Blue whales and other baleen whales, which filter seawater through their mouths to feed on small marine life, once teemed in Earth’s oceans. In the 20th century, 1.5 million baleen whales were slaughtered in the southern hemisphere, including over 95% of the largest species — fin (Balaenoptera physalus) and blue whales (Balaenoptera musculus). Contrary to expectations, krill biomass on the former whaling grounds declined sharply (over 80%)...
