Aquatic Threatened Species Unit

Box Hill South, Australia

Aquatic Threatened Species Unit

Box Hill South, Australia
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Todd E.V.,James Cook University | Blair D.,James Cook University | Farley S.,University of Canberra | Farrington L.,University of Canberra | And 4 more authors.
Zoological Journal of the Linnean Society | Year: 2013

Effective spatial classification of freshwater biodiversity remains a worldwide conservation challenge. The isolating nature of catchment boundaries over evolutionary timescales makes them potentially important in defining natural units for biodiversity management. We sought to clarify biogeographical relationships amongst drainages within Australia's biodiverse mid-eastern coastal region (Fitzroy, Burnett, and Mary Catchments) where freshwater communities face considerable urban pressure, using a locally endemic riverine specialist, the white-throated snapping turtle, Elseya albagula. Mitochondrial and nuclear microsatellite data sets were employed to investigate past and present influences on population connectivity and to identify units for management. Populations within catchments were largely well connected genetically. However, the Fitzroy Catchment contained a distinct genetic lineage, deeply divergent from a second lineage present across the Burnett and Mary Catchments. The two lineages can be considered evolutionarily significant units that reflect historical isolation of the Fitzroy and recent coalescence of the Burnett-Mary Catchments during lowered Pleistocene sea levels. Congruence with geological evidence and patterns reported for fish and macroinvertebrates supports a shared biogeographical history of a diverse regional biota. This work highlights the need for better spatial classification of freshwater biodiversity at local as well as regional scales, including recognition of potentially cryptic diversity amongst individual river drainages. © 2013 The Linnean Society of London.

Read T.C.,Laboratory of Marine Biology and Ecology | Read T.C.,Griffith University | Fitzsimmons N.N.,Griffith University | Wantiez L.,University of New Caledonia | And 9 more authors.
Wildlife Research | Year: 2015

Context Migratory species are known to pose a challenge for conservation because it is essential to understand their complex life history in order to implement efficient conservation actions. Aims In New Caledonia, large seagrass habitats in the Grand Lagon Sud (GLS) are home to resident green turtles (Chelonia mydas) of unknown origins. To assess the stock composition in the GLS, 164 foraging turtles were sampled for genetic analysis of ∼770 base pairs of the mitochondrial DNA (mtDNA) control region. Methods Foraging turtles ranging in size from 48.0 to 108.4cm curved carapace length were captured at five different sites within the GLS between September 2012 and December 2013. To provide baseline data for mixed stock analysis, published data from rookeries were used in addition to 105 samples collected at rookeries in the d'Entrecasteaux Islands and Chesterfield Islands in New Caledonia and at Malekula Island in Vanuatu. Exact tests of population differentiation and pairwise FST estimates were used to test for differences in mtDNA haplotype frequencies. Key results These analyses indicated that rookeries in the d'Entrecasteaux Islands and Vanuatu form unique management units and that the Chesterfield Islands rookeries are linked to the Coral Sea management unit. Mixed stock analysis indicated the highest proportion (mean≤0.63) of foraging turtles originate from the d'Entrecasteaux stock. Conclusions The larger contribution is estimated to be from a large rookery from New Caledonia, but smaller contributions are suggested from other rookeries in the South Pacific. Implications Marine conservation policies in New Caledonia need to consider the links between the foraging and nesting populations of C. mydas in New Caledonia and other rookeries and foraging grounds in the Coral Sea. Journal compilation © CSIRO 2015.

Wood A.,University of Queensland | Wood A.,James Cook University | Booth D.T.,University of Queensland | Limpus C.J.,Aquatic Threatened Species Unit
Journal of Experimental Marine Biology and Ecology | Year: 2014

Sea turtle incubation biology is tightly linked to nest thermal conditions due to the effect temperature has on hatching success, sex determination, morphology and locomotion performance. Because of this relationship between nest temperature and hatchling outcomes, global warming presents an immediate threat to many sea turtle nesting beaches throughout the world. Even small rises in nest temperatures may skew sex ratios and, raise egg mortality and influence hatchling phenotypes adversely, impacting on hatchling recruitment and ultimately species survival at some rookeries. The development of adaptive management practices capable of minimizing the effects of increasing global temperature on nest temperatures is thus a priority for animals exhibiting temperature-dependent sex-determination, such as sea turtles. Here, the relationship between solar radiation exposure and nest temperatures at the Mon Repos turtle rookery, south east Queensland, Australia was explored and the relationship between nest temperature and hatchling attributes examined. Shading decreased nest temperature, and higher nest temperatures were associated with smaller sized hatchlings that had decreased locomotion performance. The use of shading to minimize nest temperature is a management strategy that may be used to mitigate detrimental effects of increased global temperatures at some rookeries. Here, we explored the viability of natural shading options, such as the planting of trees behind nesting beaches, for combating the adverse effect of increased nest temperature caused by increased air temperatures.© 2013 Elsevier B.V.

Todd E.V.,James Cook University | Blair D.,James Cook University | Limpus C.J.,Aquatic Threatened Species Unit | Limpus D.J.,Aquatic Threatened Species Unit | Jerry D.R.,James Cook University
Australian Journal of Zoology | Year: 2012

Genetic parentage studies can provide detailed insights into the mating system dynamics of wild populations, including the prevalence and patterns of multiple paternity. Multiple paternity is assumed to be common among turtles, though its prevalence varies widely between species and populations. Several important groups remain to be investigated, including the family Chelidae, which dominate the freshwater turtle fauna of the Southern Hemisphere. We used seven polymorphic microsatellite markers to investigate the presence of multiple fathers within clutches from the white-throated snapping turtle (Elseya albagula), an Australian species of conservation concern. We uncovered a high incidence of multiple paternity, with 83% of clutches showing evidence of multiple fathers and up to three males contributing to single clutches. We confirm a largely promiscuous mating system for this species in the Burnett River, Queensland, although a lone incidence of single paternity indicates it is not the only strategy employed. These data provide the first example of multiple paternity in the Chelidae and extend our knowledge of the taxonomic breadth of multiple paternity in turtles of the Southern Hemisphere. © 2012 CSIRO.

Zeh D.R.,Australian Institute of Marine Science | Zeh D.R.,James Cook University | Heupel M.R.,Australian Institute of Marine Science | Heupel M.R.,James Cook University | And 9 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2015

Marine animals face increased pressure through expanded shipping and recreational activities. Effective conservation and management of large species like marine mammals or sea turtles depend on knowledge of movement and habitat use. Previous studies have used data collected from either satellite or acoustic telemetry but rarely both. In this study, data from satellite and acoustic technologies were used to: determine the efficacy of satellite and acoustic telemetry to define dugong movement patterns; compare the benefits and limitations of each approach; examine the costs of each approach in relation to the amount and type of data provided; and relate telemetry data to the boundaries of a Go Slow area designed to protect dugongs and turtles from vessel strike within an urbanised coastal embayment (Moreton Bay, Queensland, Australia). Twenty-one dugongs were captured in seagrass habitats on the Eastern Banks of Moreton Bay in July-September 2012 and July 2013 and fitted with GPS and acoustic transmitters. Both satellite and acoustic telemetry produced reliable presence and movement data for individual dugongs. When the dugongs were within the range of the acoustic array, there was relatively good correspondence between the overall space use measures derived from GPS and acoustic transmitters, demonstrating that acoustic tracking is a potentially valuable and cost-effective tool for monitoring local dugong habitat use in environments equipped with acoustic receiver arrays. Acoustic technology may be particularly useful for species that establish home ranges with stable residency especially near large urban or port environs. However, the relative merits of the two technologies depend on the research question in the context of the species of interest, the location of the study and whether the study site has an established acoustic array. © 2014 Elsevier B.V.

Zeh D.R.,Australian Institute of Marine Science | Zeh D.R.,James Cook University | Heupel M.R.,Australian Institute of Marine Science | Heupel M.R.,James Cook University | And 4 more authors.
Endangered Species Research | Year: 2016

Incidental capture in fishing gear is the most serious threat to the survival of many species of marine mammals. Fisheries closures developed to protect marine mammals have tended to concentrate on areas of high marine mammal density. Movement corridors have generally been less protected because they are often unknown and difficult to detect. Seagrass meadows in Moreton and Hervey Bays in south-eastern Queensland support significant populations of dugongs Dugong dugon. Pedigree analysis based on genetic and ancillary biological data indicates that there is substantial movement of dugongs between these bays, which are separated by open surf coasts where dugongs are occasionally caught in inshore shark nets set for the protection of bathers. This bycatch suggests that the dugong movement corridor between Moreton and Hervey Bays is close to the coast, a hypothesis not confirmed by nearly 30 yr of dugong satellite tracking using platform transmitter terminal (PTT) technology. Twenty-nine dugongs were captured in seagrass habitats on the eastern banks of Moreton Bay in 2012-2014 and were fitted with Quick Fix GPS and acoustic transmitters. One animal was captured and tracked twice. Four dugongs were tracked moving from Moreton Bay to Hervey Bay covering distances of 278-338 km over 5-9 d; 1 dugong made the return journey. Three of the 4 animals travelled along and very close to the coast; the exact track of the fourth animal is uncertain. These results suggest that dugongs would benefit from netting closures that extend beyond seagrass meadows. © The authors 2016.

Gredzens C.,James Cook University | Marsh H.,James Cook University | Fuentes M.M.P.B.,James Cook University | Limpus C.J.,Aquatic Threatened Species Unit | And 2 more authors.
PLoS ONE | Year: 2014

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 homeranges 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. © 2014 Gredzens et al.

Read T.,University of Queensland | Read T.,Griffith University | Booth D.T.,University of Queensland | Limpus C.J.,Aquatic Threatened Species Unit
Australian Journal of Zoology | Year: 2012

La Roche Percée, in New Caledonia, is the most important loggerhead turtle rookery outside of Australia for the eastern Pacific genetic stock. The females nesting on this beach are genetically similar to the females found at the Mon Repos rookery in Queensland, Australia. This study shows how nest temperature affects the phenotype of genetically similar populations. During the 2010-11 breeding season, mean nest temperatures were significantly higher at La Roche Percée (31.8°C) than at Mon Repos (29.5°C) and the mean for the three-days-in-a-row maximum nest temperatures was also significantly higher at La Roche Percée (34.6°C), than at Mon Repos (31.7°C). Differences were found in mean hatching success (La Roche Percée 83±3%, Mon Repos 96±2%) and emergence success (La Roche Percée 76±3%, Mon Repos 93±3%). Hatchlings from La Roche Percée also had significantly lower fitness characteristics, having smaller carapace size (La Roche Percée 1565±7mm2, Mon Repos 1634±5mm2), slower self-righting times (La Roche Percée 4.7±0.1s, Mon Repos 2.7±0.1s) and slower crawling speed in terms of both absolute speed and body lengths per second (La Roche Percée 2.5±0.2cm s-1 or 0.57±0.05 body lengths s-1, Mon Repos 4.6±0.1cm s-1 or 1.04±0.02 body lengths s-1). Nest temperatures at La Roche Percée approached the upper limit of embryo thermal tolerance towards the end of incubation (34°C) and this condition may contribute to the lower hatching and emergence success and lower fitness characteristics of hatchlings at the La Roche Percée rookery. © 2012 CSIRO.

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