Active Military Sonar and Marine Mammals: Events and References

• Main Authors: Buck, Eugene H., Calvert, Kori
• Other Authors: LIBRARY OF CONGRESS WASHINGTON DC CONGRESSIONAL RESEARCH SERVICE
• Format: Text
• Language: English
• Published: 2005
• Subjects: Biology; Undersea and Antisubmarine Warfare; Acoustic Detection and Detectors; Noise Pollution and Control; *NAVY; *ENVIRONMENTAL IMPACT; *SONAR SIGNALS; *AQUATIC ANIMALS; *LEGISLATION; *LITIGATION; *LOW FREQUENCIES; *INTERMEDIATE FREQUENCIES; NATO; UNITED STATES GOVERNMENT; HISTORY; HIGH INTENSITY; HEARING; SONAR ARRAYS; REACTION(PSYCHOLOGY); NOISE POLLUTION; LITTORAL ZONES; AGREEMENTS; MILITARY EXERCISES; PHYSIOLOGICAL EFFECTS; STRESS(PSYCHOLOGY); GOVERNMENT(FOREIGN); *ACTIVE SONAR; *CHRONOLOGIES; COURT DECISIONS; MMPA(MARINE MAMMAL PROTECTION ACT); LFA(LOW FREQUENCY ACTIVE); SURTASS(SURVEILLANCE TOWED ARRAY SENSOR SYSTEM); NMFS(NATIONAL MARINE FISHERIES SERVICE); ENDANGERED SPECIES ACT; NEPA(NATIONAL ENVIRONMENTAL POLICY ACT); LWAD(LITTORAL WARFARE ADVANCED DEVELOPMENT PROGRAM); NRDC(NATIONAL RESOURCES DEFENSE COUNCIL); WHALE STRANDINGS; ENVIRONMENTAL GROUPS; OCEAN NOISE; baleen whales
• Online Access: http://www.dtic.mil/docs/citations/ADA472654; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA472654

The deployment of active sonar by the U.S. Navy and its potential impacts on marine mammals has been an ongoing issue of intense debate; regulatory, legislative, and judicial activity; and international concern. Some peacetime use of military sonar has been regulated under the Marine Mammal Protection Act (MMPA) and other statutes due to concerns that active military sonars are operated at frequencies used by some cetaceans (i.e., whales, porpoises, and dolphins), and their high-intensity sound pulses may travel long distances in the ocean. There also is concern that sonar transmissions of sufficiently high intensity might physically damage the hearing in cetaceans or cause them to modify their behavior in ways that are detrimental. Although mid-frequency sonar has been implicated in several beaked whale strandings, there is scientific uncertainty surrounding the totality of the effects active sonar transmissions may have on marine mammals. This report summarizes legal and political events related to active sonar and marine mammals since 1994. Prior to the late 1990s, concerns focused primarily on the use of underwater sound as a research tool. While strandings and mortality of marine mammals have been observed in concurrence with mid-frequency sonar operation, additional controversy has focused on the development of low-frequency active (LFA) sonar. Environmental interests are concerned with LFA sonar because low-frequency sound travels farther than mid-frequency sound and is closer in frequency to those known to be used by baleen whales. Additional questions involve how to balance obligations of the military to comply with MMPA provisions (as well as provisions of the National Environmental Policy Act and the Endangered Species Act) with national security concerns. This report summarizes some of the more significant recent events pertaining to the environmental effects of active military sonar. CRS Report for Congress.