title: Satellite tracking of sympatric marine megafauna can inform the biological basis for species co-management.
abstract: BACKGROUND
  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.
  
  
  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
  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.
authors.affiliation: School of Earth and Environmental Sciences, James Cook University, Townsville, Queensland, Australia; School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia.
authors.forename: Christian
authors.initials: C
authors.lastname: Gredzens
authors.affiliation: 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.
authors.forename: Helene
authors.initials: H
authors.lastname: Marsh
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia.
authors.forename: Mariana M P B
authors.initials: MM
authors.lastname: Fuentes
authors.affiliation: Aquatic Threatened Species Unit, Queensland Department of Environment and Heritage Protection, Brisbane, Queensland, Australia.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Limpus
authors.affiliation: School of Earth and Environmental Sciences, James Cook University, Townsville, Queensland, Australia.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shimada
authors.affiliation: 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.
authors.forename: Mark
authors.initials: M
authors.lastname: Hamann
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources; D020454:Dugong / Q000502:physiology*; D040362:Geographic Information Systems; D013686:Telemetry; D014426:Turtles / Q000502:physiology