Using claws to compare reproduction, stress, and diet of female bearded and ringed seals in the Bering and Chukchi seas, Alaska, between 1953-1968 and 1998-2014.

Rapid climate warming is decreasing sea ice thickness, extent, and duration. Marine mammals such as bearded (Erignathus barbatus) and ringed (Pusa hispida) seals, which use sea ice for pupping, molting and resting, may be negatively affected. Claws from bearded and ringed seals store up to 14 and 12 years of sequential analyte data, respectively. These data can be used to compare reproduction, stress, and diet across decades. In this study, we compare progesterone, cortisol, and carbon and nitrogen stable isotopes in female bearded and ringed seals during 1953-1968 (pre-1968, a period prior to sea ice decline) to 1998-2014 (post-1998, a period during sea ice decline). When comparing these periods, bearded seals had statistically higher cortisol concentrations post-1998, and for both species δ13C was more negative post-1998, while progesterone and δ15N did not change. There was a positive relationship between progesterone and cortisol Z-scores for both species, except for ringed seals post-1998. There was a negative relationship between cortisol Z-scores and δ13C for bearded seals evident in post-1998 indicating that higher cortisol Z-scores are associated with more negative δ13C in bearded seals in recent years. This negative relationship between cortisol and δ13C in bearded seals suggests a shift to higher prey diversity, possibly due to changes in sea ice in the Pacific Arctic evident post 1998. Progesterone Z-scores corresponded to expected differences among non-pregnant, unimplanted, implanted, and post-partum individuals. Using these data, pregnancy history was determined for reproductive years for each individual female sampled which could allow for yearly pregnancy rates to be calculated given a large enough representative sample of the population. These results combine decades of observational studies with hormones and stable isotopes to infer changes in reproduction, stress, and diet, as well as the connection between these life history parameters.

Rapid climate warming is decreasing sea ice thickness, extent, and duration. Marine mammals such as bearded (Erignathus barbatus) and ringed (Pusa hispida) seals, which use sea ice for pupping, molting and resting, may be negatively affected. Claws from bearded and ringed seals store up to 14 and 12 years of sequential analyte data, respectively. These data can be used to compare reproduction, stress, and diet across decades. In this study, we compare progesterone, cortisol, and carbon and nitrogen stable isotopes in female bearded and ringed seals during 1953-1968 (pre-1968, a period prior to sea ice decline) to 1998-2014 (post-1998, a period during sea ice decline). When comparing these periods, bearded seals had statistically higher cortisol concentrations post-1998, and for both species δ13C was more negative post-1998, while progesterone and δ15N did not change. There was a positive relationship between progesterone and cortisol Z-scores for both species, except for ringed seals post-1998. There was a negative relationship between cortisol Z-scores and δ13C for bearded seals evident in post-1998 indicating that higher cortisol Z-scores are associated with more negative δ13C in bearded seals in recent years. This negative relationship between cortisol and δ13C in bearded seals suggests a shift to higher prey diversity, possibly due to changes in sea ice in the Pacific Arctic evident post 1998. Progesterone Z-scores corresponded to expected differences among non-pregnant, unimplanted, implanted, and post-partum individuals. Using these data, pregnancy history was determined for reproductive years for each individual female sampled which could allow for yearly pregnancy rates to be calculated given a large enough representative sample of the population. These results combine decades of observational studies with hormones and stable isotopes to infer changes in reproduction, stress, and diet, as well as the connection between these life history parameters.

Disciplines

Cross-discipline, Environment

Keywords

bearded seals, ringed seals, ice seals, cortisol, progesterone, pregnancy, claws, stable isotopes

Data

FileSizeFormatProcessingAccess
HormonesSI_avg
75 KoCSVProcessed data
HormonesSI_combo_FINAL
173 KoCSVRaw data
HormonesSI_combo_FINALprog
6 KoCSVRaw data
HormonesSI_knownagecortonly_noNAs
33 KoCSVRaw data
HormonesSI_Suesscor_noNAs
150 KoCSVProcessed data
IceSealClaws_cort_noNAs
87 KoCSVRaw data
IceSealClaws_prog_updatepregstats
147 KoCSVProcessed data
IceSealClaws_prog_updatepregstats_W0only
7 KoCSVProcessed data
IceSealClaws_prog_updatepregstats_W0only_noNAs
6 KoCSVProcessed data
IceSealClaws_prog_updatepregstats_W0only_Season_noNAs
6 KoCSVProcessed data
IceSealCortisol_W0only
2 KoCSVRaw data
cort_years_figuresbyspecies
3 KoTEXT
figures_pregs
3 KoTEXT
IceSealClaws_lme_analyses
28 KoTEXT
IceSealClaws_preg_pre_post
3 KoTEXT
IceSealClaws_preg_season
6 KoTEXT
IceSealClaws_pregstage_season
2 KoTEXT
IceSealClaws_Supplementary
6 KoTEXT
IceSealprog_Zscore
2 KoTEXT
youngseal_cort
2 KoTEXT
README
93 octetsTEXT
How to cite
Crain Danielle, Karpovich Shawna, Quakenbush Lori, Polasek Lori (2020). Using claws to compare reproduction, stress, and diet of female bearded and ringed seals in the Bering and Chukchi seas, Alaska, between 1953-1968 and 1998-2014. SEANOE. https://doi.org/10.17882/77352
In addition to properly cite this dataset, it would be appreciated that the following work(s) be cited too, when using this dataset in a publication :
Crain Danielle D, Karpovich Shawna A, Quakenbush Lori, Polasek Lori, Cooke Steven (2021). Using claws to compare reproduction, stress and diet of female bearded and ringed seals in the Bering and Chukchi seas, Alaska, between 1953–1968 and 1998–2014. Conservation Physiology, 9 (1), -. https://doi.org/10.1093/conphys/coaa115

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