Independent researchers working in coordination with the Navy ships USS Dewey (DDG 105) and USS Cape St. George (CG 71) conducted ground-breaking marine mammal behavioral response studies (BRSs) on the Navy's Southern California Offshore Range in July.
The studies occured July 8-12 with the destroyer Dewey and July 28-30 with the cruiser Cape St. George. During the studies, scientists attached data tags to a total of six marine mammals and tracked the animals' movements and behavior in response to sonar signals from the ships.
"USS Dewey was honored to be a part of this vital study. We take environmental stewardship seriously in our role as operators, and want nothing more than to be able to do our mission while protecting our environment," said Cmdr. Jake Douglas, commanding officer of USS Dewey.
While past behavioral response studies have used ocean research vessels with simulated sound sources, or depended on tagging of marine mammals during Navy at-sea training, these latest studies represent the first time U.S. Navy mid-frequency active sonar transmissions have been used for controlled exposure experiments on marine mammals.
"While playback studies and tagging during training exercises provide valuable data, BRSs that use real-time sonar from warships in a controlled experiment have great potential to help us understand how marine mammals are affected by Navy activities under realistic scenarios at sea," said Dr. Bob Gisiner, Naval Facilities Engineering Command (NAVFAC) program manager for the Navy's Living Marine Resources (LMR) Applied Research Program.
Using data tags with suction cups that can remain attached for 24 hours or longer, the team tagged two blue whales, two Risso's dolphins, a fin whale and a Cuvier's beaked whale.
The studies were authorized under permit #14534-02 from the National Marine Fisheries Service, issued July 2, 2010. The studies were also coordinated with the California Coastal Commission and the Channel Islands National Marine Sanctuary, and were endorsed by leading environmental groups.
The Navy began co-funding behavioral response studies in 2007 in partnership with NATO, academic institutions, private companies, the Joint Industry Program (JIP), and the Department of Defense Strategic Environmental Research and Development Program (SERDP). LMR and Office of Naval Research BRS teams have placed more than 100 tags on a variety of marine mammal species and safely conducted more than 50 experimental sound transmissions to measure marine mammal responses in Southern California waters, and have completed similar acoustic playback studies in the Bahamas, the Mediterranean Sea, Norway and other locations.
The Navy is currently seeking renewals of authorizations under the Marine Mammal Protection Act and the Endangered Species Act for activities in the Atlantic Fleet Training and Testing (AFTT) area and the Hawaii-Southern California Training and Testing (HSTT) area from 2015-19. Under the terms of its permits, the Navy integrates new data from BRSs and other studies as they become available during annual adaptive management discussions with the National Marine Fisheries Service.
To read the BRS scientists' blog, visit http://sea-inc.net/2013/07/26/begin-socal-13/.