1,200 fish found dead in Tokyo aquarium

A lack of oxygen has led to the deaths of more than 1,200 fish at an aquarium in Japan.

A major Tokyo aquarium has said that more than 1,200 of its fish were found dead - likely due to lack of oxygen.

Sunshine Aquarium announced on Thursday that a total of 1,235 fish, which represents about 94 per cent of the fish in its largest tank, have died.

The incident happened after the operator stopped a bubble-producing cleaning device for the tank on Tuesday to improve the effect of chemicals added to the water to treat some unhealthy fish.

The move was thought to have led to a decline in oxygen concentration, though the operator kept providing oxygen to the tank through another device, local media reported.

The aquarium resumed operations on Thursday after a one-day suspension.