Preserving just 4 percent of the ocean could protect crucial habitat for the vast majority of marine mammal species, from sea otters to blue whales, according to researchers at Stanford University and the National Autonomous University of Mexico.
Their findings were published in the Aug. 16 edition of the Proceedings of the National Academy of Sciences.
Of the 129 species of marine mammals on Earth, including seals, dolphins and polar bears, approximately one-quarter are facing extinction, the study said.