Dear MARMAM community, We are pleased to announce the new publication: Hackel, N.R. and W.E. McFee. (2024). Utilization of stable isotopes in teeth to investigate pygmy sperm whales (Kogia breviceps) in the southeastern United States. Marine Mammal Science. DOI: 10.1111/mms.13194. The full text is available here: http://doi.org/10.1111/mms.13194 Abstract The pygmy sperm whale (Kogia breviceps) is currently the second-most stranded cetacean in the southeastern United States (SEUS), but information concerning their population structure is severely limited. This study used stable isotope analysis to investigate the isotopic niches and population structure of K. breviceps among three regions in the SEUS determined by the distance of the continental shelf break and a fourth region in the Gulf of Mexico. Teeth from stranded individuals were subsampled via dental drill at four separate areas on each tooth, representing four different age classes: calf, juvenile, subadult, and adult. Stable isotope ratios of carbon and nitrogen were measured in the organic component of 42 teeth, and oxygen isotope ratios were measured in the inorganic (hydroxyapatite) component of 19 teeth. No differences were found in δ13C, δ15N, or δ18O values between regions. However, differences between age classes were significant for adults and subadults for δ13C and adults and juveniles for δ15N. Differences between males and females were also significant for δ15N. Results from this study provide the first carbon and nitrogen isotope values from different age classes of pygmy sperm whales as well as the first reported oxygen isotope values for this species. Please email the authors at nmontey@gmail.com or wayne.mcfee@noaa.gov if you have any questions. Thank you. Nicole Hackel and Wayne McFee -- Wayne McFee PI -Coastal Marine Mammal Assessments Key Species and Bioinformatics Branch National Centers for Coastal Ocean Science NOAA National Ocean Service 331 Ft. Johnson Rd. Charleston, SC 29412 (843) 612-0061 Follow us on Twitter! @NOAACoastalSci <https://twitter.com/noaacoastalsci> Follow us on Facebook! @NOAACoastalSci <https://www.facebook.com/NOAACoastalSci>