Skip to main content
Article
Satellite Telemetry Reveals Higher Fishing Mortality Rates Than Previously Estimated, Suggesting Overfishing of an Apex Marine Predator
Proceedings of the Royal Society B: Biological Sciences
  • Michael Byrne, Nova Southeastern University
  • Enric Cortes, National Oceanic and Atmospheric Administration
  • Jeremy Vaudo, Nova Southeastern University
  • Guy Harvey, Nova Southeastern University
  • Mark Sampson, Fish Finder Adventures
  • Bradley M. Wetherbee, Nova Southeastern University; University of Rhode Island
  • Mahmood S. Shivji, Nova Southeastern University
Document Type
Article
Publication Date
8-16-2017
Keywords
  • Conservation,
  • Fisheries,
  • Isurus oxyrinchus,
  • Mortality,
  • Shortfin mako shark,
  • Stock assessment
Abstract
Overfishing is a primary cause of population declines for many shark species of conservation concern. However, means of obtaining information on fishery interactions and mortality, necessary for the development of successful conservation strategies, are often fisheries-dependent and of questionable quality for many species of commercially exploited pelagic sharks. We used satellite telemetry as a fisheries-independent tool to document fisheries interactions, and quantify fishing mortality of the highly migratory shortfin mako shark (Isurus oxyrinchus) in the western North Atlantic Ocean. Forty satellite-tagged shortfin mako sharks tracked over 3 years entered the Exclusive Economic Zones of 19 countries and were harvested in fisheries of five countries, with 30% of tagged sharks harvested. Our tagging-derived estimates of instantaneous fishing mortality rates (F = 0.19–0.56) were 10-fold higher than previous estimates from fisheries-dependent data (approx. 0.015–0.024), suggesting data used in stock assessments may considerably underestimate fishing mortality. Additionally, our estimates of F were greater than those associated with maximum sustainable yield, suggesting a state of overfishing. This information has direct application to evaluations of stock status and for effective management of populations, and thus satellite tagging studies have potential to provide more accurate estimates of fishing mortality and survival than traditional fisheries-dependent methodology.
Comments

©2017 The Author(s) Published by the Royal Society. All rights reserved.

Additional Comments
Florida Sea Grant award #: UFDSP00010205
ResearcherID
G-4080-2013
DOI
10.1098/rspb.2017.0658
Citation Information
Michael Byrne, Enric Cortes, Jeremy Vaudo, Guy Harvey, et al.. "Satellite Telemetry Reveals Higher Fishing Mortality Rates Than Previously Estimated, Suggesting Overfishing of an Apex Marine Predator" Proceedings of the Royal Society B: Biological Sciences Vol. 284 Iss. 1860 (2017) p. 1 - 8 ISSN: 0962-8452
Available at: http://works.bepress.com/mahmood-shivji/139/