Year-round potential exposure of ringed seals to vessel traffic in the Pacific Arctic, 2013-2022

Arctic marine ecosystems are among the most rapidly changing on Earth. As sea ice has declined, vessel traffic has expanded into previously inaccessible areas also used by Arctic marine mammals, including ice-associated seals. To date, vessel exposure research has focused on cetaceans during the open-water season, but vessel traffic is also increasing during the ice-covered season, increasing the potential for exposure to ice seals. Ringed seals Pusa hispida depend on sea ice for reproduction and molting, critical periods when they may be particularly vulnerable to disturbances from vessels. We used vessel locations from the Arctic Ship Traffic Database and satellite telemetry locations for 27 ringed seals to estimate potential exposure (i.e. spatial-temporal overlap) to vessels by month in the Pacific Arctic, 2013-2022. Using a 125 km buffer around seal tracks to define monthly areas of potential exposure, 26 seals overlapped with vessels. There were 2172 total potential exposures (average 80, range 14-170 vessels per seal). Seals were potentially exposed to significantly more vessels during the open-water season when vessels traveled at significantly higher maximum speeds than during the ice-covered season. During the ice-covered season, 10 seals overlapped with 27 vessels, which included crude oil tankers, gas tankers, general cargo ships, and ’unknown’ and ’other’ vessel types. Our results suggest that ringed seals in the Pacific Arctic are regularly exposed to all vessel types during the open-water season; however, potential exposure during the ice-covered season is relatively low. Additional research is needed to understand the effects of vessel exposure on ringed seals.