Open AccessSpatial and temporal variability in ringed seal ( Pusa hispida ) stable isotopes in the Beaufort Sea
Author(s) -
Boucher Nicole P.,
Derocher Andrew E.,
Richardson Evan S.
Publication year - 2020
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.6186
Subject(s) - trophic level , ecosystem , environmental science , oceanography , δ13c , arctic , sea ice , δ15n , population , marine ecosystem , apex predator , ecology , stable isotope ratio , biology , geology , physics , demography , quantum mechanics , sociology
Abstract Arctic ecosystem dynamics are shifting in response to warming temperatures and sea ice loss. Such ecosystems may be monitored by examining the diet of upper trophic level species, which varies with prey availability. To assess interannual variation in the Beaufort Sea ecosystem, we examined spatial and temporal trends in ringed seal ( Pusa hispida ) δ 13 C and δ 15 N in claw growth layers grown from 1964 to 2011. Stable isotopes were correlated with climate indices, environmental conditions, seal population productivity, and geographic location. Sex and age did not influence stable isotopes. Enriched 13 C was linked to cyclonic circulation regimes, seal productivity, and westward sampling locations. Higher δ 15 N was linked to lower sea surface temperatures, a higher percentage of pups in the subsistence harvest, and sample locations that were eastward and further from shore. From the 1960s to 2000s, ringed seal niche width expanded, suggesting a diversification of diet due to expansion of prey and/or seal space use. Overall, trends in ringed seal stable isotopes indicate changes within the Beaufort Sea ecosystem affected by water temperatures and circulation regimes. We suggest that continued monitoring of upper trophic level species will yield insights into changing ecosystem structure with climate change.