Tuna fish at Tokyo's Sea Life Park.

Tuna fish at Tokyo’s Sea Life Park. Image by Takashi Hososhima / CC BY-SA 2.0

The Tokyo aquarium Tokyo Sea Life Park has reported more Bluefin tuna, part of the ‘Voyagers of the Pacific’ exhibition, have died of unknown causes. Fish in the exhibition began dying earlier this month, and there are currently only six Bluefin tuna and five other fish still alive – there were 159 fish as of November last year. Officials at the aquarium have not found any abnormalities in the water quality. They continue to investigate possible causes for the deaths, and are trying to reduce stress on the fish. Read more: japantoday.com