Title

Oceanic Nomad or Coastal Resident? Behavioural Switching in the Shortfin Mako Shark (Isurus oxyrinchus)

Authors

Malcolm P. Francis, National Institute of Water and Atmospheric Research - New Zealand
Mahmood S. Shivji, Nova Southeastern UniversityFollow
Clinton A. J. Duffy, Department of Conservation - New Zealand
Paul J. Rogers, South Australia Research and Development Institute - Australia
Michael Byrne, University of Missouri
Bradley M. Wetherbee, Nova Southeastern University; University of Rhode IslandFollow
Scott C. Tindale, Tindale Marine Research Charitable Trust - New Zealand
Warrick S. Lyon, National Institute of Water and Atmospheric Research - New Zealand
Megan M. Meyers, The University of Auckland - New Zealand

Document Type

Article

Publication Date

1-2019

Publication Title

Marine Biology

ISSN

0025-3162

Volume

1

First Page

Article 5; 1

Last Page

16

Abstract

Pelagic sharks are vulnerable to overfishing because of their low reproductive rates, generally low growth rates, and high catch rates in tuna and billfish fisheries worldwide. Pelagic sharks often migrate long distances, but they may also occur close to shore, making it difficult to classify their behaviour on the continuum from oceanic nomad to coastal resident. This has important implications for fishery management, which must be targeted at an appropriate spatial scale. Conventional tagging indicates that shortfin mako sharks move widely around the southwest Pacific Ocean, but there is little information on their habitat use or mobility in the region. This study deployed electronic tags on 14 mostly juvenile New Zealand mako sharks to investigate their habitat use, and the spatial and temporal scale of their movements. Movement behaviour was classified as Resident or Travel, with the former focused in New Zealand coastal waters, and the latter in oceanic waters around New Zealand and along oceanic ridges running north towards the tropical islands of Fiji, Vanuatu and New Caledonia. Sharks regularly switched between Resident and Travel behavioural states, but their residency periods sometimes lasted for several months. Sharks spent most of their time in the New Zealand Exclusive Economic Zone (median 77%, five sharks > 90%), presumably because of the high coastal productivity and access to abundant prey. These results challenge the conventional view that mako sharks are nomadic wanderers, and suggest that fishing mortality should be managed at a local as well as a regional scale.

Comments

©Springer-Verlag GmbH Germany, part of Springer Nature 2018

NSUWorks Citation

Francis, Malcolm P.; Mahmood S. Shivji; Clinton A. J. Duffy; Paul J. Rogers; Michael Byrne; Bradley M. Wetherbee; Scott C. Tindale; Warrick S. Lyon; and Megan M. Meyers. 2019. "Oceanic Nomad or Coastal Resident? Behavioural Switching in the Shortfin Mako Shark (Isurus oxyrinchus)." Marine Biology 1, (): Article 5; 1-16. doi:10.1007/s00227-018-3453-5.

ORCID ID

0000-0002-3753-8950

ResearcherID

G-4080-2013

DOI

10.1007/s00227-018-3453-5