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Markov models and network analysis reveal sex-specific differences in the space-use of a coastal apex predator

Citation

Stehfest, KM and Patterson, TA and Barnett, A and Semmens, JM, Markov models and network analysis reveal sex-specific differences in the space-use of a coastal apex predator, Oikos, 124, (3) pp. 307-318. ISSN 0030-1299 (2015) [Refereed Article]

Copyright Statement

Copyright 2014 University of Tasmania, CSIRO

DOI: doi:10.1111/oik.01429

Abstract

Understanding the links between external variables such as habitat and interactions with conspecifics and animal space-use is fundamental to developing effective management measures. In the marine realm, automated acoustic tracking has become a widely used method for monitoring the movement of free-ranging animals, yet researchers generally lack robust methods for analysing the resulting spatial-usage data.

In this study, acoustic tracking data from male and female broadnose sevengill sharks Notorynchus cepedianus, collected in a system of coastal embayments in southeast Tasmania were analyzed to examine sex-specific differences in the sharks’ coastal space-use and test novel methods for the analysis of acoustic telemetry data.

Sex-specific space-use of the broadnose sevengill shark from acoustic telemetry data was analysed in two ways: The recently proposed spatial network analysis of between-receiver movements was employed to identify sex-specific space-use patterns. To include the full breadth of temporal information held in the data, movements between receivers were furthermore considered as transitions between states of a Markov chain, with the resulting transition probability matrix allowing the ranking of the relative importance of different parts of the study area.

Both spatial network and Markov chain analysis revealed sex-specific preferences of different sites within the study area. The identification of priority areas differed for the methods, due to the fact that in contrast to network analysis, our Markov chain approach preserves the chronological sequence of detections and accounts for both residency periods and movements.

In addition to adding to our knowledge of the ecology of a globally distributed apex predator, this study presents a promising new step towards condensing the vast amounts of information collected with acoustic tracking technology into straightforward results which are directly applicable to the management and conservation of any species that meet the assumptions of our model.

Item Details

Item Type:Refereed Article
Keywords:sevengill shark, Notorynchus cepedianus, sex-specific, space use, Markov chain analysis, network analysis, shark refuge area
Research Division:Agricultural and Veterinary Sciences
Research Group:Fisheries Sciences
Research Field:Aquatic Ecosystem Studies and Stock Assessment
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - Wild Caught
Objective Field:Wild Caught Fin Fish (excl. Tuna)
Author:Stehfest, KM (Dr Kilian Stehfest)
Author:Semmens, JM (Associate Professor Jayson Semmens)
ID Code:101191
Year Published:2015
Web of Science® Times Cited:5
Deposited By:IMAS Research and Education Centre
Deposited On:2015-06-11
Last Modified:2016-04-18
Downloads:0

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