Spatial variability in responses to environmental conditions in Southern Hemisphere long-finned pilot whales

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 629:207-218 (2019) - DOI: https://doi.org/10.3354/meps13109 Spatial variability in responses to environmental conditions in Southern Hemisphere long-finned pilot whales Vicki Hamilton1,*, Karen Evans1,2, Ben Raymond1,3,4, Emma Betty5,6, Mark A. Hindell1,4 1Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania 7000, Australia 2CSIRO Oceans and Atmosphere, Hobart, Tasmania 7000, Australia 3Australian Antarctic Division, Department of the Environment and Energy, Kingston, Tasmania 7050, Australia 4Antarctic Climate and Ecosystems CRC, Hobart, Tasmania 7000, Australia 5School of Science, Faulty of Health and Environmental Sciences, Auckland University of Technology, Auckland 1142, New Zealand 6School of Natural and Computational Sciences, College of Sciences, Massey University, North Shore, Auckland 0745, New Zealand *Corresponding author: vicki.hamilton@utas.edu.au ABSTRACT: Investigating past responses to variations in the marine environment can provide insights into how species might respond to future change. Using long-finned pilot whales Globicephala melas stranded in New Zealand (2011) and Australia (2012), we investigated relationships between tooth growth chronologies, as a proxy for energy budgets (which underpin population state), and interannual variations in broad-scale climate indices (Southern Oscillation Index [SOI], Indian Ocean Dipole [IOD]) and spatially explicit, seasonally averaged sea surface temperature (SST). Tooth chronologies from pilot whales that stranded in Australia had a positive relationship with the SOI and a negative relationship with the IOD. Those from New Zealand had a positive relationship with the SOI, but at a 1 yr lag. Positive SOI and negative IOD conditions are associated with increased storm activity across the southern Australian/New Zealand region. The resulting changes in regional SST, currents and frontal activity likely influences the distribution of prey resources and associated high-order predators such as pilot whales. Correlation maps between tooth growth chronologies and SSTs suggest differences in habitat utilisation between the 2 regional groups, with pilot whales stranded in Australia associating with the subtropical and subantarctic fronts south of Tasmania, and those stranded in New Zealand associating with a number of regions of seasonally enhanced productivity close to New Zealand. This study greatly enhances our understanding of the environmental conditions influencing populations of an insufficiently studied species in the region. KEY WORDS: Energy budget · Tooth growth chronology · Globicephala melas · Indian Ocean Dipole · Southern Oscillation Index · Sea surface temperature Full text in pdf format Supplementary material PreviousNextCite this article as: Hamilton V, Evans K, Raymond B, Betty E, Hindell MA (2019) Spatial variability in responses to environmental conditions in Southern Hemisphere long-finned pilot whales. Mar Ecol Prog Ser 629:207-218. https://doi.org/10.3354/meps13109 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 629. Online publication date: October 24, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.