Harbor Porpoise/Navy Sonar Investigation

In addition to improving the health of marine wildlife and ecosystems by funding critical research and bringing stakeholders together, the SeaDoc Society also provides all levels of scientific support for numerous regional marine ecosystem health-related issues. A good example is our participation in the recent investigation of the potential association between the stranding of 14 harbor porpoises and the Navy’s mid-frequency sonar exercise in Haro Strait last May.

Because of our reputation for conducting unbiased scientific research and our extensive knowledge of diseases of wildlife, NOAA Fisheries asked the SeaDoc Society to help conduct an extensive classical forensic necropsy of each of these harbor porpoises last summer. Joe Gaydos spent numerous hours examining animals, reviewing test results, and preparing the recently released report. The results of all the testing were inconclusive. We were able to determine the cause of death for five of the 11 animals examined, but a cause of death could not be determined for the other six. None of the 11 animals examined had definitive signs of sonar-related trauma, but this didn’t rule out the possibility that sonar-related trauma could have been involved in the deaths of some of these animals. Signs of sonar-related trauma can be difficult to diagnose, especially in decomposed carcasses, and due to the condition of some animals, the potential involvement of sonar-related injury as a contributory factor in the deaths of some porpoises could not be completely ruled out.

Despite the fact that many people wanted the investigation to incriminate or exonerate the Navy, that is not what this investigation or the SeaDoc Society is about. We are about using the best science available to make the best decisions possible. In the case of mid-frequency sonar and marine mammals, it is clear that we still need to be attentive to the issue and make concerted efforts to learn more. Hearing is very important to marine mammals and it is clear that in order to balance the needs of homeland security and the needs of marine mammals, we need to proceed cautiously while doing more work to better understand acoustic trauma in marine mammals.

Once again, the valuable contribution of the SeaDoc Society is this work would not be possible without private citizens like you who care enough about our marine ecosystem to invest in its future. For more detail about the harbor porpoise investigation please contact us or visit NOAA Fisheries website at http://www.nwr.noaa.gov.

Thanks again for your support.


Kirsten V.K. Gilardi, DVM, Dipl. ACZM Program Coordinator

Joseph K. Gaydos, VMD, PhD Staff Scientist