Navy Continues its Commitment to Science through Marine Mammal Studies

FOR IMMEDIATE RELEASE

Navy Continues its Commitment to Science Through Marine Mammal Studies

WASHINGTON D.C., August 11, 2009 --/WORLD-WIRE/-- The U.S. Navy and its partners recently completed two studies that monitored marine mammal responses to military exercises. The studies were conducted from April 20 to May 20 on the Atlantic Undersea Test and Evaluation Center (AUTEC) in northern Bahamas, and from July 15 to July 28 on the Southern California Offshore Range (SCORE) off Coronado, California. Both studies used small dart tags with satellite transmitters to track the movements of whales before, during, and after exercises that included the use of active sonar. Additional data is being collected during biological and behavioral studies of marine mammals in the western Mediterranean Sea (MED-09) project underway since late July until early September.

"These studies are a major focus of the Navy's marine mammal research program, which is designed to understand the effects of anthropogenic sound on marine mammals," said Dr. Frank Stone, Navy's marine mammal program manager. "Follow-on studies are planned at AUTEC and SCORE, as well as the Navy's other at-sea ranges over the next five years."

The AUTEC study took place during a Submarine Commanders Course (SCC), and was performed by scientists from Naval Undersea Warfare Center (NUWC), the Bahamas Marine Mammal Research Organisation (BMMRO), and the NOAA Fisheries Southwest Fisheries Science Center (SWFSC). David Moretti, principal investigator for NUWC's Marine Mammal Monitoring Program, led the Navy's effort to use hydrophones to help determine behavior of whales on the range with and without active sonar present.

Moretti and his team monitored 93 hydrophones on the 500 nautical mile range. When a whale vocalization was detected, a research team deployed to the proposed location for satellite tagging, photo-identification and biopsy work.

(Satellite dart-tag on a Blainville's beaked whale. Photograph by Olivia Patterson, BMMRO.)

Nine satellite tags were successfully deployed on three different species on and around the AUTEC range, including three Blaineville's beaked whales, a Cuvier's beaked whale, and five sperm whales. Biopsy samples were also collected to obtain information on the genealogy, population structure and diet of the whales.

"The mere presence of these species on an active Navy range where sonar is used is counterintuitive to the perception of beaked whale reactions to sonar," said Moretti. "You wouldn't anticipate this species to be present if you believed the popular press."

Beaked whale monitoring during previous SCC events has shown a decline in acoustic detections of beaked whales during active sonar exercises. Researchers are still analyzing their data for this exercise, which they hope to utilize during a return to AUTEC later this fall.

The SCORE Marine Mammal Research Project involved collaboration between NUWC, SCORE, SWFSC, Cascadia Research, and Scripps Oceanographic Institution. Marine mammals were monitored over a 500 square nautical mile area using 83 hydrophones.

Eight marine mammals were successfully tagged, including a Cuvier's beaked whale, bottlenose dolphin, Risso's dolphin, and five fin whales. These tags supplemented data collected from one Cuvier's beaked whale and three fin whales tagged at SCORE in 2008.

"With each study, we're moving closer to answering the big questions relating to health of populations," said Moretti. "We've made great leaps from when the Navy started studying beaked whales 10 years ago. Back then we didn't even know what they sounded like, let alone the nature of their vocalizations. We now have preliminary data predicting how these animals move in sites of intense study, which we are beginning to interpret in an effort to answer those big questions."

Unlike SCORE and AUTEC, MED-09 tests are being conduced through controlled exposure experiments, in which the animals' behavior is measured before, during, and after specific sound exposures planned by the researchers, rather than sonar sounds generated during naval exercises. Researchers for this project include representatives from the NATO Undersea Research Centre, Woods Hole Oceanographic Institution, and other international scientific and academic organizations.

The results expected from MED-09 will contribute to a greater understanding of marine mammal biology in the western Mediterranean. Information regarding the baseline behavior of beaked whales and their response to manmade sounds will be integrated into Navy environmental planning for exercises, and also be made available to science organizations worldwide to support their research efforts.

For the entire article, see http://www.navy.mil/search/display.asp?story_id=47536

Contact:
Tracey Moriarty
(703) 604-5412