Tuna farming start-up Next Tuna, which aims to be the first company in the world to produce its own Atlantic bluefin in a closed aquaculture system at a commercially viable scale, has progressed from setting abstract goals to solidifying construction dates within the past few weeks.
The company's’s research partner, the Murcia Oceanographic Center of the Spanish Institute of Oceanography, (IEO) which itself is part of the Spanish National Research Council (CSIC), recently closed the reproductive cycle of Atlantic bluefin (Thunnus thynnus) in land-based facilities – a world first. The successful closed-cycle breeding of Atlantic bluefin tuna means Next Tuna can progress its plans to construct a farm at a location north of the Spanish city of Valencia.
On 13 July, 2023, one of IEO’s Atlantic bluefin breeding stocks at its ICRA facility in Cartagena underwent hormone treatment to induce final maturation and spawning, both phases of which can elicit complications due to the stress of captivity.
Previously, industry experts had only closed the biological cycle of this species of bluefin in floating sea cages.
With land-based closed-cycle breeding achieved, IEO is now working with Next Tuna, which receives funding from both the European Union and EIT Food, on other aspects of rearing Atlantic bluefin juveniles. This includes feeding – a stage the group recognizes is key in relation to the economic viability and sustainability of tuna farming.
Next Tuna will draw on the latest scientific developments in Atlantic bluefin breeding and apply them in a fully controlled, floating recirculating aquaculture system (RAS) production facility. Commercial production is slated to begin in 2024 and gradually increase to full capacity by 2028, with the company looking to produce Atlantic bluefin from first feeding to a 10-kilogram transfer size.
The concept is not unlike how the salmon-farming industry produces smolts in RAS systems, though tuna breeding results in much larger fish.
Since having its own broodstock and breeding program in place is an essential part of Next Tuna’s strategy, the IEO breakthrough represents a key milestone, company co-foudners Paul-Daniel Sindilariu and Andrew Eckhardt said.
“It’s hugely important because we want to implement this production method in our facility, with our own broodstock and hatchery producing juveniles and growing them through to 10 kilograms – keeping a close eye on water quality, temperature, [and more] throughout in a floating, closed system,” Sindilariu told SeafoodSource.
The floating facility will also mitigate the logistical issues, such as moving the fish to a grow-out facility, that tuna sometimes have at sales sizes ranging from 2 to 10 kilograms. At 10 kilograms, the facility will sell the fish, which will then go to sea cages for the grow-out phase.
In the meantime, the process of getting all the necessary permits in place for the first production system is well underway, Sindilariu said.
“In the second half of next year, we want to have our first fish from IEO swimming in [our] floating RAS – demonstrating what we want to do while we start breeding our first fish to become our own broodstock. We will then continue developing that side until we reach full production,” Sindilariu said.
After what Next Tuna hopes will be the successful operation of its first floating RAS, the company aims to add systems to its own tuna farming process – but also present the system to farmers of other marine species. Calling the floating RAS system an “innovation in itself,” Eckhardt told SeafoodSource the plan is to eventually market it separately with industry partners.
Next Tuna’s concept and strategy partly bets on the notion that the USD 40 billion (EUR 36.4 billion) global tuna market almost entirely relies on wild-catch fisheries and that further production growth will most likely come from aquaculture sources.
“If you want 8 billion people to be able to have tuna, you can’t just rely on commercial fishing,” Eckhardt said. “Also, tuna is one of the last remaining finfish seafood items that’s not been reproduced in aquaculture to a commercial scale. So, what we are doing makes sense in terms of supply and demand, and we believe sustainable aquafarming can open a few more markets and market segments to Atlantic bluefin.”
Eckhardt said five years ago, a land-based bluefin tuna aquaculture model might not have gained traction. But he said much of the skepticism around tuna farming in closed systems has been dissolved since Next Tuna began its work, in part because of technological advancements on production and feeding, and in part due to growing recognition that bluefin tuna need specifically designed systems and infrastructure.
“In terms of markets, we have a lot of interest – from supermarket chains and seafood distributors to grow-out farms,” Eckhardt said. “They’ve been saying, ‘If you can pull this off, we’re certainly going to buy it.’ On the investor side, it’s quite similar; We’re about to get a system in the water and evidence that the tuna can live there and will be happy in it. Again, that will be key.”
IEO’s ICRA facility in Cartagena has focused on bluefin tuna reproduction since 2015. Together with the nearby Mazarrón Aquaculture Plant, it was declared a “Singular Scientific-Technical Infrastructure for Bluefin Tuna Aquaculture” by the Spanish Ministry of Science and Innovation in December 2018 and given funding prioritization.
Murcia Oceanographic Center Director Fernando de la Gándara said he and his colleague Aurelio Ortega, the facility’s two lead researchers, have been working on closing the reproductive cycle of bluefin tuna for about 20 years.
IEO will continue working to improve Atlantic bluefin larval rearing and juvenile production techniques, especially those that increase growth and survival, taking into account all factors involved in the culture of the species, especially feeding and nutritional issues, Gándara said.
Having reached this advanced point in the research surrounding bluefin tuna reproduction, but with many obstacles still to overcome, the continued IEO work offers up a number of new opportunities, Gándara said.
“Up to now, we have had the Atlantic bluefin tuna fertilized eggs that we collect around the commercial cages of Ricardo Fuentes e Hijos, with whom we have maintained an excellent relationship, [but] having 100 percent IEO eggs gives us independence. In addition, the eggs obtained in the sea are mixed with the eggs of other species that, in their larval stages, grow faster than the Atlantic bluefin and prey on it, which is a serious problem,” Gándara said. “The eggs obtained at the ICRA are exclusively from Atlantic bluefin. It allows us to initiate genetic studies and extend and vary the spawning season by controlling the photoperiod and thermoperiod [of the fish].”
Photo courtesy of Next Tuna
