Environmental influences on tooth growth in sperm whales from southern Australia

• Published in: Journal of Experimental Marine Biology and Ecology
• Main Authors: Hamilton, VS, Evans, K, Raymond, B, Hindell, MA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Science Bv 2013
• Subjects: Biological Sciences; Ecology; Marine and Estuarine Ecology (incl. Marine Ichthyology); Austral; Sperm whale
• Online Access: https://doi.org/10.1016/j.jembe.2013.05.031; http://ecite.utas.edu.au/88964

Long time series are a necessary tool for investigating relationships between environmental variability and populationparameters in marine predators and establishing changes in these, particularly under longer-term climaticchange. Multi-decadal ecological datasets are however, generally lacking, as their collection requires substantialcommitment.We examined time series of growth layer group widths measured in sperm whale teeth, as indicatorsof energetic history, firstly to investigate commonalities in growth both within and between individuals andsecondly to investigate potential relationships between tooth growth and the marine environment. Growth layergroup estimates obtained from the teeth of 27 individual whales ranged 1452 GLGs. Time series of tooth growthwere highly variable both within and between individuals, reflecting differences in overall tooth structure withinindividuals and independence of energetic budgets among individuals. Relationships between tooth growth andbroad-scale environmental variables were unclear. Spatial relationships between sea surface temperature andtooth growth histories were identified across the austral summer and corresponded to historical foraging regionsin southern Australian waters. Our results demonstrate the potential for sperm whale teeth to provide extendedtime series of individual growth and nutritional histories. Further research is needed to understand the influenceof intrinsic and extrinsic factors on tooth growth and in association, a better understanding of the responses ofmarinemammal species to environmental variability.