Influence of climate oscillations on dentinal deposition in teeth of Commerson's dolphin

Authors

  • Natalia A. Dellabianca,

    Corresponding author
    1. Museo Acatushún de Aves y Mamíferos Marinos Australes (AMMA), Ushuaia, Tierra del Fuego, Argentina
    • Centro Austral de Investigaciones Científicas (CADIC), Ushuaia, Tierra del Fuego, Argentina
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  • Aleta A. Hohn,

    1. NMFS-SEFSC- NOAA Beaufort Lab, Beaufort, NC, USA
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  • R. Natalie P. Goodall,

    1. Centro Austral de Investigaciones Científicas (CADIC), Ushuaia, Tierra del Fuego, Argentina
    2. Museo Acatushún de Aves y Mamíferos Marinos Australes (AMMA), Ushuaia, Tierra del Fuego, Argentina
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  • Jorge L. Pousa,

    1. Laboratorio de Oceanografía Costera, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata, Argentina
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  • Colin D. MacLeod,

    1. Institute of Biological and Environmental Sciences (IBES), University of Aberdeen, Aberdeen, UK
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  • Mauricio Lima

    1. Centro de Estudios Avanzados en Ecología y Biodiversidad (CASEB), Pontificia Universidad Católica de Chile, Santiago, Chile
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Correspondence: Natalia A. Dellabianca, tel. + 54 2901 422 320 ext. 128, fax + 54 2901 430 644, e-mail: ndellabianc@gmail.com

Abstract

Effects of climatic oscillations on populations in marine environments are produced mainly through the lower trophic levels. Marine mammals, as top predators, are affected indirectly by these fluctuations, showing variations in their survival, growth and reproduction. The main objective of this study was to determine whether we could detect the effect of climatic oscillations on Commerson's dolphins (Cephalorhynchus c. commersonii) off Tierra del Fuego, Argentina, by examining the presence and proportion of anomalous dentinal growth layer groups (GLGs). The relative deposition of anomalous GLGs was determined using calendar years from 1960 to 2005, and related to the Southern Annular Mode (SAM) and El Niño Southern Oscillation (ENSO) events, and to mean annual sea surface temperatures (SST). Then, growth parameters between animals that did and did not show anomalous dentinal growth layer patterns in one or more of their GLGs were compared. The presence of anomalous GLGs was related to the SAM, increasing in frequency with negative values of the SAM. No relationship was found among anomalous GLGs, ENSO, and SST. There were no significant differences in growth parameters between animals with and without anomalous GLGs. Using recording structures such as teeth provided a unique way of reconstructing time series to evaluate the effects of these climatic patterns on a top predator species in an area where no similar studies have been conducted, primarily due to a lack of suitable long-term data sets.

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