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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

Torres Strait dugong and green turtle spatial use.Dugong and green sea turtle tracking and foraging home-ranges within Torres Strait, between the northern tip of Australia and Papua New Guinea using the total tracking duration of each animal. Blue features indicate dugongs and red features indicate green sea turtles. (A) Comparison of dugong and green sea turtle 50% core areas in Torres Strait. (B) Home-range of the transient turtle (95889). (C) Home-ranges of reef associated turtles (inset is a close up of Gariar Reef where two turtles were resident (70455 and 95892). (D) Example home-ranges of dugongs (left: 641058A, middle: 641054A, right: 641052A). (E) Tracking locations and migratory path of the dugong that traveled to Papua New Guinea (641055A). PZJA  =  Protected Zone Joint Authority. For maps with multiple individuals plotted, each individual's 95% home-range is delineated by hatching at a different angle. Note differences in scale for each map.
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pone-0098944-g003: Torres Strait dugong and green turtle spatial use.Dugong and green sea turtle tracking and foraging home-ranges within Torres Strait, between the northern tip of Australia and Papua New Guinea using the total tracking duration of each animal. Blue features indicate dugongs and red features indicate green sea turtles. (A) Comparison of dugong and green sea turtle 50% core areas in Torres Strait. (B) Home-range of the transient turtle (95889). (C) Home-ranges of reef associated turtles (inset is a close up of Gariar Reef where two turtles were resident (70455 and 95892). (D) Example home-ranges of dugongs (left: 641058A, middle: 641054A, right: 641052A). (E) Tracking locations and migratory path of the dugong that traveled to Papua New Guinea (641055A). PZJA  =  Protected Zone Joint Authority. For maps with multiple individuals plotted, each individual's 95% home-range is delineated by hatching at a different angle. Note differences in scale for each map.

Mentions: As in Shoalwater Bay, the movements of the Torres Strait dugongs were individualistic with multiple core areas. Most animals spent a proportion of their time at a foraging site between Mabuiag and Buru Islands known as the Yarral Gumi Maza region, which is generally over 5 meters deep (Figure 3A,D). Two animals (641052A – male and 611057A – female) made movements towards the southeast boundary of the Torres Strait Protected Zone Joint Authority (PZJA) region, one individual (641054A – male) spent the majority of its time around the Orman Reefs, another animal (641055A – male) moved north to the coast of Papua New Guinea (Figure 3E), and the remaining two dugongs (641060A – female and 641058A – female) remained within the Yarral Gumi Maza region. Only one dugong (641054A – male) ventured over the reef flat and lagoon of the Orman Reefs, but this animal spent the majority of its time away from reefs in deeper-water areas and relocated off the east coast of Moa Island on 16 October 2010 where it remained for the remainder of the time it was tracked (Figure 3D). A single dugong (641058A – female) crossed into the existing Dugong Sanctuary; however, 85% of its range was outside of the Sanctuary. One individual (641052A – male) made an exploratory loop-trip of 80 km south to the Cape York Peninsula and northern GBR over a period of two days. This individual did not enter the GBRMP.


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)

Torres Strait dugong and green turtle spatial use.Dugong and green sea turtle tracking and foraging home-ranges within Torres Strait, between the northern tip of Australia and Papua New Guinea using the total tracking duration of each animal. Blue features indicate dugongs and red features indicate green sea turtles. (A) Comparison of dugong and green sea turtle 50% core areas in Torres Strait. (B) Home-range of the transient turtle (95889). (C) Home-ranges of reef associated turtles (inset is a close up of Gariar Reef where two turtles were resident (70455 and 95892). (D) Example home-ranges of dugongs (left: 641058A, middle: 641054A, right: 641052A). (E) Tracking locations and migratory path of the dugong that traveled to Papua New Guinea (641055A). PZJA  =  Protected Zone Joint Authority. For maps with multiple individuals plotted, each individual's 95% home-range is delineated by hatching at a different angle. Note differences in scale for each map.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0098944-g003: Torres Strait dugong and green turtle spatial use.Dugong and green sea turtle tracking and foraging home-ranges within Torres Strait, between the northern tip of Australia and Papua New Guinea using the total tracking duration of each animal. Blue features indicate dugongs and red features indicate green sea turtles. (A) Comparison of dugong and green sea turtle 50% core areas in Torres Strait. (B) Home-range of the transient turtle (95889). (C) Home-ranges of reef associated turtles (inset is a close up of Gariar Reef where two turtles were resident (70455 and 95892). (D) Example home-ranges of dugongs (left: 641058A, middle: 641054A, right: 641052A). (E) Tracking locations and migratory path of the dugong that traveled to Papua New Guinea (641055A). PZJA  =  Protected Zone Joint Authority. For maps with multiple individuals plotted, each individual's 95% home-range is delineated by hatching at a different angle. Note differences in scale for each map.
Mentions: As in Shoalwater Bay, the movements of the Torres Strait dugongs were individualistic with multiple core areas. Most animals spent a proportion of their time at a foraging site between Mabuiag and Buru Islands known as the Yarral Gumi Maza region, which is generally over 5 meters deep (Figure 3A,D). Two animals (641052A – male and 611057A – female) made movements towards the southeast boundary of the Torres Strait Protected Zone Joint Authority (PZJA) region, one individual (641054A – male) spent the majority of its time around the Orman Reefs, another animal (641055A – male) moved north to the coast of Papua New Guinea (Figure 3E), and the remaining two dugongs (641060A – female and 641058A – female) remained within the Yarral Gumi Maza region. Only one dugong (641054A – male) ventured over the reef flat and lagoon of the Orman Reefs, but this animal spent the majority of its time away from reefs in deeper-water areas and relocated off the east coast of Moa Island on 16 October 2010 where it remained for the remainder of the time it was tracked (Figure 3D). A single dugong (641058A – female) crossed into the existing Dugong Sanctuary; however, 85% of its range was outside of the Sanctuary. One individual (641052A – male) made an exploratory loop-trip of 80 km south to the Cape York Peninsula and northern GBR over a period of two days. This individual did not enter the GBRMP.

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