In the fall of 1972, then-President Richard Nixon signed the Marine Mammal Protection Act, providing sweeping protections for whales, dolphins, seals and other species swimming in U.S. waters whose populations had dwindled due to commercial fishing and accidental killing.

More than 40 years later, a new report shows that the law has been effective: It not only prevented extinctions that seemed imminent, but also helped some species bounce back in strong numbers, researchers say.

(READ the story in LiveScience.com)