Accounting for the effects of lipids in stable isotope (δ 13 C and δ 15 N values) analysis of skin and blubber of balaenopterid whales
RATIONALE Stable isotope values ( δ 13 C and δ 15 N) of darted skin and blubber biopsies can shed light on habitat use and diet of cetaceans, which are otherwise difficult to study. Non‐dietary factors affect isotopic variability, chiefly the depletion of 13 C due to the presence of 12 C‐rich lipids...
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crwiley:10.1002/rcm.6394 2024-09-15T17:57:22+00:00 Accounting for the effects of lipids in stable isotope (δ 13 C and δ 15 N values) analysis of skin and blubber of balaenopterid whales Ryan, Conor McHugh, Brendan Trueman, Clive N. Harrod, Chris Berrow, Simon D. O'Connor, Ian 2012 http://dx.doi.org/10.1002/rcm.6394 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Frcm.6394 http://onlinelibrary.wiley.com/wol1/doi/10.1002/rcm.6394/fullpdf en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Rapid Communications in Mass Spectrometry volume 26, issue 23, page 2745-2754 ISSN 0951-4198 1097-0231 journal-article 2012 crwiley https://doi.org/10.1002/rcm.6394 2024-08-22T04:16:48Z RATIONALE Stable isotope values ( δ 13 C and δ 15 N) of darted skin and blubber biopsies can shed light on habitat use and diet of cetaceans, which are otherwise difficult to study. Non‐dietary factors affect isotopic variability, chiefly the depletion of 13 C due to the presence of 12 C‐rich lipids. The efficacy of post hoc lipid‐correction models (normalization) must be tested. METHODS For tissues with high natural lipid content (e.g., whale skin and blubber), chemical lipid extraction or normalization is necessary. C:N ratios, δ 13 C values and δ 15 N values were determined for duplicate control and lipid‐extracted skin and blubber of fin ( Balaenoptera physalus ), humpback ( Megaptera novaeangliae ) and minke whales ( B. acutorostrata ) by continuous‐flow elemental analysis isotope ratio mass spectrometry (CF‐EA‐IRMS). Six different normalization models were tested to correct δ 13 C values for the presence of lipids. RESULTS Following lipid extraction, significant increases in δ 13 C values were observed for both tissues in the three species. Significant increases were also found for δ 15 N values in minke whale skin and fin whale blubber. In fin whale skin, the δ 15 N values decreased, with no change observed in humpback whale skin. Non‐linear models generally out‐performed linear models and the suitability of models varied by species and tissue, indicating the need for high model specificity, even among these closely related taxa. CONCLUSIONS Given the poor predictive power of the models to estimate lipid‐free δ 13 C values, and the unpredictable changes in δ 15 N values due to lipid‐extraction, we recommend against arithmetical normalization in accounting for lipid effects on δ 13 C values for balaenopterid skin or blubber samples. Rather, we recommend that duplicate analysis of lipid‐extracted ( δ 13 C values) and non‐treated tissues ( δ 15 N values) be used. Copyright © 2012 John Wiley & Sons, Ltd. Article in Journal/Newspaper Balaenoptera physalus Fin whale Humpback Whale Megaptera novaeangliae minke whale Wiley Online Library Rapid Communications in Mass Spectrometry 26 23 2745 2754 |
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Wiley Online Library |
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English |
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RATIONALE Stable isotope values ( δ 13 C and δ 15 N) of darted skin and blubber biopsies can shed light on habitat use and diet of cetaceans, which are otherwise difficult to study. Non‐dietary factors affect isotopic variability, chiefly the depletion of 13 C due to the presence of 12 C‐rich lipids. The efficacy of post hoc lipid‐correction models (normalization) must be tested. METHODS For tissues with high natural lipid content (e.g., whale skin and blubber), chemical lipid extraction or normalization is necessary. C:N ratios, δ 13 C values and δ 15 N values were determined for duplicate control and lipid‐extracted skin and blubber of fin ( Balaenoptera physalus ), humpback ( Megaptera novaeangliae ) and minke whales ( B. acutorostrata ) by continuous‐flow elemental analysis isotope ratio mass spectrometry (CF‐EA‐IRMS). Six different normalization models were tested to correct δ 13 C values for the presence of lipids. RESULTS Following lipid extraction, significant increases in δ 13 C values were observed for both tissues in the three species. Significant increases were also found for δ 15 N values in minke whale skin and fin whale blubber. In fin whale skin, the δ 15 N values decreased, with no change observed in humpback whale skin. Non‐linear models generally out‐performed linear models and the suitability of models varied by species and tissue, indicating the need for high model specificity, even among these closely related taxa. CONCLUSIONS Given the poor predictive power of the models to estimate lipid‐free δ 13 C values, and the unpredictable changes in δ 15 N values due to lipid‐extraction, we recommend against arithmetical normalization in accounting for lipid effects on δ 13 C values for balaenopterid skin or blubber samples. Rather, we recommend that duplicate analysis of lipid‐extracted ( δ 13 C values) and non‐treated tissues ( δ 15 N values) be used. Copyright © 2012 John Wiley & Sons, Ltd. |
format |
Article in Journal/Newspaper |
author |
Ryan, Conor McHugh, Brendan Trueman, Clive N. Harrod, Chris Berrow, Simon D. O'Connor, Ian |
spellingShingle |
Ryan, Conor McHugh, Brendan Trueman, Clive N. Harrod, Chris Berrow, Simon D. O'Connor, Ian Accounting for the effects of lipids in stable isotope (δ 13 C and δ 15 N values) analysis of skin and blubber of balaenopterid whales |
author_facet |
Ryan, Conor McHugh, Brendan Trueman, Clive N. Harrod, Chris Berrow, Simon D. O'Connor, Ian |
author_sort |
Ryan, Conor |
title |
Accounting for the effects of lipids in stable isotope (δ 13 C and δ 15 N values) analysis of skin and blubber of balaenopterid whales |
title_short |
Accounting for the effects of lipids in stable isotope (δ 13 C and δ 15 N values) analysis of skin and blubber of balaenopterid whales |
title_full |
Accounting for the effects of lipids in stable isotope (δ 13 C and δ 15 N values) analysis of skin and blubber of balaenopterid whales |
title_fullStr |
Accounting for the effects of lipids in stable isotope (δ 13 C and δ 15 N values) analysis of skin and blubber of balaenopterid whales |
title_full_unstemmed |
Accounting for the effects of lipids in stable isotope (δ 13 C and δ 15 N values) analysis of skin and blubber of balaenopterid whales |
title_sort |
accounting for the effects of lipids in stable isotope (δ 13 c and δ 15 n values) analysis of skin and blubber of balaenopterid whales |
publisher |
Wiley |
publishDate |
2012 |
url |
http://dx.doi.org/10.1002/rcm.6394 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Frcm.6394 http://onlinelibrary.wiley.com/wol1/doi/10.1002/rcm.6394/fullpdf |
genre |
Balaenoptera physalus Fin whale Humpback Whale Megaptera novaeangliae minke whale |
genre_facet |
Balaenoptera physalus Fin whale Humpback Whale Megaptera novaeangliae minke whale |
op_source |
Rapid Communications in Mass Spectrometry volume 26, issue 23, page 2745-2754 ISSN 0951-4198 1097-0231 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/rcm.6394 |
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Rapid Communications in Mass Spectrometry |
container_volume |
26 |
container_issue |
23 |
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2745 |
op_container_end_page |
2754 |
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1810433516033277952 |