Spot turtle mating pairs from the airProject lifecycle
What? To identify and map mating areas of North West Shelf flatback turtles using aerial survey and aerial imagery and characterise the habitat.
Why? No mating or courtship areas have been identified in Western Australian waters. Unlike other species where mating is often observed close to the nesting beach, no records of regular flatback mating locations exist.
What have we found? An aerial survey around Thevenard Island and along the coast near Onslow was run in October and November 2017 to spot flatback turtle mating pairs. One mating pair was spotted during the survey. Another mating pair was spotted from land in the waters of Thevenard island. The images collected during the surveys are currently being analysed
Who are our partners? DBCA
Counting turtle tracks from above
What? We performed an aerial survey of marine turtle rookeries in the Pilbara region of Western Australia in November/December 2016. All sandy beaches of islands and mainland from Cape Keraudren westward including Tent Island in the Exmouth Gulf were surveyed in order to determine the number of turtle tracks of each species along this section of the Pilbara coastline.
Why? This project fulfills two goals of the NWSFTCP's Strategic Conservation Plan: to produce an inventory of turtle nesting locations and seasonality (spatial and temporal distribution) and to test new research methodologies, including aerial survey, that will improve monitoring efficiency.
What have we found? This aerial survey revealed that flatback turtles nest on the majority of the Pilbara islands, including some islands in the Exmouth Gulf. A map of presence and absence of turtle activity has been produced in addition to a map of turtle track density.
Who are our partners? DBCA
State-wide study of sand temperatures for monitoring future turtle nesting habitatProject lifecycle
What? To monitor sand temperatures on key beaches throughout the North West Shelf to document current thermal characteristics of nests and nesting habitats.
Why? Global temperature increases have been identified in the NWSFTCP Strategic Conservation Plan as a moderate pressure for the NWS flatback turtle management unit. Increasing temperatures are likely to lead to reduced hatching success, altered sex ratios and changes in spatial and temporal distribution of nesting and changes to foraging habitat. We need to estimate baseline condition levels in terms of sand temperature at nesting aggregations within the NWS flatback turtle management unit.
What have we found? Temperature loggers have been deployed across the state from Walpole to Cape Domett. Data from the first year of deployment have been downloaded and are currently analysed.
Who are our partners? DBCA, local ranger groups, DBCA regional offices
You are what you eat: Can a combination of skeletochronology and stable isotope reveal what flatback turtles eat and where they forage?Project lifecycle
What? Skeletochronology will generate age estimates from museum specimens, and new found carcasses for the flatback turtle, the Australian endemic which has an unknown life history stage. Stable analysis will generate chemical signatures for what flatback turtles feed upon, where they feed, and how that changes through the different life history stages.
Why? Skeletochronology will define the first ages of reproduction, growth curves, and longevity estimates for flatback turtles. Stable Isotope analysis will evaluate if and how diets change with growth from hatchling-juvenile-adult status.
What have we found? Samples of flatback turtle arm bones (the humerus) have been collected from carcasses and exported under CITES permits over 2015-2018. Samples are processed and consensus reads for age estimates are being calibrated. Isotope studies are pending. Results are expected for presentation at ISTS 2019
Who are our partners? National Marine Fisheries Service, UWA, Isotopes, CSIRO, National Fisheries Service
Specimens provided by: DBCA regional offices, Dr. Colin Limpus (QLD Department of Environmental Heritage and Protection), Dr. Mick Guinea (Charles Darwin University), Dr. Kellie Pendoley (Pendoley Environmental), Queensland Museum, NT Museum, WA Museum.
Predicting the impact of climate change on turtles in the Kimberley.Project lifecycle
What? To investigate population-specific pivotal temperatures in flatback and green turtles and in particular investigate differences between summer and winter nesters. In addition, the thermal maxima (highest temperature they can survive) of developing embryos will be estimated to determine the limits of populations within both species. Mechanistic models will be produced using NicheMapR to allow high resolution and accurate predictions of sex ratios and the mortality of embryos.
Why? Global warming is a key pressure on sea turtles and is predicted to cause feminisation of rookeries and increased embyronic mortality. The ability to predict climate change impacts on rookeries and stocks is essential for managers to understand changes and potentially implement management actions to increase the resilience of turtles.
What have we found? PhD Graduate Blair Bentley documented the pivotal temperatures (the nest temperature which produces 50% male and 50% female hatchlings) of green and flatback turtles across western Australia and found differences amongst some stocks. Predictive climate change impact modelling revealed that stocks such as winter nesting flatback turtles may be at more risk at than summer nesting turtles because they can not shift nesting to cooler seasons.
Who are our partners? WAMSI, DBCA, University of Western Australia, CSIRO