Development of robust large whale satellite tags improves tag performance and reduces animal welfare problems

The use of satellite transmitters has yielded important information to better understand cetacean habitat use and to improve conservation and management. However, tag duration has been highly variable and typically shorter than battery life for most large whale species. Between 2011 and 2015, 65 transdermal satellite tags were deployed in Gulf of Maine (GoM) humpback whales (Megaptera novaeangliae) to assess tag impacts and to understand causes of tag rejection and tag failure. The strong fidelity of individuals to the GoM, long feeding ground residency, and high observer effort resulted in repeated sightings of animals instrumented with satellite transmitters. Multiple tag flaws were documented in early deployments, clearly indicating the urgent need for improvements in this methodology. These flaws not only resulted in short tag transmission durations, but also in negative physiological effects for individual animals. Modifications in the design and the manufacturing processes of these satellite tags were performed to resolve the observed flaws. These included (1) changes in the anchoring system tip, retention devices, and anchor articulation and (2) removal of the interface between the transmitter and the anchor. In addition, the use of novel 3D metal printing processes to manufacture integrated satellite tags resulted in significantly more robust designs (p=0.033). Deployments of these new tags resulted in significantly greater transmission duration (p=0.021) and in significantly lower probabilities of observing severe physiological reactions (e.g., persistent swelling, p = 0.012) when compared to flawed tags. This study highlights the importance of developing satellite tagging technology in association with observational studies and provides new tag designs that are structurally stronger and safer for use with large cetaceans.

Citation:

Zerbini, A., J. Robbins, R. Andrews, V. Andrews-Gof, M. Baumgartner, P. Clapham, M. Double, A. Kennedy, A. Leask, G. Schorr, S. Wilton. 2017. Development of robust large whale satellite tags improves tag performance and reduces animal welfare problems. Abstract (Proceedings) 22nd Biennial on the Biology of Marine Mammals, Halifax, Nova Scotia, October 22-27, 2017.