9/11/16
Much about the elusive beaked whale remains a mystery to marine biologists, but that may soon change thanks to a West Coast research expedition by the National Oceanic and Atmospheric Administration.
Along the North Coast, only four to five beaked whales have been observed within the past few years according to Humboldt State University zoology professor and Director of the Marine Mammal Education and Research Program, Dawn Goley.
“Marine mammal population size has historically been measured by counting whales from boats during systematic surveys,” Goley said. “Beaked whales can be challenging to count because they are deep divers who spend long periods of time underwater far off shore. It’s not like seeing gray whales off the coast.”
Two NOAA chief scientists, Jeff Moore and Jay Barlow, are using a research survey called PASCAL, which stands for Passive Acoustic Survey of Cetacean Abundance Levels. The survey will take place on the ship Bell M. Shimada, which according to NOAA is a quieter vessel than older vessels used in the past. PASCAL will track and monitor beaked whales through a system of hydrophones, recorders that work underwater. The hydrophones will be placed on several buoys along a route from British Colombia to San Diego.
“There are a lot of mysteries still in the ocean and beaked whales are definitely involved in a lot of those,” Barlow said.
According to NOAA, the survey will be the first large-scale deployment of the listening buoys, developed at the Southwest Fisheries Science Center in San Diego. The buoys are expected to drift as much as 10 nautical miles a day and cover nearly 100 to 200 miles over a 20 day period.
Moore said the hydrophones listen for whales and as the buoys drift whale vocalizations are recorded for them to download and analyze during their expedition.
“We’ve deployed 22 hydrophones suspended 100 meters below the surface from buoys.” Moore said. “Collectively we’re sampling a much larger area and for longer periods of time than we’ve ever done. We expect to get many more audio detections across a larger array of habitats than we’ve ever been able to achieve.”
Barlow, who has been in charge of developing this acoustic technology for nearly two decades, said the system of studying and collecting these whale sounds is more innovative than using typical methods.
“There are seven different beaked whale species along the West Coast,” Barlow said. “Usually when we see one, we can’t determine what type it is. Through this research we plan to distinguish and identify them by the sounds they make.”
While the study expands outside of the California coast, Moore said the objective of PASCAL is to record acoustic data for deep diving species — like beaked whales — along the California current.
Moore and Barlow described their methods of monitoring these marine mammals as a novel study design, particularly when it comes to studying a perceived population decline in beaked whales.
“We’ll be able to learn more about where different species occur within the California current, and how many there are. After many years of developing these methods, we are finally able to implement them in a way to provide the information we’ve really wanted for a long time.” Moore said.
Additionally, the study would reveal how beaked whale species are responding to climate change and other oceanographic changes, including what Moore identified as a possible northern migration shift.
Goley said the method used by Moore and Barlow is an exciting prospect and that it will give researchers amazing insight into the biology of relatively unknown whales and their alleged decline.
“By using this passive acoustic technology, they will (...) have a better beaked whale population size estimate, which is a key component of any conservation effort,” Goley said.
