Bill Nelson, D-Florida, is one of 18 senators asking President Barack Obama to deny permits for seismic gas testing off the Atlantic coast.
Seismic testing uses sonic booms to search for natural gas reserves, and scientists are worried the testing will hurt whales.
The practice is outlawed along the Atlantic seaboard, but Obama is under increasing pressure to allow gas companies to explore.
Environmentalists fear the testing could confuse the endangered North Atlantic right whale. National Oceanic and Atmospheric Administration scientist Greg Silber said the whales use sonar communication to navigate.
“The communications systems for these animals is vital to hold a calf nearby, or to locate mates, or to communicate with other individuals in a loose herd,” Silber said.
But seismic testing could disrupt their mating pattern in the Northeast and birthing off the coast of Florida, he said.
Until the testing is proven safe, Nelson is recommending the president reject all permits, calling the sonic blasting unnecessary.