Right now, whale are endangered and near extinction because people hunt them and it is started from 200 years ago. People were hunted whale in order to take their meat, oil, or whale bones. In the '70s Save Whale Movement made a campaign to stop commercial of using whale to attract people and in early '80s this campaign had a successful result. Government banned to air a commercial whaling. Many people think that whale should be saved because of its charismatic and beautiful but actually whale is an ecosystem engineer which maintain stability and health of the ocean also provide services to human communities.
There are two main things of whales which help ecosystem, the poop and the corpse. Whale pump (poop) are contains of much essential nutrients to entire ecosystem. Whale carcasses provide a food to other fishes and help to delay global warming. When the corpse washed up in beaches it's provide feast to many species in land. People need to stop whaling and revise their thinking to save the whale not only for whale sake but also for human itself.
Link : ted.com/talks/asha_de_vos_why_you_should_care_about_whale_poo#t-90122