More than 150 fish died at an Japanese aquarium and only one survived . Workers at Tokyo Sea aquarium Park do not yet know what caused their deaths . Poisoning and factors that could have caused fish stress being explored . Tank contained 69 fish and 52 eastern little tuna , plus 58 oriental fish .
More than 150 fish died at an Japanese aquarium and only one survived . Workers at Tokyo Sea Life Park do not yet know what caused their deaths . Poisoning and factors that could have caused fish stress being explored . Tank contained 69 bluefin and 52 eastern little tuna , plus 38 oriental bonito .