1. An integrated study of the Gladstone Marine System Richard Pillans 11-12 August 2015 1 Long term movement of Green Turtles, Chelonia mydas, in Gladstone Harbour: advantages of acoustic telemetry Turtle movement | 11-12 August 2015 |

2. GISERA & development in Gladstone Harbour Increasing LNG developments But, a long history of Port development & other impacts Lessons & insights from Gladstone are relevant to many other areas of coastal Australia 2 |

3. Background 3 | Commercial boat traffic - AMSA Seagrass - TropWater

4. Background 4 | Commercial boat traffic - AMSA Turtles killed by vessel strike Turtles killed by vessels DEHP 2011

5. Questions What are turtle home range sizes? How does turtle habitat use vary with habitat, tide and time of day? How comparable are satellite and acoustic tagging results? How can turtle habitat utilisation be used to better manage turtle interactions in Gladstone Harbour? 5 |

6. Gladstone Harbour Acoustic Tracking Array 6 Wiggins Island Pelican Banks 24 at Wiggins Island: - no seagrass - high commercial traffic - large scale development LNG Processing Plants 5 km 20 at Pelican Banks: - high seagrass cover - low commercial traffic 44 acoustic receivers

7. Turtle capture and tagging Capture 7 Vemco acoustic tags & receivers Wildlife Computer SPLASH10-F- 296A fastloc GPS tags

8. Turtle capture and tagging Capture 8 Vemco acoustic tags & receivers Wildlife Computer SPLASH10-F- 296A fastloc GPS tags

9. Turtle tagging – Pelican Banks 33 tagged with acoustic tags at Pelican Banks 5 tagged with both satellite and acoustic tags

10. Turtle tagging – Wiggins Island 10 16 turtles tagged with acoustic tags at Wiggins Island 5 tagged with both satellite and acoustic tags Mangroves

11. Results – Population structure Wiggins Island mainly juveniles Pelican Banks mainly adults and sub-adults 11 |

12. Results - Pelican Banks acoustic tags - Detection span (May 2013 – September 2014) GISERA Marine | 12 |

13. Results – Wiggins Island acoustic tags - Detection span (May 2013 – September 2014)

14. Home range estimation Acoustic tags - 1.4 million detections May 2013 – September 2014 (49 tags) Satellite tags – 8400 Fastloc detections May 2013 – September 2014 (10 tags) Home range estimates for acoustic and satellite data obtained using Kernel Utilisation Distribution (adehabitatHR – R) Acoustic detections randomly assigned to a 200 m buffer around each receiver HREF smoothing parameter most realistic given array configuration BOM tide and sunrise/sunset data 14 |

15. Results – Home range estimates for individuals - calculated each month as well over the entire detection duration (Kernel density utilisation) Monthly variation in home range Home range of individual over entire period

16. Results – Home range estimates for all turtles at Pelican Banks - cumulative kernel density utilisation for the population 16 | 50 and 95 % KUD contours for 33 Green Turtles at Pelican Banks Tag location 50 % KUD 95 % KUD

17. Results – Home range estimates for all turtles at Pelican Banks - cumulative kernel density utilisation for the population 17 | 50 and 95 % KUD contours for 33 Green Turtles at Pelican Banks Tag location 1.4 ± 0.2 km 2 6.7 km 2 ± 0.9 km 2

18. Results – Pelican Banks: individual variation 18 | Tag location high degree of overlap with seagrass coverage with individual variation

19. Results – Wiggins Island - cumulative kernel density utilisation for the population 19 | Tag location 50 and 95 % KUD contours for 16 Green Turtles 50 % KUD 95 % KUD

20. Results – Wiggins Island - cumulative kernel density utilisation for the population 20 | Tag location 50 and 95 % KUD contours for 16 Green Turtles 3.8 km 2 ± 0.4 km 2 0.7 ± 0.1 km 2

21. Results – Wiggins Island: high degree of overlap with intertidal mud flats and mangrove lined drains and shoreline with individual variation 21 | Tag location

22. Results – influence of tide ● Greater use of flats during mid-high tide ● Greater use of channels at low tides Wiggins Island Pelican Banks

23. Results – Pelican Banks: strong influence of tide on movement with animals moving onto intertidal seagrass at high tide 23 |

24. Results – strong influence of tide on movement 24 | Tag location High tide Low tide

25. Results – Wiggins Island strong influence of tide on movement with animals moving into mangrove lined drains and shoreline at high tide 25 | Tag location

26. Habitat use – Day vs Night 26 | Tag location

27. Habitat use – Day vs Night 27 | no difference in size of home range at high and low tide between day and night

28. Pelican Banks – Satellite tags 28 | Average Sat tag detection period

29. Pelican Banks – Satellite tags 29 | Average Sat tag detection period

30. Pelican Banks – Satellite tags 30 | Average Sat tag detection period

31. Pelican Banks – Satellite tags 31 | 55 km

32. Satellite tags – resident animal - limitations 32 | Acoustic tag detections Satellite tag detections For all double tagged turtles - 60 times more detections from acoustic tags Tag location

33. Pelican Banks – Satellite and acoustic tags 33 |

34. Pelican Banks – Satellite and acoustic tags 34 | Tag location Acoustic tag Satellite tag

35. Wiggins Island – Satellite and acoustic tags 35 |

36. Wiggins Island – Satellite and acoustic tags 36 | Tag location

37. Satellite and acoustic tags 37 | $60000 – Acoustic telemetry = 45 tags, 30 receivers + deployment $60000 – Satellite telemetry = 10 tags + deployment Satellite tags underestimate home range of resident turtles Acoustic tags generated 1000 – 7000 detections per month Satellite tags generated 20 – 250 detections per month Acoustic tags stay on much longer (years vs months for Sat tags) For resident animals, acoustic tags provide better data for estimating fine and broad-scale movement patterns and habitat use Acoustic tags better for investigating localised impacts (e.g. Port Development)

38. Long term benefits of acoustic tags 38 | Monthly home range is small and stable (but is it really?)

39. Long term benefits of acoustic tags Adults (96 – 114 cm CCL) 39 | Despite small home range, > 50 % move beyond established HR and don’t return

40. Long term benefits of acoustic tags Juveniles (40 – 80 cm CCL) 40 | Juvenile male turtles more nomadic than females?

41. Habitat modelling Implications for management How can we use turtle habitat use to better manage turtle interactions in Gladstone Harbour? Shipping movements

42. Habitat modelling Implications for management Turtle vs ship presence How can we use turtle habitat use to better manage turtle interactions in Port Curtis? Shipping movements

43. Implications for management How can we use turtle habitat use to better manage turtle interactions in Gladstone Harbour? Model of habitat preference and shipping activity Recreational craft

44. Conclusions: effectiveness of acoustic arrays for green turtles ● Satellite and acoustic tags highly complimentary ● Satellite tags best for long distance movements (reproduction) ● Satellite tags underestimate home range for resident turtles ● Acoustic tags provide 60 times more positions for residents within array ● Acoustic tags better for investigating tide and diurnal behaviour ● Acoustic tags providing insights into proportion of resident individuals ● Acoustic tags enable a pool of pre-tagged animals to provide baseline in case of unexpected events ● Methods for permanent attachment of acoustic tags need to be developed

45. Thank you

46. Average depth of a turtle at Wiggins Island No evidence of channel use from depth data

47. Satellite tags – Fastloc data only 47 | + Argos Fastloc