Establishing the limitations on using archived marine mammal samples for stable isotope analysis: an examination of differing preservation methods on tissues of harbor porpoise ( Phocoena phocoena ) and gray seal ( Halichoerus grypus )

Moore, Daniel M.; Cunningham, Emily G.; Crowder, Kayla D.; Gröcke, Darren R.

Abstract

The use of biological samples from museum and/or archive collections is common in stable isotope research, particularly for marine mammals. Yet, the temporal stability of isotopic values across various tissue types and the influence of different preservatives on these values are not fully understood, posing significant challenges for accurate data interpretation. Here we examine the impact of three different tissue preservation methods (DMSO, ethanol, freezing), on seven different tissues (blubber, heart, kidney, lung, liver, muscle, and skin) from both a harbor porpoise (Phocoena phocoena) and a gray seal (Halichoerus grypus) for stable isotope analysis in a 1‐year period. Our results demonstrate that storage in DMSO generates greater temporal variability in δ13C and δ15N for all tissue types, particularly in the first six months of storage. Furthermore, tissues stored in DMSO often exhibited lower δ13C and δ15N values compared to those stored frozen or in ethanol. This finding highlights a significant issue for studies utilizing tissues stored in DMSO, regardless of the storage duration. These results underscore the critical need for careful consideration of preservation methods in studies involving stored tissues, providing valuable insights for experimental design and management of tissue archives.

Citation

Moore, D. M., Cunningham, E. G., Crowder, K. D., & Gröcke, D. R. (online). Establishing the limitations on using archived marine mammal samples for stable isotope analysis: an examination of differing preservation methods on tissues of harbor porpoise ( Phocoena phocoena ) and gray seal ( Halichoerus grypus ). Marine Mammal Science, Article e13168. https://doi.org/10.1111/mms.13168

• Journal Article Type: Article
• Acceptance Date: Jul 29, 2024
• Online Publication Date: Aug 14, 2024
• Deposit Date: Aug 21, 2024
• Publicly Available Date: Aug 21, 2024
• Journal: Marine Mammal Science
• Print ISSN: 0824-0469
• Electronic ISSN: 1748-7692
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Article Number: e13168
• DOI: https://doi.org/10.1111/mms.13168
• Keywords: DMSO, stable isotopes, tissue preservation, archive, ethanol, marine mammal
• Public URL: https://durham-repository.worktribe.com/output/2761034