Tag Archives: marine mammals

New Course Explores Science of Noise Impacting Marine Mammals

The Beluga whale is one of over 120 species of marine mammals impacted by ocean noise.
The Beluga whale is one of over 120 species of marine mammals impacted by ocean noise.

Applied Technology Institute Introduces New Course:

Underwater Acoustics for Biologists and Conservation Managers

New course explores the science of noise that impacts marine mammals and other ocean life

(ANNAPOLIS. Md, May 17, 2010) Technical professional development training company, Applied Technology Institute (ATI), is introducing a new course, Underwater Acoustics for Biologists and Conservation Managers. The three-day course is designed for biologists and conservation managers who wish to enhance their understanding of the underlying principles behind underwater and engineering acoustics. Understanding this science is critical to the success of marine research facilities that are responsible for evaluating the impact of anthropogenic noise on marine life.

Target audiences will include marine research facilities like the Office of Naval Research (ONR) and the National Oceanic and Atmospheric Administration (NOAA). Currently the NOAA is overseeing the BP oil spill clean up that occurred in the Gulf of Mexico last week. The NOAA umbrella organization includes divisions responsible not only for environmental clean up emergencies, but also for assessing biological harm to marine life through the NOAA Fisheries Services division.

Take this course to make better assessments of the impact of sound on marine life

Specific course outline points include learning about key characteristics of man-made sound sources, evaluating sound fields from impulsive coherent and continuous sources, discussing how system characteristics are measured and calibrated, as well as what animal characteristics are important for assessing both impact and requirements for monitoring and mitigation. By the conclusion of the course attendees will have obtained the knowledge to perform basic assessments of the impact of anthropogenic sources on marine life in specific ocean environments, and to understand the uncertainties in their assessments.

Together, ATI Instructors, Dr. William T. Ellison and Dr. Orest Diachok, bring more than eighty years of expertise in marine acoustics and biology to share with attendees.

The full course outline can be viewed on ATI’s website at:

Course Outline: Underwater Acoustics Biologists Conservation Managers

Sample materials are available on ATI’s website for prospective attendees interested in seeing the value of the course before registering. Click on the following:

Sample Materials: Underwater Acoustics Biologists Conservation Managers

Date, Time and Location:

The first class will be offered from 8:30 am to 4:30 pm on June 15-17, 2010 in Silver Spring, MD (just outside of Washington, DC). Space is limited. Call today to reserve a seat.


The ATI Courses Team

P.S. For registration: Call today at 410-956-8805 or 888-501-2100 or go online now at ATIcourses.com

About Us

The Applied Technology Institute (ATI) specializes in professional development seminars in the technical areas of Space, Communications, Defense, Sonar, Radar, and Signal Processing. For over twenty-five years, ATI has presented leading-edge technical training to defense and NASA facilities, as well as DoD and aerospace contractors. ATI courses provide a clear understanding of the fundamental principles and a working knowledge of current technology and applications. ATI has the unique capability to schedule and deliver courses in a matter of weeks. They offer customized on-site training at your facility anywhere in the United States, as well as internationally and over 100 public courses annually in dozens of locations. World-class design experts lead courses. To register or for an on-site quote, call (888) 501-2100, or visit them on the web at www.ATIcourses.com

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Sound Levels and Mammal Mitigation

The effect of mid-frequency sonar on marine mammals is a controversial topic. This was originally posted on a Navy web site.

Comparing Mid-Frequency Active Sonar to a Saturn V Rocket

For several reasons, it is inaccurate and misleading to claim that the sound of mid-frequency active sonar in water is equivalent to a Saturn V rocket. Sound levels in water and sound levels in air are expressed very differently*, and therefore comparing sound levels in water and air must be done carefully.
As an example of the difference in the way sound levels are received in air versus water, note that a sound level of 120 dB sound pressure level in air (similar to a rock music amplifier 4-6 feet from the listener) can cause hearing damage or distress to humans and animals, while human divers and animals receiving 120 dB sound pressure level underwater experience no such issues.

1. Saturn V Rocket is 10x Louder: At 1000 yards (914 m) from a Navy ship, the receive level for mid-frequency active sonar is approximately 175 dB in water. At the same distance in water, a Saturn V rocket would register 197 dB. This 22 dB difference means that the Saturn V rocket would have approximately ten times greater intensity than mid-frequency active sonar at the same distance. Temporary threshold shift (TTS), which is the National Marine Fisheries Service’s baseline for non-permanent effects on marine mammals, is 195 dB, so the Saturn V rocket would have the potential to cause TTS to marine mammals at 1000 yards, whereas mid-frequency active sonar at the same distance would not.

2. Saturn V Sound is Continuous, Mid-Frequency Active Sonar Sound is Intermittent: Rocket engine noise is a continuous sound source, lasting for many minutes at a time. By comparison, sonar pings are intermittent, with each ping lasting one second or less and being repeated about every 30 seconds. Over the course of one minute, ship and animal movement at sea would make it very unlikely that a marine mammal would be exposed to even two sonar pings. By comparison, marine mammals would be far more likely to be exposed to the continuous “roar” of rocket engine sound during a similar timeframe.

3. Saturn V Frequencies Would Potentially Affect More Species: Rocket engine sound is a broadband sound, spanning as many as five octave frequencies. Sonar signals are limited to a narrow band, typically 1/3 octave frequencies or less. The greater number of frequencies from the broadband rocket sound would make it likely that more types of species would be affected by the rocket sound than by the narrow band sound of mid-frequency active sonar.

*All sound levels in water are referenced to 1 microPascal (μPa). All sound levels in air are referenced to 20 microPascal (μPa), often expressed as sound pressure level (SPL). Sound waves with the same intensities in water and air have relative intensities that differ by 61.5 decibels (dB). Therefore, 61.5 dB must be added to relative intensities in air to obtain the relative intensities of sound waves in water.

Whales and the Navy

Whales and the Navy
By Susan Chambers, Staff Writer
Tuesday, February 10, 2009 |

The U.S. Navy, pressured by coastal residents has extended a comment period on its plans to double its area for training off the coasts of Northern California, Oregon and Washington.

News of the Navy’s plans spread through e-mails and on blogs on the Internet two weeks ago as notices about public meetings were sent out. But many folks were outraged, contending there was insufficient public notice and too few public meetings. The deadline has been extended to Wednesday, Feb. 18.

New national security challenges and advancement in technology make it necessary, the Navy said.

“Recent world events have placed the U.S. military on heightened alert in the defense of the U.S. and in defense of allied nations,” the Navy said.

The Navy started scoping meetings in 2007 to get input on its study for the training complex. The 60-day process started in July and included meetings held in September 2007.

The Navy received 50 comments, 23 of which expressed concerns or opposition to the training’s impact on marine mammals, such as whales.

Bruce Mate, the director of the marine Mammal Institute at Oregon State University, said in an e-mail the Navy plans to use high-energy sonar, up to 235 decibels. The National Marine Fisheries Service, he said, limits the sounds of human activities to no more than 160 decibels.

Editor Note: Mate does not seem to take into account that the sound pressure level decreases with range and the acoustic intensity decreases as 1/(range squared):

Navy Sonar and Marine Mammals off Hawaii

The U.S. Navy was granted a one-year permit to train with sonar and bombs in Hawaii waters so long as it tries to protect whales and other marine animals from harm. This is a controverial topic. It is covered in a full day in ATI’s course Advanced Topics In Underwater Acoustics.


  • Environmental Impact Considerations for Underwater Sound (Ellison) Anthropogenic sound impacts on marine animals. Permit requirements and process. US Federal Regulations, NEPA, MMPA, ESA, Magnuson-Stevens Act, Coastal Zone Management Act, National Marine Sanctuaries Act. International regulations and guidelines. Monitoring and mitigation.   
  • Marine Bioacoustics for Engineers (Ellison) Fundamentals of Marine Animal Hearing and Communication. Bioacoustic metrics. Acoustic exposure criteria for harm and significant behavior response for marine mammals. Developing criteria for fish and turtles. Behavioral testing techniques.