Developing robust large whale satellite tags through follow-up studies

The use of satellite tags has yielded important information to better understand cetacean ecology and to improve cetacean conservation. However, tag deployment duration has been highly variable and typically shorter than their battery life on most large whale species. Between 2011 and 2018, 80 consolidated satellite tags were deployed in North Atlantic humpback whales (Megaptera novaeangliae) in the Gulf of Maine (GoM) to study whale movements, to assess tag impacts, and to understand causes of tag rejection and tag failure. The strong site fidelity of individual whales to the GoM, long feeding ground residency, and high observer effort allowed repeated sightings of animals instrumented with satellite tags. In early deployments multiple structural deficiencies were documented on the tags, revealing the need to improve the mechanical design and manufacturing of the instruments. These tag deficiencies not only resulted in short tag transmission durations, but also in negative health impacts on individual animals. Incremental modifications to the mechanical design and the manufacturing processes to resolve the observed deficiencies included: (1) changes in the anchor tip, retention devices, and anchor articulation, (2) the removal of the interface between the transmitter housing and the anchor and (3) the redesign of the posterior end of the tag. More robust instruments were produced by welding deficient tag parts or by using 3‐dimension (3‐D) metal printing processes to manufacture integrated instruments. Deployments of redesigned satellite tags resulted in 65–85% significantly longer average transmission durations when compared to earlier designs that showed structural deficiencies. This study highlights the importance of developing satellite tagging technology in association with follow‐up monitoring of tagged individuals and provides new tag designs that are structurally more robust and less impactful for use with large cetaceans.