Satellite image survey of beluga whales in the southern Kara Sea

Abstract

The use of satellite imagery to find, count and monitor whales in remote and hard to access areas has shown some promise, but few satellite studies have, as yet, provided substantial conservation outcomes. Recent studies have shown the ability of very high‐resolution satellites to detect and count previously surveyed populations of belugas and narwhals in Canada. Here we describe the detection of a large aggregation of a poorly surveyed population of belugas in the southern Kara Sea, Russia, in a region where Soviet whaling is known to have had a heavy toll on belugas. We counted over 1,100 surface belugas using very high‐resolution satellite imagery. As only an unknown portion of the belugas can be seen on the surface, accurately converting the surface count to an abundance estimate will need further study, but using the analog of aerial surveys we estimate that this aggregation is between ~1,150–2,870 individuals. Although the species is not currently considered endangered, concern over belugas future population trends is increasing, as the species is reliant on Arctic sea ice, which is rapidly declining due to climate change. This study shows the utility of satellite imagery to discover and monitor new and little‐known cetacean populations.

Use of satellite imagery to estimate distribution and abundance of Cumberland Sound beluga whales reveals frequent use of a glacial river estuary

“…However, the specific use of these areas is still unknown. One study has used VHR imagery to infer beluga behavior by evaluating the positioning and orientation of beluga whales (Fretwell et al, 2023). In our study, there was no consistent directionality or positioning of whales, which may suggest that multiple behaviors are occurring in this critical habitat.…”

“…The use of satellite imagery to monitor cetaceans is increasing and is most often used for large whale species such as humpbacks, blue whales, fin whales, and right whales (Cubaynes et al, 2019;Hodul et al, 2023). However, VHR satellites such as Worldview-2 and -3, which provide images at 50 cm, 40 cm, and 30 cm resolution (a measure of pixel size), have been identified as a feasible method to study medium-sized cetaceans like beluga whales (Charry et al, 2021;Fretwell et al, 2023;Watt et al, 2023). Although satellite imagery has been used to estimate beluga whale abundance (Watt et al, 2023), to our knowledge, it has yet to be used to evaluate cetacean distribution or identify critical habitat.…”