Department of Agriculture Division of Aquatic Wildlife Resources Fisheries Biologist Brent Tibbatts said a federal study shows there is a connection between stranded beaked whales in the Marianas Islands and the Navy's use of sonar.

"It's extremely unlikely that the two are not related that's kind of the point of the paper," he said. " It's showing 100% guaranteed that they're related."

The findings? The research reports the Marianas islands are a location where sonar-associated beachings of beaked whales occur. Beaked whales are especially sensitive to sonar use, studies have shown. The research shows that between August 2007 and January 2019, there were eight "stranding events." Each event involved one to three whales and three of these strandings occurred during or within six days following anti-submarine training conducted by the US Navy.

"The whales that were stranded here, just the ones that we get that come up on shore - it's possible that whales are being affected by this and they just drift out to sea and we never see them," Tibbatts said.



The study was conducted by the National Oceanic and Atmospheric Administration's pacific islands and southwest fisheries science centers. Tibbatts also provided data for the study. He said he expects sonar related beaked whale beachings to increase with the impending military buildup on the way.

"We anticipate that with the relocation going on these activities are only going to increase and so we'd like to see what could b done now to minimize the impacts that increase would have on the resources around here," he said.

But beaked whales aren't the only whales affected by Navy sonar use in the Marianas. Another NOAA study reports humpback whales frequent the Northern Mariana Islands.

"It was found recently that humpback whales use the Northern Marianas to give birth to and rear their calves and so because they are an endangered species in addition to being protected by the Marine Mammal Protection Act, activity in the water that may affect them - mitigation has to be described before any activities can happen there," he said. "That's another marine mammal species that could affect and will affect the use of sonar and other activities in the Northern Marianas."



The study used public sonar records and NOAA also had cooperation from the Navy. It found that the Marianas islands are home to at least three species of beaked whale. It also found the infrequent use of sonar may increase the severity of the reaction by beaked whales. The study shows beaked whales may change their normal diving behavior when coming across Navy sonar. This reaction may cause bubbles in their blood - similar to the "bends" divers get - and this may make whales more likely to get stranded. Research Sonar has also been shown to adversely affect dolphins as well.

Tibbatts said there are ways the military can mitigate sonar's damaging effects on marine mammals.

"Better testing for whales in advance of these sonar activities really to minimize the impacts that they could have on the whales," he said.

"In some places actually sonar use has been banned because of the relationship between the sonar use and the strandings of this particular species of whale."