Ba/Ca ratios in teeth reveal habitat use patterns of dolphins

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 521:249-263 (2015) - DOI: https://doi.org/10.3354/meps11158 Ba/Ca ratios in teeth reveal habitat use patterns of dolphins S. Botta1,*, C. Albuquerque2, A. A. Hohn3, V. M. F. da Silva4, M. C. O. Santos5, C. Meirelles6, L. Barbosa7, A. P. M. Di Beneditto8, R. M. A. Ramos9, C. Bertozzi10, M. J. Cremer11, V. Franco-Trecu12, N. Miekeley13,†, E. R. Secchi1 1Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega, Instituto de Oceanografia, Universidade Federal do Rio Grande, Rio Grande RS 96203-900, Brazil 2Departamento Oceanografia e Limnologia, Universidade Federal do Rio Grande do Norte, Natal 59014-100, RN, Brazil 3National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Beaufort, NC 28516, USA 4Laboratório de Mamíferos Aquáticos, Instituto Nacional de Pesquisas da Amazônia, CP 478, Manaus, AM 69011-790, Brazil 5Departamento de Oceanografia Biológica, Instituto Oceanográfico, Universidade de São Paulo, São Paulo, SP 05508-120, Brazil 6Associação de Pesquisa e Preservação de Ecossistemas Aquáticos - AQUASIS, SESC, Caucaia, CE 61627-010, Brazil 7Organização Consciência Ambiental—ORCA, Vila Velha, ES 29101-315, Brazil 8Universidade Estadual do Norte Fluminense, CBB/LCA, Campos dos Goytacazes, RJ 28013-602, Brazil 9Everest Tecnologia em Serviços Ltda. CP 5074, Vitória, ES 29045-970, Brazil 10Projeto BioPesca, Centro Universitário Monte Serrat, Santos, SP 11015-530, Brazil 11Departamento de Ciências Biológicas, Universidade da Região de Joinville, Joinville, SC 89219-710, Brazil 12Proyecto Franciscana, Sección Etología-Facultad de Ciencias, Iguá 4225, Montevideo, CP 11400, Uruguay 13Departamento de Química, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, RJ 22453-900, Brazil *Corresponding author: silbotta@gmail.com†Deceased ABSTRACT: Teeth and otoliths are metabolically inert structures that preserve a chronology of chemical variations that may be related to the environmental histories experienced by each organism. Because of the natural decrease of barium (Ba) and increase of strontium (Sr) bioavailability in water with increasing salinity, these elements may be especially useful to track habitat use in aquatic organisms. Therefore, we tested whether the Ba/Ca and Sr/Ca ratios in the teeth of dolphins represent a salinity gradient. The main aim was to determine whether these elements can be used as a natural tag for different aquatic environments. Teeth from 2 freshwater dolphins (Inia geoffrensis and Sotalia fluviatilis) and 2 marine species (S. guianensis and Pontoporia blainvillei) from Brazil and Uruguay were analyzed using a Laser Ablation Inductively Coupled Plasma-Mass Spectrometer. Intensity ratios of 138Ba/43Ca and 86Sr/43Ca were measured along a line that covered all growth increments in the dentin from the second year of life onwards. Teeth from the freshwater species had mean Ba/Ca values tenfold higher than marine dolphins, confirming the inverse relationship between salinity (and thus ambient Ba/Ca) and elemental ratios in teeth. Furthermore, Ba/Ca ratios could also differentiate dolphins from lower-salinity estuarine areas from those in areas with minimal freshwater discharge. No significant differences were found for Sr/Ca values. Results presented encouraging indications for the application of this technique as a potential new tool for studying habitat use in aquatic mammals. KEY WORDS: Barium · Strontium · Laser ablation ICP-MS · Habitat use · Odontocetes Full text in pdf format PreviousNextCite this article as: Botta S, Albuquerque C, Hohn AA, da Silva VMF and others (2015) Ba/Ca ratios in teeth reveal habitat use patterns of dolphins. Mar Ecol Prog Ser 521:249-263. https://doi.org/10.3354/meps11158 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 521. Online publication date: February 17, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.