Offshore Seismic Surveys: Safety, Science, and Research
How do Seismic Surveys Impact Marine Life?
After examining decades of scientific research and real-world experience, federal regulators determined that seismic surveys in the Atlantic OCS will have no measurable impact on fish or marine mammal populations.
- In the words of the federal Bureau of Ocean Energy Management (BOEM), “there has been no documented scientific evidence of noise from air guns used in geological and geophysical (G&G) seismic activities adversely affecting marine animal populations or coastal communities.”
- According to BOEM, seismic surveys in the Atlantic OCS “should not cause any deaths or injuries to the hearing of marine mammal[s] or sea turtles.”
- Dr. William Brown, chief environmental officer for BOEM, told National Geographic that claims to the contrary are “wildly exaggerated and not supported by the evidence.”
- While fish and some whales may swim away from an area and return after the survey vessel has passed, bottlenose dolphins are known to swim toward survey vessels to ride their bow waves.
Despite the already negligible risks, the industry follows standard operating procedures known as “mitigation measures” to provide even more protection for marine life.
- Trained protected species observers (PSOs) are onboard to watch for animals. Operations stop if certain marine animals enter an “exclusion zone” established around the operation and are not restarted until the zone is all-clear for at least 30 minutes.
- When starting a seismic survey, operators use a ramp-up procedure that gradually increases the sound level being produced, allowing animals to leave the area if the sound level becomes uncomfortable.
What is the Current State of Science and Research?
The best science and research indicates that seismic surveys have little-to-no impact on marine wildlife populations.
- Based on both available scientific knowledge and operational experience, there is no evidence to suggest that the sound produced during an oil and gas industry seismic survey has resulted in any physical or auditory injury to a marine mammal.
- Seismic surveys are predominantly low frequency. Not all marine life hears the same frequencies equally well. Just as humans, bats and dogs hear differently, some marine animals hear better at higher frequencies while others hear better at lower frequencies.
- The best available scientific information also indicates that any sound related injury to dolphins occurs at levels higher than the sound generated by a seismic survey.
- Animal strandings can occur for a number of reasons, e.g., sickness, disorientation, natural mortality, extreme weather conditions or injury, but no correlation has been found with seismic surveys.
The industry remains committed to improving the scientific understanding of the impacts of our operations on marine life.
- To provide the utmost safety precautions, seismic surveys in the U.S. Outer Continental Shelf are only conducted with measures in place to protect animals from high sound exposure levels.
- Industry continually monitors the effectiveness of its mitigation strategies and funds research to better understand interactions between offshore operations and marine life, including fish.
Developed in conjunction with the International Association of Geophysical Contractors (IAGC) and the National Ocean Industries Association (NOIA).