This document discusses using video surveys and agent-based modeling to estimate the abundance of reef sharks in the Ningaloo Marine Park. It notes that estimating abundance of elusive species like sharks is challenging. The study aims to minimize biases by using underwater video and modeling to generate density estimates. An agent-based model is used to simulate shark foraging behavior, requiring data on movement lengths and turning angles. A new video campaign using additional cameras will provide more data on turning angles and swimming behavior at different times of day to refine the model. The goal is to obtain accurate abundance estimates for effective shark conservation in the park.

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
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Problematics
Estimate
abundance
Modelling
& Video
Turning
angles
M&M Conclusion

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