Satellite-Linked Tag Improves Long-Term Whale Tracking
Researchers can monitor whales more effectively with the new RDW tag developed by Oregon State University.
Whales around the world have a higher risk of being hit by a ship due to increased shipping traffic. Oregon State University researchers developed a satellite tag for improved crucial habitat identification and tracking of a whale's behavior, like feeding while diving. The advancement also helps to understand their response to human activity, such as a passing ship or military sonar.
"One of the benefits of these new tags is that they give us information about how much time whales are spending within the danger zone throughout their migration," said Daniel Palacios, associate professor in whale habitats at OSU's Marine Mammal Institute "With that information, we can identify areas of higher risk and make more informed decisions to help protect them from the threat of ship strikes."
Previously limited technology made it difficult to track a whale's feeding behavior. Generally, whales dive deeply while lunge-feeding, consuming a huge amount of prey and water. Initial satellite devices monitored their horizontal movements without considering their behavior while diving.
Their novel RDW tag is equipped with an accelerometer and pressure sensors integrated that can track a whale's movements for several months via satellite. The tag's software generates a behavior summary during each dive, sending the data by satellite. Additionally, the software adapts for improved key event detection in accelerometer data. The team performed tests on these tags implanted in 14 blue and 14 humpback whales from the southern California coast. They discovered that the data showed similar results as a simulation, which verified their effectiveness.
"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," paper co-author Ladd Irvine explains. "In the past we've been able to monitor the long-term movements of whales, but this additional information helps us better understand what they are doing in those places in 3D."