or alternatively we could just leave them the fuck alone
Naw, that will never happen...check the Japanese and their slaughter of dolphins, and in Asian countries the slaughter of sharks for shark fin soup (PETA only cries when cutesy animals are slaughtered)
Understanding marine mammals is key to understanding ourselves and our role in this world---it makes it more humbling and makes one appreciate the flora and fauna of this world.
Besides, the marine world is still alien to us, new creatures being found...creatures that possibly marine mammals such as the tooth and baleen whales have seen before. Communication with them can actually open up this world to us. Also, look at giant squid, in order to understand them, scientists look to sperm whales, which feed on giant squid.
Just leaving things alone, ain't the answer. Using respect and appreciation is the key.