Concerned about the fate of the imperiled North Atlantic right whale, a group of over two dozen scientists has written an open letter to President Obama asking him to stop the possible use of seismic surveys in the Atlantic.

The surveys, used to search for oil and gas deposits, use equipment towed behind boats to blast sounds into the oceans. The scientists are concerned that the noise pollution could threaten the endangered right whales, which are estimated to number only about 500. The mammals— decimated by whaling long ago— can grow to be almost 60 feet long.

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In the letter, the scientist say that they have “profound concern” about the vulnerability of the whales, and argue that despite conservation efforts over the past four decades, the North Atlantic right whale population may actually be shrinking. The researchers attribute this possible decline to the large amount of human activity on the east coast, and argue that noise pollution and hazards like fishing gear threaten the cetaceans. As whale health declines, so too does their ability to reproduce, the scientists report.

In March, the Interior Department said that new oil and gas leases wouldn’t be offered in the Atlantic, but the scientists— who hail from Cornell University, the New England Aquarium, the Wildlife Conservation Society, and Duke University— are worried that seismic surveys could still continue.

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“The North Atlantic right whale has managed to survive centuries of past whaling, and a host of recent threats such as ship strikes, fishing gear entanglement, and chronic noise from a range of human-generated sources,”  Dr. Howard Rosenbaum, Director of the Wildlife Conservation Society’s Ocean Giants Program, said in a statement. “Even with the proposal for oil and gas drilling off the table, potential impacts from seismic surveys are still of great concern, especially given the endangered status of these whales and the threats they already face.”