Tazi Phillips, Global Animal

Marine conservation organization The Black Fish successfully released over a thousand bluefin tuna back into the Adriatic Sea from cages at a fish farm near the island of Ugljan, Croatia. The operation marks the start of a new international campaign to highlight the lucrative trade of bluefin tuna, a species heavily impacted by illegal overfishing and labeled as a species of concern by the NOAA and listed on the IUCN’s Red List. 

The Kali Tuna cages off the coast of Croatia. Photo credit: Umami

Kali Tuna, a subsidy of the US fish farming company Umami Sustainable Seafood based in San Diego, California, is “considered one of the most respected and trusted suppliers of premium sushi grade tuna in Japan.” Driven largely by the growing popularity of sushi, the company helps to produce a fish supply that they market to the Japanese, who traditionally consume 80% of the bluefin tuna around the world. 

What Is Fish Farming?

The word “farming” in the case of bluefin tuna is used inaccurately. Compared to other species of farmed fish such as salmon, it is nearly impossible for bluefin tuna to naturally reproduce in captivity. Instead, wild bluefin are caught in large nets and transferred to circular ocean cages where they are fed until they grow up to 10 times their size in the wild. They remain at the farms for up to 42 weeks, at which point they are “harvested,” packed and shipped to wherever the demand is. 

While producing larger fish could potentially slow down demand, farms like those in Croatia are still able to catch smaller tuna before they are able to spawn, effectively depleting the reproductively viable wild tuna populations. 


Umami prides itself on their adherement to a sustainable form of fishing, stating, “We strictly adhere to catch levels scientifically required to permit the replenishment of bluefin and other overfished species in specific regions. We have fought for lower quotas and stricter controls over the last several years, and our stance remains that all fishing should be subject to quota, based on a scientific assessment of maximum annual yield.” The problem is that Umami does not necessarily adhere to quotas and limitations, something that the juvenile populations found at their Kali fish farm prove.

Tuna are transferred from a fishing net to holding cages at a tuna farm. Photo credit: Marco Carè/Marine Photobank.

What Umami does not disclose is the prime locations for their operations, especially Kali Tuna in Croatia. The Adriatic Sea is one of the best locations for bluefin tuna, the shallow sea allowing for warmer waters throughout the year that produce a large juvenile population. In 2010, the International Commission for the Conservation of Atlantic Tunas (ICCAT) implemented a new rule for fishing in the greater Mediterranean Sea that prohibits catching bluefin tuna under 30kg. The regulation gives juvenile fish the opportunity to spawn for at least one cycle before being caught. However, arguing the area is a traditional fishing ground, Croatia became an exemption to the rule as long as they did not use the undersized fish for farming.

But Weitse van der Werf, co-founder and international director of The Black Fish, said many of the fish released last week ranged in size, indicating that juveniles were caught in the wild and transferred to the farm cages along with older fish. Van der Werf states, “This exemption is a form of legalized poaching. By continuing to catch juveniles, these endangered fish simply don’t stand a chance of reproducing. We are calling on ICCAT delegates to end Croatia’s special treatment and work towards adequate measures to combat the bluefin tuna trade and ensure one of the largest and fastest predators of the ocean stands a chance of survival.” 

Umami CEO Oli Steindorsson believes the company’s operations are helping to sustain the species. In a 2011 interview with SmartPlanet, Steindorsson says, “We’re protecting them from predators. Fish spend 80 percent of their life searching for or eating feed. We’re providing food for them, keeping them in a clean environment. For every kilo we feed the fish, they would need three to five kilos in the wild because they are moving so much more. Mother Nature will not give them fish to eat every day.” What he fails to mention that these fish are only being fed in order to kill them once they have reached a marketable size. And the only predators bluefin tuna need protection from are humans. The species has been around for more than 400 million years, making them older than the Himalayas and quite able to survive on their own.  

In a Washington Post article, Marc Kaufman writes, “Over the past 100 years, some two-thirds of the large predator fish in the ocean have been caught and consumed by humans, and in the decades ahead the rest are likely to perish, too.” Small fish are flourishing in the absence of tuna and other larger fish that traditionally feed on them, creating an ecological imbalance that experts say will permanently change the oceans. The problem is not with a lack of food for bluefin tuna. The problem is us and the unsustainable demand for a product that is quickly disappearing from our oceans.

More On Bluefin Tuna: 

Deadliest Catch For Bluefin Tuna

Fukushima Radiation Found In Bluefin Tuna

Sea Shepherd Entering Warzone To Protect Bluefin