<scp>Ringed</scp> Seal ( <scp> <i>Pusa hispida</i> </scp> ) Abundance in Isfjorden, Svalbard, After 20‐Years of Climate Change and a Concomitant Survey Hiatus

ABSTRACT Ringed seals ( Pusa hispida ) in Svalbard, Norway, are suspected to be declining due to a significant reduction in land‐fast sea ice, which serves as an essential breeding habitat, but were last surveyed in 2002. We address this data gap by conducting Uncrewed Aerial Systems (UAS) aerial surveys throughout Isfjorden (including adjacent small fjords) on the island of Spitsbergen, in the Svalbard Archipelago, during the molting season in 2023. We also provide an assessment of the size/age structure of the ringed seal population within Isfjorden using body lengths measured from aerial images. We show a decrease of 77% in land‐fast sea ice area and a concomitant decline in ringed seal abundance of approximately 46% since 2002. During the same period, the density of hauled‐out seals increased from 1.86 seals/km 2 in 2002 to 2.41 seals/km 2 in 2023. Length‐based estimates of age suggest that 65% of the contemporary population consists of immature individuals. Together, the results from this updated population survey underscore the need for more frequent monitoring of ringed seals in Svalbard to better understand the drivers of population decline and highlight the broader implications of environmental change on Arctic marine biodiversity. The innovative use of UAS technology in this study demonstrates its utility in wildlife research, offering a less invasive, more cost‐effective, efficient, and safer method for surveying marine mammals in polar regions compared to crewed aircraft.