The ocean is filled with a wide variety of natural and man-made sounds. Some are generated by the energy industry in the search for oil and natural gas. Safeguarding amazing ocean dwellers depends both upon years of academic research and on careful operations.

Below we’ve gathered commonly asked questions and answers on the energy industry’s use of sound science to protect marine mammals.


Why use sound to explore for oil and gas?Linda Zimmerman, ExxonMobil
Dr. Linda Zimmerman
Geophysical Advisor and Physicist, ExxonMobil

“Sound is integral to the search for oil and gas. The energy industry uses seismic technology to help determine where to drill. Sound wave reflections are used to map geologic formations below the ocean floor. These 3-D images identify potentially oil- and gas-rich sedimentary formations. Such detailed imaging reduces the number of wells needed to explore for and produce oil and gas resources.”


Are marine mammals hurt by seismic waves?Harry DeFerrari, Department of Ocean Sciences, University of Miami
Professor Harry DeFerrari
Department of Ocean Sciences, University of Miami

“Peer-reviewed scientific studies conducted over the past four decades show no evidence that the sounds produced for oil and gas exploration have hurt marine mammals. Further, there is absolutely no evidence that seismic surveys have had any role in diminishing populations of marine mammals. The scientific issue of concern today is how sounds might affect behavior or stress the animals. This presents a most difficult observational/experimental challenge. Until these issues can be resolved, great care is being taken to keep the duration of seismic surveys as short as possible and always carefully timed to avoid migration or other critical mammal activity.”


How are marine mammals kept safe during offshore seismic operations?Gary Isaksen, Manager of Sound and Marine Life Programs, ExxonMobil
Dr. Gary Isaksen
Manager of Sound and Marine Life Programs, ExxonMobil

To mitigate against adverse impacts to marine mammals, environmental information is evaluated ahead of seismic acquisition activities to identify sensitive times and regions, such as breeding times and feeding grounds. We also use computer models to understand what levels of sound, and the frequencies, that may cause whales and dolphins to react. Surveys are then designed to address potential impacts. Marine seismic exploration is carefully regulated by the governments and managed by the operator to safeguard marine animals.


What is a marine mammal observer?MMO
Stephanie Milne
Senior Marine Environmental Program Manager at RPS Group
Former Protected Species Observer and Passive Acoustic Monitoring Operator

“Marine Mammal Observers or Protected Species Observers are trained and certified professionals who are deployed offshore during activities where sound is produced that has the potential to impact marine mammals or other species of interest, such as during seismic acquisition. The Marine Mammal Observers’ duties include conducting visual and/or acoustic monitoring for marine species and implementing appropriate mitigation measures such as delaying or shutting down operations if specific species are detected inside an exclusion zone around the active sound source. They are an important part of the team, advising the seismic crew on how to conduct operations in compliance with environmental regulations. They also have the responsibility of collecting standardized, scientific data to enable them to prepare reports for submission to clients and regulatory agencies.”


What other mitigation measures are used?Robert Gisiner, Director, International Association of Geophysical Contractors
Dr. Robert Gisiner
Marine Biologist
Director, Marine Environmental Science and Biology
International Association of Geophysical Contractors

“When seismic operations start or are interrupted for more than a short time, a gradual increase in sound from the seismic sound sources is used to allow marine mammals time to move before the source reaches normal operating levels. This gradual increase in source levels allows sufficient time for them to move to their preferred separation distance.”


How does the oil and gas industry support ocean conservation?Roger Gentr, US National Ocean and Atmospheric Administration (NOAA)
Dr. Roger Gentry
Former Head, Acoustic Program, U.S. National Oceanic and Atmospheric Administration (NOAA)

“Twenty years ago the public began asking whether sound from human activity at sea affects the conservation of marine life. No marine-based industry has done more to answer that question than the oil and gas industry. To date it has provided $55 million in research funds to understand how sound affects marine mammals, and has conducted marine mammal observations at sea in many areas where few data previously existed. These combined efforts have greatly increased our understanding of noise and ocean conservation.”


Can whales control their own hearing?
London NSF Paul
Professor Paul Nachtigall
Hawaii Institute of Marine Biology
University of Hawaii

“Yes, toothed whales (odontocetes) are able to conditionally control their hearing sensitivity, especially when elevated sound levels are preceded by a faint sound. This faint sound could be described as an alert to a subsequent louder sound. This makes sense from an evolutionary point of view. Sperm whales are known to generate some of the loudest sounds in nature when hunting for squid. Echolocation clicks that have been measured over 235 dB (re 1 uPa, peak to peak) are produced in the whale’s head. The dampened hearing sensation change ranges from 15 to 20 dB and is considered to be a classically conditioned response. Research to date by my colleagues and me shows remarkable similarities in self-regulated hearing among for the four odontocete species studied: false killer whales, beluga whales, bottlenose dolphins and harbor porpoises.

The extensive research done with several species of toothed whales was, almost in its entirety, funded by ExxonMobil’s Ocean Science Program. ExxonMobil’s leadership in this area has greatly expanded our knowledge of marine mammal hearing.”


Interested in learning more?
The Sound and Marine Life Joint Industry Program has funded a number of academic research studies. Results from this work enable the industry to continue to improve its environmentally responsible operations. Research findings are available at


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