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Linking at-sea mortality of a pelagic shearwater to breeding colonies of origin using biogeochemical markers


Lavers, JL and Bond, AL and Van Wilgenburg, SL and Hobson, KA, Linking at-sea mortality of a pelagic shearwater to breeding colonies of origin using biogeochemical markers, Marine Ecology - Progress Series, 491 pp. 265-275. ISSN 0171-8630 (2013) [Refereed Article]

Copyright Statement

Copyright 2013 Inter-Research

DOI: doi:10.3354/meps10487


An emerging issue in seabird conservation is the ability to link at-sea mortality with observed demographic changes at breeding colonies. Applications of modelling and biochemical markers can be used to assign mortalities of unknown provenance to a colony of origin ensuring conservation actions are targeted at those colonies identified as the most affected. We analysed feathers (n = 120) from flesh-footed shearwater Puffinus carneipes collected from 5 breeding colonies throughout their range. Using stable isotopes (δ15N and δ13C) and trace element concentrations (Mn, Ni, Cu, Mo, Ag, Ba, Pb), we assigned birds recovered from fishing vessels off Australia, New Zealand, and the North Pacific to colony of origin, and investigated the rate of correct assignment at 3 spatial scales. Using quadratic discriminant analysis, samples of known origin were correctly assigned to basin, region, and breeding colonies at similar rates (92.3, 81.3, and 88.1%, respectively). Stable isotopes succeeded in assigning individuals among basins (72.8%), performing less well at the region and colony level (52.5 and 36.4%, respectively). In contrast, correct assignment was consistent at all 3 scales using only trace elements (93.2, 95.7, and 96.6%, respectively). Applying our final model based on trace elements to 116 flesh-footed shearwaters taken as bycatch in eastern Australia (n = 30), Western Australia (n = 32), New Zealand (n = 16), eastern North Pacific (n = 27) and western North Pacific (n = 11), we assigned individuals to colonies in New Zealand (35.3%), Western/South Australia (36.2%), Western Australia (27.6%), and Lord Howe Island (0.9%). Bycatch in fisheries may help explain ongoing declines in fleshfooted shearwater populations across the species’ range, highlighting the utility of assignment tools to account for unobservable mortality of wildlife at-sea.

Item Details

Item Type:Refereed Article
Keywords:seabird, bycatch
Research Division:Environmental Sciences
Research Group:Environmental management
Research Field:Conservation and biodiversity
Objective Division:Environmental Management
Objective Group:Marine systems and management
Objective Field:Marine biodiversity
UTAS Author:Lavers, JL (Dr Jennifer Lavers)
ID Code:86621
Year Published:2013
Web of Science® Times Cited:8
Deposited By:IMAS Research and Education Centre
Deposited On:2013-10-03
Last Modified:2018-03-28

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