Energetics of Ningaloo Green Turtles Jessica Stubbs, Nicki Mitchell, Mat Vanderklift, Sabrina Fossette-Halot, Richard Pillans, Nina Marn, and Starrlight Augustine Ningaloo Outlook A partnership between BHP and CSIRO WESTERN COASTAL/OCEAN & ATMOSPHERE Ningaloo Outlook is a BHP-CSIRO Industry-Science Marine Research Partnership investing A$5.4 million over five years to gather new knowledge on the Ningaloo reef and its important ecological values
Green turtles at Ningaloo Form part of globally significant population Most research and monitoring focussed on nesting environment Foraging ecology and energetics of Ningaloo population Response to changing conditions Dynamic Energy Budget model 2
Project Aims 1. Investigate the diet and variation in diet of Ningaloo green turtles 2. Quantify aspects of developmental energetics of Ningaloo green turtles 3. Develop a Dynamic Energy Budget (DEB) model for green turtles 4. Assess the influence of temperature and food availability on aspects of Ningaloo green turtle energetics via DEB theory 3
Dynamic Energy Budget Food Waste Assimilation Somatic maintenance Reserve Maturity maintenance Growth Reproduction Structure Maturity/ reproduction modified from Kooijman 2010 4
DEB building a model food and temperature Equations DEB theory new food and temperature conditions Equations DEB theory parameters predictions measurements new predictions 5
Incubation experiments 27 C 31 C 29 C 30 C 32 C 30±5 C % development 6
Development rate 2.5 32.6 C Development rate (% per day) 2 1.5 1 0.5 0 0 5 10 15 20 25 30 35 40 45 50 Temperature ( C) 7
Hatchlings Yolk free hatchling mass (g) 30 25 20 15 10 5 yolk free hatchling mass yolk mass 4 3 2 1 Yolk mass (g) Hatchling straight carapace length (mm) 78 77 76 75 74 73 72 71 70 0 27 29 30 31 32 30±5 Incubation temperature ( C) 27 29 30 31 32 30±5 Incubation temperature ( C) 0 8
DEB building a model for a green turtle food and temperature Equations DEB theory parameters predictions measurements 9
Model fit Measurement Input Predicted Straight carapace length at hatch (cm) 4.55 4.55 Age at puberty (yr) 29 23 Curved carapace length at puberty (cm) 91 97.98 Maximum reproductive output (eggs/day) 0.3 0.282 10
Investigating maternal effect Clutch H: e b = 0.65 Clutches B and F: e b = 1 11
food and temperature Equations DEB theory new food and temperature conditions Equations DEB theory parameters predictions measurements predictions 12
Acknowledgements BHP-CSIRO Ningaloo Outlook Marine Research Partnership Egg collection assistance- Blair Bentley, Nicki Mitchell Everyone involved in tagging turtles - Mat Vanderklift, Richard Pillans, Mel Trapon, Flavie Delanzy, Zoe Starkey, volunteers etc. DEB collaborators - Starrlight Augustine, Nina Marn Matlab scripts Laure Pecquerie Exmouth DBCA for granting permits 15
Thank you! CSIRO Oceans and Atmosphere UWA School of Biological Sciences Jessica Stubbs PhD Candidate e jessica.stubbs@research.uwa.edu.au t 08 9333 6261 OCEANS AND ATMOSPHERE
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