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Intraspecific differences in movement, dive behavior and vertical habitat preferences of a key marine apex predator
Citation
Stehfest, KM and Patterson, TA and Barnett, A and Semmens, JM, Intraspecific differences in movement, dive behavior and vertical habitat preferences of a key marine apex predator, Marine Ecology - Progress Series, 495 pp. 249-262. ISSN 0171-8630 (2014) [Refereed Article]
Copyright Statement
Copyright 2014 Inter-Research and CSIRO
Abstract
Understanding the patterns of large-scale movements of highly mobile marine
predators is essential to understanding the impacts of anthropogenic pressures on the animals and
the ecosystems they frequent. The broadnose sevengill shark Notorynchus cepedianus is one of
the most important apex predators in temperate coastal areas around the world, yet little is known
of its seasonal large-scale movements. Five male and five female sevengill sharks were equipped
with pop-up satellite archival tags (PSATs) in a coastal embayment in southern Tasmania, that collected
depth and temperature data during winter, when the animals leave the coastal embayment,
resulting in a dataset covering a total of 818 d. Animal tracks indicated that males moved northwards
into warmer waters, whereas females remained in southern waters. Three of the females
stayed in the Tasmanian coastal areas while the other two left, with one of them moving into
deeper waters of up to 360 m depth at the southern edge of the Tasmanian shelf before returning
to the Tasmanian coast. These sex-specific differences in large-scale movement could potentially
lead to the differential exploitation of the sexes when the sharks leave the protected areas where
they were tagged. Both males and females switched between diel vertical migration and reverse
diel vertical migration over the course of their tracks and displayed oscillatory vertical movements,
probably linked to foraging. These vertical movements persisted throughout the tracks,
suggesting that sevengill sharks foraged continuously during their migration rather than switching
between transiting and foraging modes.
Item Details
Item Type: | Refereed Article |
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Keywords: | broadnose sevengill shark, Notorynchus cepedianus, pop-up satellite archival tag, biotelemetry, wavelet analysis, sex-specific, hexanchiformes |
Research Division: | Biological Sciences |
Research Group: | Ecology |
Research Field: | Marine and estuarine ecology (incl. marine ichthyology) |
Objective Division: | Environmental Management |
Objective Group: | Marine systems and management |
Objective Field: | Marine biodiversity |
UTAS Author: | Stehfest, KM (Dr Kilian Stehfest) |
UTAS Author: | Barnett, A (Dr Adam Barnett) |
UTAS Author: | Semmens, JM (Professor Jayson Semmens) |
ID Code: | 88197 |
Year Published: | 2014 |
Web of Science® Times Cited: | 11 |
Deposited By: | Sustainable Marine Research Collaboration |
Deposited On: | 2014-01-17 |
Last Modified: | 2017-11-01 |
Downloads: | 0 |
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