Land-based aquaculture is increasing rapidly in Japan, where those interested in joining the sector have little choice because suitable ocean aquaculture sites in the country are mostly occupied.
Total aquaculture production in Japan has been fairly stable in Japan since the mid-1980s, at around 600,000 to 800,000 metric tons (MT), according to FAO statistics, and freshwater culture – mainly eels and carp – have been declining. Land-based salt-water aquaculture offers an opportunity for a new wave of expansion.
Three methods are primarily used: flow-through with seawater continuously pumped to the tanks; water-circulation, which requires a large separate bacteria purification and sterilization facility; and the biofloc method, which requires the careful culturing and maintenance of an ecosystem of bacteria within the tank feeding on the waste products of the fish.
A notable project in Japan is Tokyo-based Nissui’s biofloc facility growing vannamei shrimp in Minami-kyushu, Japan. The biofloc aquaculture system uses no purification equipment. The ammonia in the floc that forms in the tank is detoxified by nitrifying bacteria, stabilizing the water quality. Maintaining and growing the floc is a science in itself. Nissui imports specific pathogen-free (SPF) parent shrimp from the Oita Marine Biological Technology Center in Hawaii to avoid disease outbreaks (SPF does not mean there is no disease, but simply that the shrimp do not have specific diseases.) The larval shrimp are raised for 20 days until they weigh about one milligram each, then they are then transferred to an aquaculture facility in Minami-kyushu to grow for 3.5 months to about 20 grams. The company has been test-marketing the shrimp under the Shirahime Ebi (Snow White shrimp) brand, and will move to commercial sales in the coming fiscal year starting in April.
Maruha Nichiro, also headquartered in Tokyo, operates an inland fish farm in Yuza, Yamagata Prefecture (northwest Honshu Island) raising sakuramasu or “cherry salmon” (Oncorhynchus masou). The farming system, developed with Tokyo-based valve maker Kitz Corp., analyzes data such as water quality and temperature using a cloud-based system to automate feeding.
FRD Japan, Co., headquartered in Saitama City, has announced plans to scale up from a small hatchery facility for rearing trout in land-based tanks to a larger pilot plant in Chiba Prefecture, near Tokyo, with a target output of 30 MT of salmon per year. The company has developed a closed aquaculture system that recirculates artificial seawater (tap water with salt added) using a biological filtration system. The daily replacement rate of the water with new tap water is only 0.2 percent. FRD aims to complete a commercial plant in Chiba capable of producing 1,500 MT of sushi-ready salmon slices by 2020.
While the technologies for land-based aquaculture have been proven at pilot scale, the big stumbling block is the cost of equipment and of processing water and maintaining proper water temperature. The profitability of such projects is predicated on getting a premium price, due to freshness, live sales, or local preference. Claims of shipping-cost reductions by proximity to markets typically compare domestic production against air-flown fresh imported product—frozen ocean-shipped is still cheaper, even with duties.
In the past, this has meant that land-based aquaculture was only practical for expensive items such as blowfish. And while new technology and expanding know-how have combined to make these sorts of ventures more feasible, turning a profit on lower-value items like shrimp and salmon will still be a challenge. However, over time, such systems are expected to facilitate breeding for rapid growth, detailed testing of optimal feeding regimens, and labor-saving efficiencies that may help to equalize the costs. Land-based aqua-farming is still in its early stages and companies with deep enough pockets to bear the early costs are hoping to reap the rewards of being the first into what they perceive as a promising new industry.
Photo courtesy of Mitsui Co.
