If you are going to stop whaling because they are mammals then I suggest you stop eating beef goat sheep and pig all are mammals.
As to the whale for scientific reasons as proclaimed by the Japanese its not true obviously as the whale meat is sold for food
Grenade going off in a whale is probably less traumatic in magnitude than stun gunning 200 cows which would equate in protein/fat weight to one humpbback.
Its so easy for some on here to be high an mighty and tell the Japanese to stop whaling , I dont see them telling Oz to stop sending coal to China which ends up polluting their air.