Dear Colleagues,
On behalf of my co-authors, I am pleased to announce the recent publication of the following paper in Marine Ecology Progress Series:
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
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.
Best regards,
Dr Vicki Hamilton
Adjunct Researcher
Institute for Marine and Antarctic Studies (IMAS)
University of Tasmania
Mail: IMAS/UTAS, Private Bag 129, Hobart TAS Australia 7000
T +61 3 6226 6379 | M 0408 127 092