Publication Date:
2023-12-13
Description:
The relative contribution of regional contamination versus dietary differences to geographic variation in polar bear (Ursus maritimus) contaminant levels is unknown. Dietary variation between Alaska, Canada, East Greenland, and Svalbard subpopulations was assessed by muscle nitrogen and carbon stable isotope (d15N, d13C) and adipose fatty acid (FA) signatures relative to their main prey (ringed seals). Western and southern Hudson Bay signatures were characterized by depleted d15N and d13C, lower proportions of C20 and C22 monounsaturated FAs and higher proportions of C18 and longer chain polyunsaturated FAs. East Greenland and Svalbard signatures were reversed relative to Hudson Bay. Alaskan and Canadian Arctic signatures were intermediate. Between-subpopulation dietary differences predominated over interannual, seasonal, sex, or age variation. Among various brominated and chlorinated contaminants, diet signatures significantly explained variation in adipose levels of polybrominated diphenyl ether (PBDE) flame retardants (14-15%) and legacy PCBs (18-21%). However, dietary influence was contaminant class-specific, since only low or nonsignificant proportions of variation in organochlorine pesticide (e.g., chlordane) levels were explained by diet. Hudson Bay diet signatures were associated with lower PCB and PBDE levels, whereas East Greenland and Svalbard signatures were associated with higher levels. Understanding diet/food web factors is important to accurately interpret contaminant trends, particularly in a changing Arctic.
Keywords:
Age, relative, number of years; Alaska-Bering-Chukchi_Sea; Area/locality; Baffin Bay; BaffinBay-NE-Baffin_Is; Beaufort Sea; Bering Sea; Biological sample; BIOS; Comment; DavisStrait-SE-Baffin-Is; E-Greenland-Scoresby_Sound; Event label; Female, mature; Gulf-of-Boothia; Hudson Bay; Hudson Strait; International Polar Year (2007-2008); IPY; Isotope ratio mass spectrometry; Lancaster-Jones_Sound; Latitude of event; Longitude of event; Male, mature; N-Beaufort_Sea; North Greenland Sea; Northwestern Passages; Number; S_Hudson_Bay; Sample comment; Sampling date; S-Beaufort_Sea; Svalbard-BarentsSea; Time coverage; Ursus maritimus; W_Hudson_Bay; δ13C; δ13C, standard deviation; δ15N; δ15N, standard deviation
Type:
Dataset
Format:
text/tab-separated-values, 193 data points
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