A series of seismic surveys for oil and gas planned for the mid- and southeastern Atlantic coastal areas of the United States pose a substantial threat to one of the world’s rarest whales, according to a group of renowned marine mammal scientists urging a halt to the surveys.

In an open letter sent to President Obama, the 27 leading right whale expert said that the surveys planned in the waters between Delaware and Florida would significantly impact the acoustically sensitive North Atlantic right whale, an endangered species numbering no more than 500 animals, and “would jeopardize its survival.”

The statement says that the surveys would introduce a significant amount of noise pollution into the area of ocean most critical for the survival of the North Atlantic right whale (Eubalaena glacialis), an animal that gives birth and nurses in the relatively warm coastal waters from North Carolina to Florida. The cacophony produced by the airguns in the survey is likely to disrupt the whales’ behaviour, with the resulting stress affecting the health of the animals.

“The airguns used for seismic oil and gas surveys produce intense explosions every 9 to 11 seconds for many weeks or months at a time. All of this is undetectable to someone at the surface, but the underwater impact and disturbance from these activities can be devastating to ocean life, especially for species such as the North Atlantic right whale,” said Dr. Christopher Clark, Senior Scientist for the Cornell Lab of Ornithology Bioacoustics Research Program.

North Atlantic Right Whale
North Atlantic Right Whales

The proposed seismic surveys will use arrays of airguns towed behind ships as they explore for oil and gas deposits beneath the ocean floor. The blasts of sound produced by the guns penetrates the seafloor, and the returning echo reveals the presence of potential fossil fuel deposits. These extremely intense explosions are damaging to marine life, and whales are known to avoid or abandon survey areas. Companies have applied to survey as much as 90,000 miles of trackline off the East Coast, running back and forth over the same area during the first year alone.

“The North Atlantic right whale is protected by US, Canadian, and international laws, and over the last three decades, we’ve seen slow growth in the population.” said Dr. Scott Kraus, Vice President of Research for the New England Aquarium and head of a long-running science program on the species. “However, this growth has been lower than expected, and the latest data indicate a recent population decline. Threats such as fishing gear entanglement, existing noise pollution and other factors continue to impede the right whale’s recovery. Seismic surveys could interfere with communication, elevate chronic stress, and will disproportionally affect the most vulnerable members of the population, mothers and calves. Seismic exploration in the Atlantic will make this whale’s situation even worse.”

Growing to 15 m long, the North Atlantic right whale was one of the first targets of the world’s commercial whaling industry – the “right whale to hunt” – and was rapidly wiped out from the animal’s coastal habitats in the Atlantic before whalers moved onto other species. It’s thought they live to 50 years, but there has been little research to confirm this. Females give birth to their first calf at around 10 years old in shallow, coastal waters. According to NOAA Fisheries, in 2011 (the most recent year for which there are figures) there were an estimated 465 North Atlantic right whales.

The species is designated as “Critically Endangered” on the IUCN’s Red List of Threatened Species, and is protected in U.S. waters by the Endangered Species Act and the Marine Mammal Protection Act.

Noise from a single seismic airgun survey can blanket an area of over 300,000 km2, raising background noise levels 100-fold (20 dB), continuously for weeks or months. Additionally seismic airguns can be heard 4,000 km away from the survey vessels

Further Reading

read the letter here
A Review of the Impacts of Seismic Airgun Surveys on Marine Life, Lindy Weilgart, Dalhousie University

Photo by Wildlife Trust, NOAA Permit #594-1759, (CC BY-NC-SA 2.0)


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