The Dream Of Tuna In An Aquarium

In the around 250 aquariums and marine centers in all different parts of the globe, tuna is a rare sight. Only a handful of aquariums around the world choose to keep tuna as part of their ocean displays, and this can leave many unaware of the massive size a tuna can grow to and the wide range of species the name can cover. Why is one of the world’s most important oceanic species rarely on show in these marine centers that are such popular destinations for both tourists and locals in nearly every country?

One of the exclusive facilities that does feature tuna is the Aquamarine Fukushima in Japan, which now has around 100 specimen of skipjack, 10 yellowfin and a few bluefin, as part of its exhibitions. An executive from the center told Atuna why they were so keen to bring tuna into the public eye.

“Keeping tuna in aquarium tanks had been our dream,” the site’s Executive Director, Yoshitaka Abe says, but stresses it does not come without its challenges. Since part of the Fukushima exhibit is a greenhouse structure, and therefore very bright, the main tank of the aquarium has too much light for the bluefin, as they are deep water fish in the wild, Abe states. Skipjack and yellowfin are a lot easier to keep in a tank than bluefin, Abe explains.

However, due to its speedy movements and sometimes giant size, many aquariums shy away from keeping tunas. Abe argues that they are the most difficult fish to keep in an aquarium tank because of problems in all stages of getting the animals into the basins, such as collection and transportation, as well as keeping them alive. All of these obstacles make them an unpopular species to keep in captivity.

Due to the big size and fast speed of tunas, they require large tanks, something Abe claims only a few aquariums around the world are equipped with. He emphasizes the speedy behavior of tunas, saying that they can swim very fast without a break, and that it is very difficult to create the same stimuli for them in an aquarium as they would experience in the wild.

In Japan, a total of four aquariums keep tunas; Tokyo Sealife Park, Kaiyukann Osaka Aquarium, Churaumi Aquarium Okinawa and Aquamarine Fukushima. In the US, the main aquarium exhibiting these fish is the Monterey Bay Aquarium in California.

Tokyo Sealife Park is one marine facility which has experienced the devastation tuna in captivity can cause. In 2015, the aquarium saw all but one of its 150 tunas be wiped out of what is believed to have been a mysterious disease. A high number of deaths and shorter lifespans are among the reasons why some oppose keeping tuna and other marine species in captivity.

One group which has spoken out against the practice of keeping any living specimen in captivity is animal rights organization People for the Ethical Treatment of Animals (PETA). It states that fish are denied their natural environment when being kept in a tank, and that it can cause them both physical and psychological harm. The organization encourages people not to visit aquariums and marine centers due to these reasons.

There have been incidents that show PETA’s concerns can be justified, as tunas being held captive have died as a consequence of being handled by humans. Tokyo Sealife Park encountered troubles when transferring the fish, with specimen dying the same day they were introduced to the park. They were just one year old and the cause was not revealed, but many of the tunas were found with broken spines which experts said could have been caused by the fish bumping into the glass due to “stress and hysteria”.

Despite the many difficulties of possessing tuna in captivity, Abe explains that the public loves to observe the tunas when they have the chance, with the Director describing them as “jet fighters”. Many are unaware of just how big tunas can be, and also the differences between the various types. Even though there is little doubt that the majestic animals thrive most in the ocean, aquariums give individuals the opportunity to learn about the fantastic creatures and the importance of conserving them, while staying dry on land.