Navy Conducts Marine Mammal Study off Cape Hatteras
06 August 2021
NORFOLK, Va --
The guided-missile destroyer USS Farragut (DDG 99) recently supported a U.S. Fleet Forces Command-funded project designed to increase understanding of the effects mid-frequency active sonar may have on marine mammal behavior.
The Farragut crew assisted while multiple Cuvier’s beaked whales were tracked off Cape Hatteras during a Behavioral Response Study Controlled Exposure Experiment (CEE) under the guidance of Navy personnel from USFF and scientists from Duke University and Southall Environmental Associates July 30.
“This experiment, in particular, was a huge success due to the Farragut,” said Ron Filipowicz, Acoustics/Operations Support Specialist at USFF. “The level of support and coordination was truly outstanding.”
The Farragut’s support for the project entailed use of active sonar at a specific time and location so that the researchers could monitor the reaction of the marine species.
“This is not an easy thing for a ship to do, and the Farragut supported us tremendously,” said Filipowicz. “Not only did the commanding officer and wardroom make it easy to prepare for the experiment through constant and effective communications with myself and the science team, the crew executed the experiment flawlessly under demanding sea conditions, which allowed us to collect a highly important dataset of information.”
“Our experiments involve first locating and tagging focal individuals, monitoring their behavior for an extended period before the exposure through data from the tags obtained through satellites or in the field, relocating some individuals and tracking them visually for periods just prior to, during, and after the CEE, presenting the sonar stimulus in a controlled and strategic way to meet research goals, and monitoring their behavior directly for an extended period of time after the CEE,” said Brandon Southall, the leader of this experiment.
Southall is a research biologist and a marine bioacoustician who specializes in studying the sounds ocean animals make, and how their hearing and behavior can be affected by noises from human activities.
There can be many obstacles to successful completion of these types of experiments, and Southall said sea state presented challenges to this one.
“Weather and sea conditions can be challenging, as they were in this event, especially in a site such as Hatteras where the animals and researchers are 30 or more nautical miles offshore and fully exposed,” he said. “Tagging these kinds of whales requires boats that are large and robust enough to get this far offshore safely but also small and agile enough to safely and effectively approach sometimes fast-moving and maneuverable animals.
“The tags record information from the animal, such as its position, as well as the acoustic information from the Navy ship that is transmitting the active sonar,” said Filipowicz. “That information is recovered from retrieved tags or is sent up to a satellite which is then transmitted back to a receiver that the scientific team has to record the data.
“There are protocols in place for aiding with the safety of the tagging vessels and personnel as well as the mammals, ensuring they are not disturbed in a harmful way,” he said.
All of the data collected is shared with the National Marine Fisheries Service and other scientific organizations of interest.
“Our scientific data is freely available to any scientific organization and we publish it specifically for use in environmental analyses and permits.” said Filipowicz. “The National Marine Fisheries Service, as a cooperating agency, cooperates with our environmental impact studies and they issue our permits to us. So, whatever science we use they use and vice versa.”
Southall indicated that the participants in the exercise required very specific skillsets.
“These require both very skilled drivers to put the tagger in the correct place as well as talented and careful taggers to place them in safe and effective locations on whales. It is hard and many times the conditions and the whale behavior do not allow successful tagging,” he said.
“However, we tagged nearly 100 whales in the current project over the past 4 years, most of them being the highest priority species - Cuvier’s beaked whales. These whales can stay underwater for two hours or more, at depths of two miles or more, and can cover large distances underwater, staying at the surface for just a few minutes at a time.”
Southall indicated that although the data gathered during this CEE is still being analyzed, initial indications are that the project was very successful.
“While we are still in the data-collection phases of the project, we have documented a number of clear responses,” he said. “As with people, there is a diversity of responses in instances where whales encounter sonar. Some exhibit no clear behavioral responses in conditions where others may respond and we are working out some of the contextual reasons (meaning co-variates like where the sonar is relative to them) of why beyond the most simple description of how loud it is.
“But we have seen, including with the outstanding CEE conducted last week with the Farragut (perhaps the most successful in the course of this or arguably any of the Navy-supported BRS-efforts), clear avoidance responses (animals move away from the source, sometimes very rapidly), interesting changes in diving behavior (shorter or sometimes extended or unusual dives, cessation of foraging), and sometimes orienting behaviors where animals appear to be looking and/or listening around,” he continued. “Some of these responses are similar to those measured in other studies but we are amplifying these with such large sample sizes in this highest priority species and adding important new insights.”
This study has been ongoing since 2017, with field work typically occurring from May through August. Although the Navy tries to support three to four CEEs each summer, schedules can be impacted by weather, ship availability, and the presence (or absence) of whales. This year, four have been tentatively planned, with this being the first completed.
“In order to ensure that the best available science is continually developed and maintained, these types of studies are essential for us to complete our required environmental impact studies and mitigate impacts to marine species while we conduct our essential training activities,” Filipowicz said. “There is no other way to conduct this science other than through the collaborative effort of the scientific, academic, regulatory, and military communities working together.”
Southall indicated he was especially eager to participate in this CEE with the USS Farragut, because of a family connection to the name.
“My grandfather, Berle Southall, was stationed at the Farragut Naval Station in Idaho during WWII and served as a training officer for submarine and other vessel operations there - they trained in the lake,” he said. “My father, who was born there in 1944 while my grandfather was stationed there, went on to become a Lt.Col in the U.S. Air Force. When I heard we were going to be working with the Farragut, I told my dad about the connection, and he told me some more details about my grandfather’s time there.
“During the CEE I did think about that and especially I thought about those young people in training and that on the Farragut there were probably some pretty young new Sailors there,” he continued. “I wondered what they must have thought about what we were doing together and why and what it meant. I hope they might realize that in that moment the Navy and biologists working to understand and help conserve marine life were coordinating and working together to get better real data to help the Navy do what they need to do to help sustain these amazing animals.”
The Navy’s Marine Species Monitoring Program is responsible for supporting environmental compliance requirements under the Marine Mammal Protection Act and Endangered Species Act. The program funds monitoring projects focused on a variety of marine species related to occurrence, exposure, and response relative to training and testing activities. The Atlantic BRS is the first significant transition from the Navy’s Living Marine Resources Program, which has supported development of behavioral response studies and methods for over a decade. More information on the Marine Species Monitoring Program can be found at the program’s web portal - https://www.navymarinespeciesmonitoring.us