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Teflon harness crossing on breast with a piece of leather. Bylot Island, NU 2014. Credit: Yannick Seyer.

Written by: Doug Sandilands

Center for Coastal Studies

Marine Animal Entanglement Response

Provincetown, MA

Entanglement in fishing gear is one of the major causes of injury and mortality to large whales worldwide. Professional entanglement response teams around the world have come to rely on ARGOS based telemetry, via a tag and buoy system that is attached to the entangling gear and pulled by the whale, to aid in successful disentanglements and keep responders safe.

The Center for Coastal Studies (CCS) Marine Animal Entanglement Response (MAER) team out of Provincetown MA conducted its first organized whale disentanglement in 1984 and has since disentangled over 250 large whales; approximately 80% of humpback and right whales in the northwest Atlantic have been entangled at least once. 


Over the last 30 years, the MAER team has faced many challenges posed by the complexity of the entanglement, the evasiveness of the animal, weather conditions, and diminishing daylight.  Entanglements are often reported late in the day or far off-shore, such that responders are sometimes unable to complete a response in a single day.


Further, relocating an entangled whale just by searching is extremely unlikely.  As a result, prior to having telemetry as an option teams often felt compelled to do something as quickly as possible, knowing that if they didn’t the whale would not likely survive its entanglement. Safe entanglement responses require well thought out decisions and deliberate actions.

Recognizing this, in the late 1990’s, CCS and the Atlantic Large Whale Disentanglement Network (ALWDN), working with Telonics Inc (of Meza, AZ), developed an ARGOS/CLS-based satellite tag and buoy system that could be attached to the gear entangling a whale, in order to track the whale when a disentanglement can not be completed in a single day.

The tag and buoy were designed to be pulled to a depth of 600 meters and minimize the effort required by the whale to pull the buoy through the water (drag) and underwater (buoyancy), while keeping the antenna pointing upright and high enough above the water (when the whale/buoy is at or near the surface) to ensure transmissions to the ARGOS satellites are successful.

The ARGOS system and telemetry buoy allows entanglement response teams to conduct an entanglement response when conditions are favorable to ensure a successful outcome: the responders all remain safe, all life-threatening gear is removed from the whale and documentation collected during the response contributes to efforts to prevent entanglements. Additionally, tracking information from telemetry can also provide insight into the entangled whale’s movement and behavior. To date, the ALWDN has deployed the ARGOS buoy system on over 35 whales to aid in disentanglement attempts.

To learn more about the Center for Coastal Studies and the MAER team go to

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