Currently, Pacific bluefin tuna (PBFT) farming production relies on catching wild juvenile tuna and raising them to maturity before distributing the fish to markets, but this practice is unsustainable, as it increases fishing pressure on the wild population, according to an announcement from the Foundation for Food & Agriculture Research (FFAR).

FFAR announced March 11 that it has awarded a $945,000 grant to Ichthus Unlimited LLC to cultivate PBFT eggs as part of a sustainable model for tuna farm production.

“Today, 98% of tuna ranching relies on wild-captured fish for the stocking of net pens. This adds to the already massive fishing pressure on wild bluefin tuna populations,” Alejandro Buentello, president of Ichthus Unlimited, said. “Hatchery-reared tuna will not only make it possible to stock cages without fishing, but it can also be used as a stock enhancement strategy to empower wild tuna populations to rebound more rapidly. It is a proactive rather than reactive strategy.”

With the grant, Ichthus will establish a hatchery in the San Diego Bay area of California to cultivate PBFT eggs and grow them to juvenile fish, which can then be distributed to tuna farms to mature, FFAR said. Acquiring tuna from the hatchery rather than from the wild population should reduce rates of overfishing and help stabilize the wild population. At only 3% of its original population, PBFT are on the verge of being placed on the Endangered Species List.

“Bluefin tuna aquaculture represents a major new high-value market for U.S. farmers, but there is much science to be done to produce the fish entirely under farmed conditions,” FFAR executive director Sally Rockey said. “This research has the potential to not only stabilize the wild population but also create economic opportunities in farming the delicacy.”

As the “Holy Grail” of aquaculture, bluefin tuna can sell for tens of thousands and occasionally millions of dollars per fish, FFAR said, estimating that bluefin species products generate approximately $2.0-2.5 billion in value worldwide each year. Increases in tuna production would also create jobs and economic gains, particularly for coastal communities in California and the Gulf of Mexico.

Despite the popularity of PBFT, few indoor facilities in the world have the expertise needed to raise PBFT from eggs, FFAR said. The team at Ichthus will collaborate with these indoor hatching facilities and leverage their combined knowledge to successfully implement this practice.

This will be the first tuna hatchery in North America and the third bluefin hatchery in the world.

FFAR has convened world-renowned experts to develop a practical approach that enhances PBFT egg production and, subsequently, produces more tuna. The private/public partnership includes Ichthus Unlimited, the Illinois Soybean Assn. (ISA), Texas A&M University and the Spanish Institute of Oceanography.

ISA director of strategic market development Mark Albertson noted that the FFAR grant will augment ongoing support from ISA's checkoff program that has been developing sustainable feed research targeted toward very early growth stages at a tuna hatchery.

"High global demand increases tuna value and induces overfishing of wild stocks," Buentello said. "The tuna ranching industry is constrained by a stringent quota system that limits the amount of wild tuna they can catch to stock in oceanic cages. With ISA support, we successfully developed soy-based feed that can be commercially manufactured.

"Now, we have the knowledge and ability to take the next step," he added. "Closed-cycle aquaculture, combined with sustainable diets, offer the best opportunity to prevent wild tuna stocks depletion while meeting global demand."

For the past three years, Buentello has led ISA-funded research to develop sustainable soy-based diets for tuna. He explained that feeding large quantities of wild-caught baitfish like sardines is environmentally unsustainable, while the nutritionally dense soy-based diet improves feed conversion rates, reduces waste and improves meat quality.

"Soy protein is a complete protein that replaces fish meal in diets for many aquatic species and has become the top ingredient in aquaculture feed," Albertson said. "ISA filled a research gap in alternative protein research for tuna that existed because of the species' complexity. We've laid the foundation to use soy-based feed from early development through maturity."

The ISA-funded research tested various soy-based diets for larval Atlantic bluefin tuna in Spain, where survival rates improved at least 30% compared to other diets. Juvenile yellowfin tuna in Panama land-based facilities also tested formulated feed options. Building on these experiences, trials with mature, ranched PBFT in ocean net pens in Mexico confirmed the viability of the soy-based diet, an announcement from ISA said.

The formulated diet decreases the feed conversion ratio from 28:1 with wild-caught sardines to 4:1 and reduces the amount of fish meal and fish oil in feed by tenfold, ISA said.