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

Gredzens C, Marsh H, Fuentes MM, Limpus CJ, Shimada T, Hamann M - PLoS ONE (2014)

Bottom Line: Additionally, sympatric and inter-related species are often managed separately, which may not be cost-effective.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.

View Article: PubMed Central - PubMed

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.

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.

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Related in: MedlinePlus

Home-range and core area size of tracked dugongs and green turtles.Comparison of 95% home-ranges (left) and 50% core areas (right) between Shoalwater Bay, Australia dugongs (n = 5), green sea turtles (n = 6) and a transient dugong (n = 1) (top) with Torres Strait, Australia dugongs (n = 6), reef associated green sea turtles (n = 3), and a transient green sea turtle (n = 1) (bottom) over the total tracking time of each animal. Lines within boxes represent the median, boxes represent interquartile range, whiskers represent minimum and maximum values, and dots indicate values for each individual. Note differences in scale on y axes.
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pone-0098944-g001: Home-range and core area size of tracked dugongs and green turtles.Comparison of 95% home-ranges (left) and 50% core areas (right) between Shoalwater Bay, Australia dugongs (n = 5), green sea turtles (n = 6) and a transient dugong (n = 1) (top) with Torres Strait, Australia dugongs (n = 6), reef associated green sea turtles (n = 3), and a transient green sea turtle (n = 1) (bottom) over the total tracking time of each animal. Lines within boxes represent the median, boxes represent interquartile range, whiskers represent minimum and maximum values, and dots indicate values for each individual. Note differences in scale on y axes.

Mentions: Four of the five dugongs used relatively small ranges with 95% home-range areas ranging from 15.9 km2 to 72.8 km2 (median: 49.5 km2) and 50% core areas ranging between 2.6 km2 and 21.3 km2 (median: 4.2 km2), encompassing a total area of 123.7 km2 (95%) and 28.5 km2 (50%) (Figure 1; Table S2). The fifth individual (652636A – female) had a significantly larger range with a 95% home-range of 1444.6 km2 and 50% core area of 114.4 km2 and exhibited behavior consistent with a transient animal.


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

Gredzens C, Marsh H, Fuentes MM, Limpus CJ, Shimada T, Hamann M - PLoS ONE (2014)

Home-range and core area size of tracked dugongs and green turtles.Comparison of 95% home-ranges (left) and 50% core areas (right) between Shoalwater Bay, Australia dugongs (n = 5), green sea turtles (n = 6) and a transient dugong (n = 1) (top) with Torres Strait, Australia dugongs (n = 6), reef associated green sea turtles (n = 3), and a transient green sea turtle (n = 1) (bottom) over the total tracking time of each animal. Lines within boxes represent the median, boxes represent interquartile range, whiskers represent minimum and maximum values, and dots indicate values for each individual. Note differences in scale on y axes.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4043907&req=5

pone-0098944-g001: Home-range and core area size of tracked dugongs and green turtles.Comparison of 95% home-ranges (left) and 50% core areas (right) between Shoalwater Bay, Australia dugongs (n = 5), green sea turtles (n = 6) and a transient dugong (n = 1) (top) with Torres Strait, Australia dugongs (n = 6), reef associated green sea turtles (n = 3), and a transient green sea turtle (n = 1) (bottom) over the total tracking time of each animal. Lines within boxes represent the median, boxes represent interquartile range, whiskers represent minimum and maximum values, and dots indicate values for each individual. Note differences in scale on y axes.
Mentions: Four of the five dugongs used relatively small ranges with 95% home-range areas ranging from 15.9 km2 to 72.8 km2 (median: 49.5 km2) and 50% core areas ranging between 2.6 km2 and 21.3 km2 (median: 4.2 km2), encompassing a total area of 123.7 km2 (95%) and 28.5 km2 (50%) (Figure 1; Table S2). The fifth individual (652636A – female) had a significantly larger range with a 95% home-range of 1444.6 km2 and 50% core area of 114.4 km2 and exhibited behavior consistent with a transient animal.

Bottom Line: Additionally, sympatric and inter-related species are often managed separately, which may not be cost-effective.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.

View Article: PubMed Central - PubMed

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.

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.

Show MeSH
Related in: MedlinePlus