Ringed seal (Pusa hispida) seasonal movements, diving, and haul-out behavior in the Beaufort, Chukchi, and Bering seas (2011–2017)

Continued Arctic warming and sea-ice loss will have important implications for the conservation of ringed seals, a highly ice-dependent species. A better understanding of their spatial ecology will help characterize emerging ecological trends and inform management decisions. We deployed satellite transmitters on ringed seals in the summers of 2011, 2014, and 2016 near Utqiaġvik (formerly Barrow), Alaska to monitor their movements, diving, and haul-out behavior. We present analyses of tracking and dive data provided by 17 seals that were tracked until at least January of the following year. Seals mostly ranged north of Utqiaġvik in the Beaufort and Chukchi Seas during summer before moving into the southern Chukchi and Bering Seas during winter. In all seasons, ringed seals occupied a diversity of habitats and spatial distributions; from near shore and localized, to far offshore and wide-ranging in drifting sea-ice. Continental shelf waters were occupied for >96% of tracking-days, during which repetitive-diving (suggestive of foraging) primarily to the seafloor was the most frequent activity. From mid-summer to early-fall, 12 seals made ~ one-week forays off-shelf to the deep Arctic Basin, most reaching the retreating pack-ice, where they spent most of their time hauled out. Diel activity patterns suggested greater allocation of foraging efforts to midday hours. Haul-out patterns were complementary, occurring mostly at night until April-May when midday hours were preferred. Ringed seals captured in 2011—concurrent with an unusual mortality event (UME) that affected all ice seal species—differed morphologically and behaviorally from seals captured in other years. Speculations about the physiology of molting and its role in energetics, habitat use, and behavior are discussed; along with possible evidence of purported ringed seal ecotypes.
Methods
********************************************************************************************************************

This data package contains tracking, haul-out, and dive data collected by Argos-compatible tags attached to 17 free-ranging ringed seals that were analyzed and presented in:

Von Duyke, A. L., Douglas, D. C., Herreman, J. K., & Crawford, J. A. 2020. Ringed seal (Pusa hispida)  seasonal movements, diving, and haul-out behavior in the Beaufort, Chukchi, and Bering seas (2011-2017). Ecology and Evolution, (accepted April 2020).

All tracking tags in this data package (n = 15) were manufactured by Wildlife Computers (Redmond, WA, USA). Data were acquired using the Argos System. Dive and haul-out data were extracted from the sensor fields in the raw Argos DS data using Wildlife Computer's DAP Processor 3.0 (Build 434). Two of the 17 seals carried tags built by the Sea Mammals Research Unit (SMRU), as described in the paper referenced above.

Data from the 2 SMRU tags are not in this data package; those data are planned for release at:  https://portal.atn.ioos.us/#metadata/ae1ea78a-2dbf-4294-908c-77580f92d5fd/project

********************************************************************************************************************