High-Tech Tags Help Researchers
Understand Whale Behavior

by National Marine Sanctuaries

This 3-D image helps researchers better understand whale behavior underwater. (Photo: SBNMS/UNH)

Begun two years ago, the study is significant not just for purely scientific reasons. Despite warning networks and fishing gear modifications, whales continue to die because of ship collisions and entanglements with fishing gear. "Understanding their feeding behavior and water column use may lead to changes in shipping practices and/or changes in the nature and deployment of fishing gear," says Wiley.

Collecting the data requires a multi-step process, including locating and tagging appropriate animals. Humpbacks are not easy subjects to study because they spend little time at the surface. Using the research vessel's motorized inflatable boat and a 45-foot flexible pole, the researchers quickly approach the surfacing whale and place a benign suction-cup recording device, known as a D-Tag, on its back. This device captures whale movement, sound and depth.

After retrieving the tag, usually within 24 hours after placement, researchers analyze data from the device and use revolutionary visualization software developed at the University of New Hampshire to replicate the whale's movements. The tracks show whales diving to the bottom, turning on their sides, and possibly foraging at or near the seafloor. This behavior can put an animal in direct contact with lobster and gill net gear, including the vertical lines that attach to fl oats at the surface and floating horizontal lines that string between lobster pots. Such encounters may result in life-threatening entanglements.

"With our information, we have suggested that lobster fishermen sink the lines between pots along the bottom, rather than have them hover above the seafloor," says Wiley. "This method is much safer for the whales because it lessens the risk of their getting entangled."

Wiley's research also reinforces the importance of an established federally-funded program sponsored by the state of Massachusetts and the International Fund for Animal Welfare to buy back old fishing gear from fishermen so they can purchase newer, safer ones.

"Thanks to new technology like the D-Tag, we're obtaining information about whale behavior that we simply couldn't get before," says Wiley. "And that helps us help them."

Special software developed at the University of New Hampshire translates data recorded by the D-Tag into an image showing the whale's movements. (Photo: SBNMS/UNH)