GLOUCESTER, Mass. — Marine biologists are deploying specialized tags to better understand the behavior and communication patterns of humpback whales. The digital acoustic recording tags, known as DTAGs, are attached to the whales using suction cups, allowing scientists to monitor the animals without disrupting their natural behavior.
The DTAGs record sound and movement data, providing researchers with critical insights into the whales’ underwater activities. “This technology allows us to study how humpbacks communicate, navigate, and respond to environmental changes,” said Dr. Megan Roberts, a lead researcher with the Marine Conservation Institute. The tags collect information on everything from whale songs to feeding habits, along with how the whales react to ship noise and other disturbances.
The tags, which can remain attached for up to 48 hours, capture detailed three-dimensional movements and surrounding sounds as whales dive and forage. “With this data, we can also better understand the impact of human activity on whale populations,” Roberts said, emphasizing the importance of the study in protecting these endangered marine mammals.
The tagging process is conducted with minimal intrusion, as researchers approach the whales from boats and attach the DTAGs using a long pole. Once the tags naturally detach, they float to the surface and are retrieved by the team for data analysis.
There have been four generations of DTAGs since they were first developed in 1998 at Woods Hole Oceanographic Institution, with decreasing size and increasing capabilities each generation. DTAG-4 is the latest version that is being used and tested by the team, and is small enough to hold in the palm of your hand.
These newer tags also provide fine-scale information about the sound range and behavior of whale species. When whales pass by stationary passive acoustic monitoring devices in the ocean, an underwater microphone records their song and vocalizations. However, this passive acoustic data is not fine-scale enough to know which individual in a group of whales is making those sounds. In 2022, Cusano, Wiley, and colleagues tagged 12 endangered sei whales in the first ever study using acoustic tags to document the calling behavior of sei whales in feeding grounds. The success of this study shed light on the usefulness of this particular tagging technology to identify which individual animal is calling.
Taking this a step further, the team is now using “group tagging”—a method of tagging multiple individuals from a single group to distinguish which animal is making specific vocalizations.
To date, biologging tags have provided important information for many species of large whales, including humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), sperm (Physeter macrocephalus), sei (B. borealis), North Atlantic right (Eubalaena glacialis), fin (B. physalus), and minke (Balaenoptera acutorostrata) whales.
The study is part of broader efforts to conserve whale populations and maintain ocean biodiversity. Humpback whales, known for their complex vocalizations and impressive migrations, are a critical focus of global marine conservation initiatives.
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