Satellite tracking of sympatric marine megafauna can inform the biological basis for species co-management

Christian Gredzens; Helene Marsh; Mariana M P B Fuentes; Colin J Limpus; Takahiro Shimada; Mark Hamann

doi:10.1371/journal.pone.0098944

Satellite tracking of sympatric marine megafauna can inform the biological basis for species co-management

PLoS One. 2014 Jun 3;9(6):e98944. doi: 10.1371/journal.pone.0098944. eCollection 2014.

Authors

Christian Gredzens¹, Helene Marsh², Mariana M P B Fuentes³, Colin J Limpus⁴, Takahiro Shimada⁵, Mark Hamann²

Affiliations

¹ School of Earth and Environmental Sciences, James Cook University, Townsville, Queensland, Australia; School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia.
² School of Earth and Environmental Sciences, James Cook University, Townsville, Queensland, Australia; Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University, Townsville, Queensland, Australia.
³ ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia.
⁴ Aquatic Threatened Species Unit, Queensland Department of Environment and Heritage Protection, Brisbane, Queensland, Australia.
⁵ School of Earth and Environmental Sciences, James Cook University, Townsville, Queensland, Australia.

Abstract

Context: Systematic conservation planning is increasingly used to identify priority areas for protection in marine systems. However, ecosystem-based approaches typically use density estimates as surrogates for animal presence and spatial modeling to identify areas for protection and may not take into account daily or seasonal movements of animals. Additionally, sympatric and inter-related species are often managed separately, which may not be cost-effective. This study aims to demonstrate an evidence-based method to inform the biological basis for co-management of two sympatric species, dugongs and green sea turtles. This approach can then be used in conservation planning to delineate areas to maximize species protection.

Methodology/results: Fast-acquisition satellite telemetry was used to track eleven dugongs and ten green turtles at two geographically distinct foraging locations in Queensland, Australia to evaluate the inter- and intra-species spatial relationships and assess the efficacy of existing protection zones. Home-range analysis and bathymetric modeling were used to determine spatial use and compared with existing protection areas using GIS. Dugong and green turtle home-ranges significantly overlapped in both locations. However, both species used different core areas and differences existed between regions in depth zone use and home-range size, especially for dugongs. Both species used existing protection areas in Shoalwater Bay, but only a single tracked dugong used the existing protection area in Torres Strait.

Conclusions/significance: Fast-acquisition satellite telemetry can provide evidence-based information on individual animal movements to delineate relationships between dugongs and green turtles in regions where they co-occur. This information can be used to increase the efficacy of conservation planning and complement more broadly based survey information. These species also use similar habitats, making complimentary co-management possible, but important differences exist between locations making it essential to customize management. This methodology could be applied on a broader scale to include other sympatric and inter-related species.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Conservation of Natural Resources
Dugong / physiology*
Geographic Information Systems
Telemetry
Turtles / physiology

Grants and funding

The Torres Strait field work was funded by an Australian National Environment Research Program scholarship. The project was funded by the Australian Government's Australian Marine Mammal Centre, Marine and Tropical Science Research Facility and National Environment Research Program, the Torres Strait Regional Authority, the Great Barrier Reef Marine Park Authority, the Queensland Department of Environment and Heritage Protection, and an anonymous donor with a passion for dugongs. The identity of the donor is not considered relevant to the editors or reviewers' assessment of the validity of the work. None of the research was funded, in whole or in part, by a tobacco company. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.