Key biological indices required to understand and manage nesting sea turtles along the Kimberley coast KIMBERLEY NODE - WAMSI PROJECT 1.2.2 SCOTT WHITING, TONY TUCKER, NICOLA MITCHELL, OLIVER BERRY, KELLIE PENDOLEY, NANCY FITZSIMMONS, BLAIR BENTLEY
11 Indigenous Partners
Who to partner with
Scott Whiting Tony Tucker Nicki Nicola Mitchell Olly Oliver Berry Nancy Nancy FitzSimmons Kellie Pendoley Blair Bentley Jessica Stubbs
Other Acknowledgements DBCA Kununurra Office and Broome Office, Ben Corey, Leah Pearson, Craig Williams, Erina Young Northwest Shelf Flatback Turtle Conservation Program funding
Context Why Turtles? Highly valued Indigenous values cultural, food, economic, Values Iconic, accessible to people, rehabilitation Threatened Legislative responsibility (State, Commonwealth) Political value Priority for management action Flagship for conservation (saleable icon) Links between most marine habitats Links between people and sea locations Common global issues pollution, bycatch, coastal development
Scoping the project Parameters needed for management (nesting life stage) Skills of WAMSI partners and other colleagues that we could engage Indigenous engagement Budget Logistics
WAMSI Turtle Questions: 1) Distribution and Abundance What species nest on Kimberley beaches? When/where are they nesting? Integration of Western Science and Traditional Knowledge 2) Genetics How are these turtles related to other groups? What are the stocks? 3) Climate Change and Increasing Temperatures What will be the impacts of climate change? 4) Indigenous Knowledge How can we combine Traditional Knowledge and western science? Geographic Scope entire Kimberley Coast from NT border to southern end of Eighty Mile Beach
Indigenous Engagement We placed emphasis on engagement including: Early face to face meetings to discuss plans KLC - Research, Ethics, Access Committee process Individual written scopes of works with several groups Multiple dedicated planning trips to the Kimberley Budgeted - wages, engagement fees and communication products Emphasis on training
WAMSI 1.2.2 Marine Turtles Kimberley marine turtlesan inventory of distribution and abundance Tony Tucker, Kellie Pendoley, Scott Whiting
Right mix WAMSI knowledge needs on Kimberley marine turtles prompted by: (1) new Marine Parks, (2) Indigenous ranger groups in oncountry management, and (3) 2017 Marine Turtle Recovery Plans. of Image courtesy of Alana Grech, JCU Crafting a marine turtle inventory that strategically combines: long time frames (traditional knowledge) and large spatial scale (aerial surveys)
Broad aims Inventory questions are shaped by scale Where? When? How many? Remote coasts spanning 12,000 km, 2,633 islands, and 1,375 mainland beaches. 91% access by foot, boat, copter, floatplane
Aerial survey/image capture (2) Flight planning (3) Image capture Photo the sandy pixels of beaches across the Kimberley in 8 flight days for summer & winter Images: K. Pendoley Jan and Aug 2014 (44,000 images) 91% of 2,633 islands and 1,375 mainland beaches.
W-S change at the Dampier Peninsula/King Sound Summer tracks Winter tracks South North Summer Winter
Track Counts & Density Estimates track counts and density are criteria that frame management or monitoring decisions
Kimberley highest density rookeries
(5) GIS products Landscape scale Summer or Winter high priorities in Marine Parks by partnering with 11 ranger groups
High priority
Changing priorities with the seasons Summer Winter
Distilled advise Management Implications: co-management TO group Primary Rookery Nesting by Flatback/green/ olive ridley Miriuwung Gadjerrong Cape Domett (2006-2016) FB Balanggarra Lacrosse, W. Governor FB Foraging Wunambal Gaambera Maret, Montelivet, Cassini FB/GN Mary Isl. (CSIRO) Dambimangarri Camden Sound, Langgii* FB/GN, OR* Montgomery Reef Mayala Helpman FB Bardi Jawi Dampier Peninsula* OR* Sunday Isl. (CSIRO) Nyul Nyul Lacepedes (1987-2002) GN Lacepedes Yawaru Cable Beach, Ecobeach FB Roebuck Bay KariJarri Anna Plains FB Nyangumarta 80 Mile Beach (2006-2016) FB Ngarla Pardoo FB
In a nutshell Outcomes Mapped nesting distribution at landscape and local scales Base information to plan long term monitoring Rangers and TO s trained in onground techniques
Where do turtles go? follow the genes
Flatback Turtles Australian endemic vulnerable What we asked: How many genetically distinct groups of flatback turtles exist in Australia? What we did: New samples, new regions, new genomic analyses What we found: Three major groups of flatback turtles. 2 Model-based clustering analysis MCMC search for optimal number of genetically distinct, yet homogenous groups (STRUCTURE Analysis)?? Sites sampled Winter nesting Summer nesting 3
Green Turtles Global tropical distribution vulnerable What we asked: How many genetically distinct groups of green turtles exist in northern Australia? What we found: Two major groups of green turtles Also, Kimberley-Ningaloo distinct What we did: New samples, new regions, new genomic analyses 2 Model-based clustering analysis MCMC search for optimal number of genetically distinct, yet homogenous groups (STRUCTURE Analysis)?? 3 Sites analysed
Future nesting success under climate change Blair Nicki
Context 1. Variation in beach temperatures and nesting phenology (seasonality) 2. Thermal thresholds for embryos (sex and survival) 3. Impacts of climate change on sex ratios and clutch mortality
Kimberley beach temperatures Field methods for beach temperature modelling Deployment of weather stations Collection of sand samples for reflectance Ad-hoc measurement of sand temperatures Mechanistic models A Parameterised with site-specific sand reflectance and climates Three different climate inputs compared: B C Weather station (WS) Australian climate surface (AWAP) Global climate model (GCM)
Kimberley beach temperatures Conclusions from beach temperature simulations Can be modelled with reasonable accuracy Many rookeries currently too cold in winter to support nesting Difference in summer/winter sand temperatures ranges from 4-8⁰C, depending on rookery AWAP GCM WS FIELD DATA Temperature (⁰C) Date Cape Domett
Thermal physiology of embryos Methods for determining thermal sensitivities of embryos 28 C 33 C
Physiology: GREEN TURTLES West Lacepede Island Pivotal temperature 29.4 C Mixed sexes produced across a broad range of temperatures Peak development rae about 34 C FLATBACK TURTLES Eighty Mile Beach (Summer) and Cape Domett (Winter) Pivotal temperature 30.5 C and 29.5 C Mixed sexes produced across a narrower range of temperatures Peak development rate 33.4 C and 33.8 C C D
Putting it all together Linked beach temperature models with new physiological data Microclimate model Drivers Historical hourly climate data (1990-onwards) Site-specific parameters Sand properties and nest shade Climate change scenarios Nest temperatures 50 cm Customised for each species and rookery Development rate function Physiologica l model CTE during the thermosensitive period (TSP) TSD function Primary sex ratio TSP delineatio n
Rookery sex ratio: Green turtles West Lacepede Islands Current climate current nesting phenology promotes female-skewed primary sex ratios Any winter nesting would produce males West Lacepede Islands Future climates Little change by 2030 By 2070, rookeries feminised unless phenology (seasonality) shifts Embryos survive extra heat, except under the most extreme 2070 scenario
Rookery sex ratios: Flatback turtles Cape Domett (Winter) and Eighty Mile Beach (Summer) Current climate Cape Domett produces mixed sex ratios EMB Summer nesting supports females Winter nesting Summer nesting Future climate By 2030, CD barely producing males with current nesting phenology By 2070 at CD, almost all likely climates will lead to embryonic mortality Mixed sex ratios can be produced at EMB under future climates by earlier nesting in season
Risk analysis Winter nesting populations will gradually decline if no rookeries produce males Under a severe climate change scenario for 2070, few current sea turtle rookeries in the Kimberley would be viable. Southern most rookeries likely to maintain viability under future climates
WRAP UP
Communication/Outputs Meetings with managers - 20 Meetings with Indigenous managers - 44 Field Trips /Training - 32 Media (radio/print) - 20 Conference Proceedings seminars /conference presentations 28 Peer Reviewed Scientific Papers Completed 1 others expected 4 Community Field reports 4 Posters 2
Outcomes 1. Nesting distribution mapped across Kimberley at local and regional scales 2. Genetic stocks defined for flatback and greens 3. Pivotal temperatures determined and models predict climate change impact 4. Engagement and training with 11 Indigenous partners 5. Completion of regional scale project with local, regional and national scale advice and implications
This is not the end, but just the beginning!! Turtles are long lived - so the projects need to be.