PEARL HARBOR –
A report released March 11 by the National Oceanographic and Atmospheric Administration's National Marine Fisheries Service (NOAA Fisheries) concluded that although the Navy's use of active sonar may have "induced a behavioral response," it was unlikely that the exposure caused any injury. The report was inconclusive on the subsequent stranding of 16 harbor porpoises in the area.
May 5, 2003, several civilian whale watchers vessels and local environmentalists observed orca along the shore of San Juan Island. During this timeframe, USS Shoup (DDG 86) was conducting routine training using its mid-range tactical sonar system. Although some statements in the media reported that the sonar had resulted in injury to the orca and was linked to subsequent harbor porpoise strandings, NOAA's assessment does not support these claims.
Harbor porpoise strandings in Puget Sound during May are an annual and seasonal event according to Conrad Erkelens, an environmental specialist for U.S. Pacific Fleet. Only one porpoise's stranding could potentially be linked in time to Shoup's active sonar use. However, it was discovered at a common stranding location, the stomach was empty as is typical for strandings in the region, and there was no evidence indicative of acoustic trauma.
Evidence from NOAA and others indicates that 2003 was a relatively normal year for porpoise strandings, according to Erkelens. He added that "there is certainly no indication from the NOAA report or from the Navy investigation that would lead us to believe that USS Shoup's sonar killed, injured, or otherwise harmed orca or harbor porpoise. In its study, NOAA Fisheries acknowledged the Navy's research, calling it "extremely thorough and detailed."
According to Erkelens, that falls in line with the Navy's history of working to protect marine mammals in the vicinity of naval activity.
The Navy is the foremost sponsor of marine mammal research in the world, and funds approximately 70 percent of U.S. research on the effects of human-generated sound on marine mammals and 50 percent of such research conducted worldwide. The Navy is committed to continuing that research in the future.
A full account of the Shoup incident is available at www.cpf.navy.mil/archive/report_release.htm.