Long-term tracking of whale feeding behavior via satellite is now possible thanks to a new tag

NEWPORT, Ore. — Researchers at Oregon State University have developed a new satellite beacon that allows them to better track whale behavior, including previously unobservable feeding events during dives.

The tag is a significant advance in researchers’ ability to observe key events in whale behavior, identify important habitat, and better understand whale response to human activity such as shipping traffic or military sonar. said Daniel Palacios, associate professor in whale habitats at OSU’s Marine Mammal Institute. For the past 30 years, the institute has been a leader in the development and use of satellite tagging of whales.

As shipping traffic increases, whales around the world are at increased risk of being struck by large vessels. The top 30 meters of the water column – the vertical expanse that stretches from the surface of the water to the bottom of the ocean – is considered the “danger zone” for whales crossing the waterways. navigation.

“One of the benefits of these new tags is that they give us information about how long whales spend in the danger zone throughout their migration,” Palacios said. “With this information, we can identify high-risk areas and make more informed decisions to help protect them from the threat of ship strikes.”

The ability to monitor diving behavior and detect changes could also have applications for measuring how whales respond to sources of loud sound, such as sonar used by the US Navy, he added.

The tag, known commercially as RDW, could also have applications in new areas of research, including the physiology, behavior, ecology and conservation of marine mammals. The features and benefits of the new tag are described in a recently published article in the journal Animal Biotelemetry.

“Studying anything, whether it’s a plant, an animal, or even something like our solar system, relies on our ability to observe it,” the co-author said. article, Ladd Irvine, senior research assistant at the Marine Mammal Institute, part of OSU. College of Agricultural Sciences.

“Whales spend the vast majority of their lives underwater, where we cannot see them. They can travel over 100 kilometers in a day, so typical sighting methods are unreliable for knowing where they are going or what they are doing. Beacons allow us to ride with whales as they go about their lives, like a fitness tracker or smartphone app.

In the past, technological limitations have prevented long-term monitoring of whale feeding behavior. When feeding at the slit, a whale dives deep and consumes a large amount of prey and water, then filters the water. Previous satellite tracking devices could monitor their horizontal movements, but not their diving behavior.

Working in partnership with manufacturer Telonics, Inc., Oregon State researchers developed the new RDW tag to incorporate pressure and accelerometer sensors that will allow them to monitor more whale movements, including feeding. by slot, via satellite for several months.

The beacon software creates a behavior summary for each dive and transmits the data via satellite. The software also adapts over time to better detect key events in the accelerometer data.

“This new system allows us to monitor the feeding behavior of baleen whales over much longer periods of time than was previously possible with other types of tags,” Irvine said. “In the past, we’ve been able to monitor the whales’ long-term movements, but this additional information helps us better understand what they’re doing at these 3D locations.”

The new tags, which are implanted in whale blubber, were tested on 14 blue whales and 14 humpback whales off the coast of Southern California. The data collected from the tests was similar to what a simulation produced, confirming their effectiveness.

Former Marine Mammal Institute director Bruce Mate is a co-author of the paper. Mate, now retired, pioneered the study of whale movements using satellite tags in the late 1980s. The new tag is a direct result and progression of Mate’s work, said Palaces.

“Before the advent of tagging, we could only get a glimpse of whale life when they surfaced or by tracking individuals for a few hours at a time,” Irvine said. “It was like trying to watch a theater production in the dark, where someone turned on the lights for a few seconds every now and then. Following the whales for weeks, months and even over a year of their lives , we are now able to paint a more complete picture of whale life.

Additional co-authors include Barb Lagerquist of the Marine Mammal Institute; James Fahlbusch of Hopkins Marine Station at Stanford University; John Calambokidis of the Cascadia Research Collective and Stanly Tomkiewicz of Telonics, Inc.

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