At Tokyo Sea Life Park, the number of Pacific Bluefin Tuna and other fish in the "Voyagers of the Sea: Tuna" tank is decreasing. The tank contains Pacific Bluefin Tuna, Kawakawa, Striped Bonito, but since early December 2014, Kawakawa and Striped Bonito have been dying continuously, and since late December, Pacific Bluefin Tuna have also been dying in succession.


Pacific Bluefin Tuna (photographed on December 1, 2014)
Normally, some fish die shortly after being introduced into a tank, but this situation is unprecedented. We have been administering medication based on consultations with experts and have been working to eliminate as many potential stressors as possible (such as changes in brightness, vibrations and noises from construction or work), but since the deaths continue, we are informing you without waiting for the results of the pathological diagnosis.

We are currently working to determine the cause and are considering countermeasures. We sincerely apologize for any inconvenience this may cause and appreciate your understanding and cooperation.

◎ About the "Voyagers of the Sea: Tuna" tank
Diameter approximately 30 meters, maximum depth 7 meters, water volume approximately 2,200 tons

◎Number of individuals

Species name	November 1, 2014	January 14, 2015
Pacific Bluefin Tuna	69	17
Kawakawa	52	4
Striped Bonito	38	9

◎Reference

● Pacific Bluefin Tuna (Mackerel family) IUCN Red List: VU (Endangered Class II)
Scientific name: Thunnus orientalis
English name: Bluefin tuna
Body length: about 3m
Weight: about 300kg
Distribution: Widely distributed along the coast of Japan and the North Pacific Ocean
Ecology: In the wild, some individuals can exceed 3 m in length and weigh over 300 kg. The maximum swimming speed is said to reach 80 km/h. The distribution name is red tuna. It is traded at a high price as sushi ingredients, sashimi toro, and lean meat. Currently, there is a global concern about the decline of Pacific Bluefin Tuna resources.

● Kawakawa (Perciformes)
Scientific name: Euthynnus affinis
English name: Kawakawa
Body length: about 1m
Weight: Approx. 10kg
Distribution: Widely distributed in temperate to tropical zones in the Indian and Pacific Oceans
Ecology: It is a member of the bonito family, has a strong coastal area, and does not form large schools as large as bonito, but migrates in small groups. It is caught with fixed nets and pulllines. Delicious as an edible fish.

● Striped Bonito (Mackerel family)
Scientific name: Sarda orientalis
English name: Striped bonito
Body length: about 50 to 60 cm
Weight: about 5-8kg
Distribution: Widely distributed from temperate to tropical zones around the world
Ecology: It is a member of the bonito family and can form large schools along the coast. They also form schools of konei with bonito and tuna. It is caught in fixed nets and pulllines, and is also delicious as food.

(January 14, 2015)