| Summary: | Minimal vessel traffic and cold water temperatures are believed to limit non-indigenous species (NIS) in high-latitude ecosystems. We evaluated whether suitable conditions exist in the Bering Sea for the introduction, survival, and reproduction of NIS. We compiled temperature and salinity thresholds of known NIS and compared these to ocean conditions projected during two study periods: current (2003-2012) and mid-century (2030-2039). We also explored patterns of vessel traffic and connectivity for U.S. Bering Sea ports. We found the southeastern Bering Sea had suitable conditions for the year-round survival of 80% of NIS assessed (n=42). However, only 52% of NIS had conditions suitable for reproduction or development (n=25). Conditions north of 58° N that include sub-zero winter water temperatures were unsuitable for the survival and reproduction of most NIS. While mid-century models predicted a northward expansion of suitable conditions, conditions for reproduction remained marginal. Within the highly suitable southeastern Bering Sea is the port of Dutch Harbor, which received the most vessel arrivals and ballast water discharge in the U.S. Bering Sea. Our findings illustrate the potential vulnerability of a commercially important subarctic ecosystem and highlight the need to consider NIS reproductive and developmental life phases when evaluating limits to their establishment. This data set includes the environmental suitability models that we created using three downscaled climate models (Regional Ocean Modeling Systems or ROMS) and species' temperature and salinity thresholds. We conducted these analyses for two, 10-year study periods: current (2003-2012) and future (2030-2039). For each species, we evaluated a) the number of weeks with suitable survival conditions; b) whether each species could survive year-round; and c) the number of consecutive weeks with suitable reproductive conditions. Looking for code? Head over to our GitHub repository: https://github.com/accs-uaa/bering-sea-marine-invasives
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