Title

Refuges and Risks: Evaluating the Benefits of an Expanded MPA Network for Mobile Apex Predators

Authors

Ryan Daly, Port Elizabeth Museum at Bayworld - South Africa; Save Our Seas Foundation - Geneva, Switzerland
Malcolm J. Smale, Port Elizabeth Museum at Bayworld - South Africa; Nelson Mandela Metropolitan University - Port Elizabeth, South Africa
Sarika Singh, Deparment of Environmental Affairs - Cape Town, South Africa
Mahmood S. Shivji, Nova Southeastern UniversityFollow
Clare A. K. Daly, Save Our Seas Foundation - Geneva, Switzerland
James S. E. Lea, University of Oxford - Tubney, United Kingdom; Marine Research Facility - Jeddah, Saudi Arabia
Lara L. Sousa, University of Oxford - Tubney, United Kingdom
Bradley M. Wetherbee, Nova Southeastern University; University of Rhode IslandFollow
Richard Fitzpatrick, James Cook University - Cairns, Australia
Christopher R. Clarke, Marine Research Facility - Jeddah, Saudi Arabia
Marcus Sheaves, James Cook University - Cairns, Australia
Adam Barnett, James Cook University - Cairns, Australia

Document Type

Article

Publication Date

4-25-2018

Publication Title

Diversity and Distributions

Keywords

Conservation, Marine protected area, Satellite telemetry, Sharks, Top predators

ISSN

1366-9516

First Page

1

Last Page

14

Abstract

Aim: Concurrently, assessing the effectiveness of marine protected areas and evaluating the degree of risk from humans to key species provide valuable information that can be integrated into conservation management planning. Tiger sharks (Galeocerdo cuvier) are a wide‐ranging ecologically important species subject to various threats. The aim of this study was to identify “hotspots” of tiger shark habitat use in relation to protected areas and potential risks from fishing. Location

Location: Southwest Indian Ocean, east coast of South Africa and Mozambique.

Methods: Satellite tags were fitted to 26 tiger sharks. A subset of 19 sharks with an average period at liberty of 197 (SD = 110) days were analysed using hotspot analysis to identify areas of core habitat use. The spatial and temporal overlap of significant hotspots with current and planned marine protected areas as well as risks from fishing and culling was then calculated.

Results: There was a 5.97% spatial overlap between tiger shark hotspots and marine protected areas, which would increase significantly (p < .05) to 24.36% with the expansion of planned protected areas in South Africa and could be as high as 41.43% if Mozambique similarly expanded neighbouring protected area boundaries. Tiger sharks remained largely coastal, but only showed a spatial overlap of 5.12% with shark culling nets in South Africa. Only three sharks undertook open ocean migrations during which they were more likely to interact with longline fisheries in the region.

Main conclusions: This study demonstrates how spatial information can be used to assess the overlap between marine protected areas and the core habitats of top marine predators and highlights how congruent transnational conservation management can improve the effectiveness of protected areas. Core habitat use of marine apex predators may also be indicative of productive habitats, and therefore, predators such as tiger sharks could act as surrogate species for identifying key habitats to prioritize for conservation planning.

Comments

©2018 John Wiley & Sons Ltd

NSUWorks Citation

Daly, Ryan; Malcolm J. Smale; Sarika Singh; Mahmood S. Shivji; Clare A. K. Daly; James S. E. Lea; Lara L. Sousa; Bradley M. Wetherbee; Richard Fitzpatrick; Christopher R. Clarke; Marcus Sheaves; and Adam Barnett. 2018. "Refuges and Risks: Evaluating the Benefits of an Expanded MPA Network for Mobile Apex Predators." Diversity and Distributions , (): 1-14. doi:10.1111/ddi.12758.

ORCID ID

0000-0002-3753-8950

ResearcherID

G-4080-2013

DOI

10.1111/ddi.12758