The Renewable Resources Report

Dr. Jason Gedamke Speaks on Anthropogenic Acoustic Impacts on Marine Mammals at Washington Round Table on Public Policy

GedamkeJason Gedamke, director of the Ocean Acoustics Program of the National Oceanic and Atmospheric Administration, hosted the RNRF Washington Round Table on Public Policy on May 30. He spoke about how marine mammals are impacted by the sounds from commercial shipping, oil and gas operations and sonar from U.S. Navy vessels.

NOAA works to understand ocean acoustics through research and data, and through the Ocean Noise Strategy Plan. The plan was released in 2016, and identifies NOAA’s long-term ocean noise management goals, as well as science and policy mechanisms for NOAA to meet those goals over the next ten years. Two mapping tools, CetMap and SoundMap provide data for analysis on the impacts of sound on marine mammals. The CetMap develops visuals to capture cetacean density and distribution to provide context for impact analyses while SoundMap maps man-made underwater noise from multiple sources.

Gedamke focused his talk on chronic impacts of acoustic disturbances on marine mammals, referring to the background anthropogenic noise in the ocean that limits marine mammals’ communication range and ability to sense their environment. These impacts include: degradation of communications among whales and other sea mammals, interference with predator avoidance, and navigational difficulties. He also spoke on the cumulative effects of ocean noise in ports, especially around Cape Cod, and the implications of that noise pollution for the endangered North American Right Whale.

He noted that acute impacts of brief but intense noise events are more understood by the scientific community and are reported more widely in the media. Acute impacts create an adverse physical or behavioral change in marine mammals that affects their health and fitness, which could include physiological injury, death and the stress or confusion that could lead to stranding events. While acute, dramatic events are important to study, relatively little is known about noise impact on a broader scale, and more must be done to monitor and collect data on levels of ocean noise. While marine scientists have constructed models to analyze ocean noise pollution, empirical data collection will be key to determining their predictive accuracy and how they can be improved.

With these challenges in mind, NOAA has several flagship programs aimed at understanding the impacts of ocean noise on and mitigating harm to marine mammals. The Ocean Acoustics Program is engaged in assessing long-term trends and changes in underwater soundscapes. It also has developed the collaborative work of the NOAA Noise Reference Station Network, which establishes and collects consistent and comparable long-term acoustic data sets across the U.S. to monitor low frequency, long-term passive acoustics.

Marine mammals are experiencing new pressures from multiple environmental changes, including overfishing, ocean temperature increases and acidification, and plastic pollution. The full range and long-term consequences of anthropogenic ocean noise are still not fully understood. However, current research confidently points to negative impacts.

Gedamke’s PowerPoint presentation may be accessed by clicking here.

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