In 1972, a U.S. Senate committee reported, "Many of the great whales which once populated the oceans have now dwindled to the edge of extinction," due to commercial hunting. The committee also worried about how tuna fishing was accidentally killing thousands of dolphins, trapped in fishing gear. And they considered reports about seal hunting and the decline of other mammals, including sea otters and walruses.
In October of that year, Congress passed the Marine Mammal Protection Act.
Four decades later, new research shows that the law is working.
Not only has the act "successfully prevented the extirpation of any marine mammal population in the United States in the forty years since it was enacted," write University of Vermont conservation biologist Joe Roman and his colleagues in a new report, but also, "the current status of many marine mammal populations is considerably better than in 1972."
Their study, published online on March 22, in the Annals of the New York Academy of Sciences, shows that population trends for most stocks of these animals remain unknown, but of those stocks that are known, many are increasing.
"At a very fundamental level, the MMPA has accomplished what its framers set out to do," says co-author Andrew Read, professor of marine biology at Duke University, "to protect individual marine mammals from harm as a result of human activities."
Some marine mammals, like endangered right whales, continue to be in deep trouble, but other populations "particularly seals and sea lions, have recovered to or near their carrying capacity," the scientists write.
"We have seen remarkable recoveries of some populations of marine mammals, such as gray seals in New England and sea lions and elephant seals along the Pacific coast," says Read.
"U.S. waters are pretty compromised with lots of ship traffic and ship strikes, big fisheries, pollution, boat noise, " Joe Roman says. "And
|Contact: Joshua Brown|
University of Vermont