1. Estimating reef shark abundance using
video surveys and agent based modelling
in Ningaloo Marine Park
 Supervisor : Mathew Vanderklift.
Marine and atmospheric research, CSIRO, Perth,Western Australia.
1
 Traineeship : Helene Boulloche-Sabine.
Master’s degree “BEST” Biodiversity and tropical ecosystems, Reunion island.

2. Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion
1
What is the abundance of coral reef sharks
in the Ningaloo Marine Park ?
How to make accurate estimate of
an elusive species ?
What are the key parameters to
establish a proxy of sharks’
abundance and how to obtain
information about these key
parameters ?

3. 2
 Knowing the abundance = key requirement !
Using a direct or indirect estimator :
 Each method has its own set of biaises.
Examples :
 Capture, mark, recapture
 Tagging, tracking
 Aerial detection, photographic traps
 Belt transects, stationary point counts
 Underwater video, baited or not.
Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion

4. 3
Underwater unbaited video
Sharks : elusive species
 Estimating the abundance of sparsely distributed, rare and
elusive species is challenging
 Especially where direct observations are difficult
 Minimize the biases on the ecosystem and on animals’
behaviour
 Generate estimates of the density of sharks using
modelling
Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion

5. 4
Agent based model
 The model attempts to simulate the foraging behaviour of
blacktip reefshark
 It requires 3 main components :
3) A way to determine when each modelled individual can be
‘detected’ by the cameras in the model.
1) Statistical distributions describing the lengths of straight-line
movements and the turning angles
2) An algorithm controlling the way each individual interacts
with habitats and with obstacles to movement
Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion

6. 5
Agent based model

Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion

7. 6
 Distribution of the turning angles constitute a key parameter in
the agent based model.
The influence of the scale is very strong
Turning Angles
Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion

8. 7
Sony DCR-HC15E
New campaign will begin in
March 2015 in Mandu.
Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion

9. 8
Raspberry Pi
10 Raspberry Pi cameras are added to the new campaign
Able to record for a very long time : 20 hours
 Can provide information about difference in swimming
behaviour between Dawn, Noon and Dusk.
Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion

10.  Expectations of the Ningaloo project :
1) Obtain additional data for Fobs
3) Get information about foraging behaviour of coral reef shark :
 acoustic data and drones.
2) Sharpen the agent based model
9
Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion

11. 1
THANK YOU FOR YOUR ATTENTION
White tip reef shark, Mandu, March 2014.