Photographic evidence of tagging impacts for two beluga whales from the Cumberland Sound and western Hudson Bay populations

Kasey P Ryan,Steven H Ferguson,Cortney A Watt,Stephen D Petersen,C-Jae C Breiter

doi:10.1139/as-2021-0032

Abstract

Beluga whale ( Delphinapterus leucas (Pallas, 1776)) movements, habitat use, and diving behaviour have been studied using satellite-linked transmitters for decades. The inaccessibility of Arctic and subarctic habitats makes these instruments especially valuable for beluga research. The long-term effects that tags and tag attachments have on belugas, however, are not well known because resightings occur relatively infrequently. Here, we describe two belugas photographed during photographic monitoring programs of two populations: western Hudson Bay and Cumberland Sound. The beluga photographed in western Hudson Bay had scars consistent with the tag pins migrating out, which is thought to occur when the tag is pulled posteriorly due to drag. The beluga photographed in Cumberland Sound had all three tag pins still in place 11–21 years after they were inserted. Both whales appeared to be in good body condition with no evidence of infection, and the beluga from Cumberland Sound was accompanied by a 1-year-old calf. Resightings of previously tagged whales are infrequent for the western Hudson Bay population and have never been documented in Cumberland Sound. However, through long-term photographic monitoring programs, additional sightings may provide more information regarding the method of tag loss and the long-term effects of tagging on whale health and productivity.

Highlights

Deployments of satellite-linked transmitters are a common and effective way to monitor movements and dive behaviour of cetacean species over long periods of time and in areas that are largely inaccessible to researchers (Andrews et al 2019; International Whaling Commission 2020)
Photographic monitoring programs for beluga whales have been conducted in the western Hudson Bay (WHB) and Cumberland Sound (CS) populations since 2016 and 2017, respectively, to identify individuals and document behaviour, social associations, body condition, and habitat use
The scarring at the tag site indicated that the three tag attachment pins migrated out of the dorsal ridge due to hydrodynamic forces from drag that was created by the tag package during swimming

Summary

Introduction

Deployments of satellite-linked transmitters (hereafter referred to as “tagging”) are a common and effective way to monitor movements and dive behaviour of cetacean species over long periods of time and in areas that are largely inaccessible to researchers (Andrews et al 2019; International Whaling Commission 2020). Canadian Science Publishing (Quakenbush et al 2010; Hauser et al 2017; Mallory et al 2018) One such Arctic resident species is the beluga whale (Delphinapterus leucas (Pallas, 1776)). Reported resightings or recaptures of previously tagged belugas occur relatively infrequently; these events can provide useful information about individuals post-tagging. Such information includes the condition of the tag attachment site, survival, the method of tag loss, reproductive status, information about movement after tag loss, and further insight into the delineation between beluga whale populations as the movements of tagged whales between populations (or lack thereof) can be tracked (Sergeant and Brodie 1969; Orr et al 1998; McGuire et al 2021)

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Conclusion