Updates On Noise In The Oceans

Seismic surveys in Canada's Gulf of St. Lawrence could harm marine mammals, according to an expert panel's March assessment. The panel, convened by Quebec's environmental-assessment agency, BAPE, recommended minimizing the environmental impact of natural gas exploration in the seaway. Through public hearings and scientific research, BAPE will continue to investigate Hydro-Québec's controversial eight-year, $300-million oil and gas exploration project, and make a final report by the end of August.

SEMARNAT, Mexico's environmental protection agency, refused to permit a planned seismic exploration within Mexican waters by the R.V. Ewing. The project was stopped abruptly in March, when SEMARNAT received a full disclosure from a source outside of NMFS, of the noise levels, operation's profile, and numbers of marine animals projected to be impacted by the experiment. SEMARNAT had previously permitted the experiment, based upon an executive summary that was clearly less than the full story. Another seismic experiment scheduled to begin in late April is currently under review. Run by Scripps from the US Navy's R/V Roger Revelle, it will also use Mexican waters. Mexico is paying closer attention to the completeness of the background material.

The Advisory Committee on Acoustic Impacts on Marine Mammals will hold its second public meeting 28-30 April, in Arlington, Virginia. Hosted by the Marine Mammal Commission, the meeting is open to the public and will focus on techniques for risk assessment of acoustic impacts on marine mammals. It will include presentations on past and current risk analysis approaches, and on the Noise Exposure Criteria being developed by NOAA Fisheries. A draft meeting agenda and any background documents will be available on the Commission's web site at http://mmc.gov/sound/welcome.html. The Advisory Committee's third meeting is tentatively scheduled for 27-29 July in California.

CSI's president Bill Rossiter attended the first meeting, which brought together regulators, scientists, representatives from the military and shipping and energy industries, and environmental organizations, essentially a very diverse group of people who worked diligently to keep differences aside as they defined objectives and sought solutions to the growing problems of anthropogenic acoustical impacts, human noise in the oceans.

The vulnerability of beaked whales to anthropogenic sound was the subject of a Marine Mammal Commission technical workshop during mid April in Baltimore, Maryland. It reviewed beaked whale biology, and ecology and strandings, identified factors that may have caused those strandings, defined what research was needed to investigate possible cause-and-effect relationships, and recommended research, management, and mitigation strategies specific to beaked whales and acoustic impacts. For more information see http://mmc.gov/sound/beakedwhalewrkshp.html and http://www.mmc.gov/sound/.

"Shipping Noise & Marine Mammals: A Forum for Science, Management and Technology" will bring together scientists, regulators, maritime industry representatives and the interested public, 18-19 May 2004 in Arlington, Virginia. Attendance is free with advance registration via the symposium web site at http://www.shippingnoiseandmarinemammals.com/.

"Marine Animals and Human Noise" is a lecture series developed by NMFS, the Marine Mammal Commission, and scientists from various academic institutions, to increase public knowledge about human noise and marine mammals. Current scientific information about the physics of sound and hearing, as well as biological and behavioral factors that relate to human noise will be presented in eleven events in different locations that began in March and will continue until November. For information contact Connie Barclay, 301-713-2370, or go to http://www.nmfs.noaa.gov/ or http://mmc.gov/.

The US Navy destroyer USS Shoup on 5 May 2003 passed through Haro Strait, between Vancouver Island and San Juan Island, transmitting active sonar signals. Experienced observers noticed several marine mammals behaving abnormally during the transit, and several harbor porpoises were reported stranded. High quality recordings were made of the sonars, and one was identified as the C-53 sonar implicated in other stranding events. 14 harbor porpoises were reported stranded between 2 May and 2 June, well over the decade's average stranding rate of 6 per year.

Recently NMFS made their analysis of the controversial event public. The summary stated that "70 percent of the specimens were in moderate to advanced states of decomposition which made interpretation of the cause of death difficult. The cause of death was determined for 5 of the 11 porpoises examined by the multidisciplinary team. Of these five animals, two were found to have suffered blunt force trauma, while illness (peritonitis, salmonellosis, pneumonia) was implicated in the remaining three cases. No cause of death could be determined for the remaining six animals. The examinations did not reveal definitive signs of acoustic trauma in any of the porpoises examined. The possibility of acoustic trauma as a contributory factor in the mortality of any of the porpoises could not be ruled out. The multidisciplinary team noted that lesions consistent with acoustic trauma can be difficult to interpret or obscured, especially in animals in advanced post mortem decomposition."

The Navy's press release claimed that the report supported their claim that the sonars had nothing to do with the strandings. The full report gives reasons why so few of the animals were scanned in detail, and why the results were so inconclusive.