic feeding system
In Japan, the conventional way of feeding is conductedusing feeding vessels and the fish are fed either by handor machine. In open waters, on the other hand, whereconditions can be extreme, the concern is that vessels may

Large cage system

not be able to access the sea for days at a time due to bad

The development of the large cage system drew on

weather and would interfere with the scheduled fish

Nippon Steel Engineering’s experience in technology forgrowth. To solve this problem, Nippon Steel Engineering

offshore structures such as oil and natural gas platforms.

has devised an automatic feeding system that uses aUnlike structures that are fixed to the seafloor, however,submarine pipeline through which fish feed can becages floating on the sea surface must be able to withstandsupplied directly to the cages. The system draws on thewave and current force. Furthermore, because Japan

company’s expertise in the conveyance of pulverized coal

experiences frequent natural events such as typhoons,at steel plants.

Existing coastal aquaculture

Large-scale open-wateraquaculture system

Source: Marine Cadaster, Japan Coast Guard

Source: Japan Weather Association

Set netfishing rights

Aquaculture
rightsFigure 3 Comparison of existing inshore range and new expanded range

82

Range where system can be deployed

Max. significant
wave height (m)Product Profile: Large-Scale Open-Water Aquaculture System

However, the pelletized feed used in aquaculture differsfrom the pulverized coal and could be easily broken
during long conveyance due to its fragileness. As this will
be wasted because the fish fail to recognize it as food, thebest way to transport the feed without damage is an issue
to be addressed. Furthermore, because the feed size
preference and the feeding behavior differs largely
between fish species, there is a recognized need to be able
to control the timing and rate of feed supply to suit thedifference according to the species. To determine theoperating conditions needed to satisfy these criteria forfeed transportation, a trial pipeline was built on land and

4 New Initiatives
Nippon Steel Engineering is now developing a production
management system (see Figure 4) that can provide an
optimal feed supply under various different conditions byusing underwater cameras and other sensors to perform
continuous monitoring of the farm environment and otherfactors such as fish growth and behavior (see Table 2). In
order to determine the best rate and quantity of feed,machine learning models will be achieved and applied toanalyze this data.
Table 2 Examples of data collected by production management
systemused to assess the disintegration rate for a variety ofdifferent feeds under different transportation conditions.
Thus, the optimal conditions for conveying feed wereachieved successfully.
This culminated in the successful completion of an
automatic feeding system made up of a submarine
pipeline and a platform on which the storage silos andfeeders were installed. The system contributes to higher
production efficiency and lower costs by supplying
enough feed without interruption and by lightening thehuman workload.

Environmental

Water temperature, current, wave height, dissolved
oxygen concentration, salinity, air temperature, hoursof sunlight, etc.

Fish growth

Fish count, weight, appetite, etc.

Feeding

Feed quantity and timing, etc.

This enables the feed quantity to be adjusted
dynamically based on factors such as fish growth andappetite, thereby reducing the feed conversion ratio (FCR),
the weight of feed administrated divided by increased fishweight, and significantly cutting the cost of feed, which
accounts for about 70% of production cost. This also may
turn the individual aquaculture skills into a common
resource that can be shared and passed on. These
outcomes should improve returns on investment and help
to transform aquaculture into a growth industry.

Figure 4 Production management system

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Product Profile: Large-Scale Open-Water Aquaculture System

5 Future Plans
Good progress is being made on preparations for theconstruction of the first commercial large-scale openwater aquaculture system through participation in thedemonstration project in Sakaiminato City, Tottori
Prefecture, the demonstration project in Owase City, Mie
Prefecture and the (still ongoing) project “R&D matchingfunds on the field for Knowledge Integration andinnovation” run by the Bio-oriented Technology Research
Advancement Institution of the National Agriculture andaquaculture as one of the initiatives for turningaquaculture into a growth industry. Beyond themodernization of Japanese aquaculture and its role as partof the country’s “sixth sector industrialization” lies agrand vision of meeting the public expectations of global
markets and contributing to the future of humanity.
Nippon Steel Engineering intends to take on the burden of
this vision and its associated responsibilities, and tocontinue its work on developing better aquaculture
systems.

Food Research Organization.
Awareness is spreading that the development ofpreviously untapped offshore waters represents a
breakthrough in aquaculture. Momentum for action isbuilding in both government and industry, one example ofwhich was the fisheries industry policy reforms being
undertaken by the Fisheries Agency identifying offshore84

For more information, please contact:
Aquaculture System BusinessDepartment
Business Solution Center
TEL (03) 6665-2638