Effects of acidification, lipid removal and mathematical normalization on carbon and nitrogen stable isotope compositions in beaked whale (Ziphiidae) bone

Abstract

Given the observed changes in δ(13) C values after lipid extraction, we recommend a priori lipid extraction or a posteriori lipid normalization, through simple linear models, for beaked whale bones. Furthermore, acidification seems to be an unnecessary step before stable isotope analysis, at least for bone samples of ziphiids. Copyright © 2015 John Wiley & Sons, Ltd.

Effects of skeletal element identity, delipidation and demineralization on the analysis of stable isotope ratios of C and N in fish bone

“…This is probably the consequence of demineralization, as delipidation alone has no effect on δ 15 N values of fish bone (Guiry et al ., ). Interestingly, demineralization has no effect on δ 15 N of mammal bone (Tatsch et al ., ) or dentine (Brault et al ., ; Guiry et al ., ), but has been reported to alter δ 15 N values of crustaceans and plants (Bunn et al ., ; Ng et al ., ; Mateo et al ., ).…”

“…Collagen is the main protein in bone and is highly stable at low pH at ambient temperature (Brown et al, 1988;Gage et al, 1989). Accordingly, collagen is unlikely to be affected by bone demineralization (Szpak, 2011;Guiry et al, 2016a), which could explain why demineralization does not affect the 15 N values of mammal bone (Tatsch et al, 2016) or dentine (Brault et al, 2014;Guiry et al, 2016a). Collagen, however, is not the only protein in bone; other non-collagenous proteins could be susceptible to hydrolysis at low pH and hence susceptible to loss during demineralization.…”

Fifty years of Cook Inlet beluga whale feeding ecology from isotopes in bone and teeth

“…pdf), indicating the collagen was of good quality (i.e. between 2.9 and 3.6; DeNiro et al 1985, Ambrose 1990, Tatsch et al 2016. C:N ratios from CIBW tooth dentin GLGs were between 3.1 and 5.7 ( Table S2 in the Supplement).…”

“…C:N ratios from CIBW tooth dentin GLGs were between 3.1 and 5.7 ( Table S2 in the Supplement). When a sample had a C:N ratio ≥3.6, only its δ 15 N data were used in further data analyses because C:N ratios higher than 3.6 indicate possibly compromised δ 13 C values (DeNiro et al 1985, Ambrose 1990, Tatsch et al 2016.…”

Estimating the isotopic niche of males and females of false killer whales (Pseudorca crassidens) from Magellan Strait, Chile

“…Lipids were extracted in a Soxhlet extractor with petroleum ether for 3 h, since lipid extraction does not affect significantly the δ 15 N values of cetacean tissues (Tatsch et al . , Newsome et al . ).…”