U.S. Rep. Neil Abercrombie yesterday commemorated Earth Day by introducing legislation to create a national research program focusing on the effects of human-related activities — such as the use of sonar — on marine mammals, his office said.

Abercrombie's legislation would establish a comprehensive research program into the effects of human-related activity, and particularly the use of sonar by the U.S. Navy.

Sonar is the essential tool of anti-submarine warfare and is also used for undersea mapping and scientific exploration. But its powerful sound beams can damage the sensitive hearing or marine mammals — primarily whales and dolphins— and may have even caused some deaths.

"We need to end the fighting and resolve these issues, but we can't really do that until we're sure we all know what we're talking about," Abercrombie said in a statement. "We have to fully understand the effects of human activities, including underwater sound, on marine mammals and determine how to mitigate any harmful impact. That requires expanded and focused research."

Abercrombie's bill would authorize $25 million in annual funding to coordinate and strengthen scientific research into natural and human-related factors affecting the health of marine mammals and their habitats. The program would be administered by the Marine Mammal Commission, an independent federal agency.