eCite Digital Repository
Identifying foraging habitats of adult female long-nosed fur seal Arctocephalus forsteri based on vibrissa stable isotopes
Citation
Foo, D and Hindell, M and McMahon, C and Goldsworthy, S, Identifying foraging habitats of adult female long-nosed fur seal Arctocephalus forsteri based on vibrissa stable isotopes, Marine Ecology - Progress Series, 628 pp. 223-234. ISSN 0171-8630 (2019) [Refereed Article]
 | PDF Available from 04 October 2024 598Kb |
Copyright Statement
Copyright 2019 Inter-Research
Abstract
We investigated how foraging ecotypes of female long-nosed fur seals Arctocephalus forsteri could be identified from vibrissa stable isotopes. We collected regrowths of vibrissae from adult females (n = 18) from Cape Gantheaume, Kangaroo Island, South Australia, from 2 breeding seasons (2016, 2017). The period represented by the regrowth was known, and 8 individuals were administered with 15N-enriched glycine as a biomarker to mark the start date of the regrowth. Non-glycine-marked and glycine-marked vibrissae were used to estimate the rate of the individual vibrissa regrowth. Using individual growth rates (0.18 ± 0.04 mm d-1), we reconstructed a stable isotope (δ13C and δ15N) time series for each regrowth and allocated them to corresponding at-sea locations either based on geolocation tracks (n = 14) or foraging habitat type (shelf or oceanic) based on diving data (n = 2) of the sampled seals. Mean (±SD) δ15N from vibrissa segments was higher when females foraged on the continental shelf region (16.1 ± 0.7‰, n = 29) compared to oceanic waters (15.1 ± 0.7‰, n = 106) in 2017, whereas it was similar in both regions in 2016 (shelf: 15.3 ± 0.4‰, n = 13; oceanic: 15.4 ± 0.4‰, n = 15). Based on the stable isotope signatures of vibrissa segments, model-based clustering analysis correctly classified 79.8% as originating from shelf or oceanic foraging habitats. This demonstrates the potential of using vibrissa stable isotopes for studying the foraging ecology of an important top marine predator.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | fur seal, isoscape, foraging strategies, trophic dynamics, continental shelf, oceanic, marine top predators |
| Research Division: | Earth Sciences |
| Research Group: | Oceanography |
| Research Field: | Biological Oceanography |
| Objective Division: | Environment |
| Objective Group: | Ecosystem Assessment and Management |
| Objective Field: | Ecosystem Assessment and Management of Marine Environments |
| UTAS Author: | Foo, D ( Dahlia Foo) |
| UTAS Author: | Hindell, M (Professor Mark Hindell) |
| ID Code: | 136828 |
| Year Published: | 2019 |
| Deposited By: | Ecology and Biodiversity |
| Deposited On: | 2020-01-20 |
| Last Modified: | 2020-05-25 |
| Downloads: | 0 |
Repository Staff Only: item control page