Assessment of shark sighting rates by aerial ... - Fisheries Reports

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ii Contents LIST OF FIGURES Figure 1. (A) Tracing the white shark outline for all analogues. (B) An in-situ hammerhead shark analogue with snorkeller alongside...................................................................... 8 Figure 2. (A) Study location on the NSW coast. (B) Representation of the deployment grid showing the six 5 km-long transects flown by each aircraft per trial ............................ 9 Figure 3. (A) Google Earth image of 30º quadrilaterals accounting for likely errors in shark analogue sightings. (B) Quadrilaterals also showing reduced 15º and 22.5º leeways. 11 Figure 4. Depths at which shark analogues were sighted by fixed-wing and helicopter observers maintaining their position at 500 ft (~150 m).............................................. 14 Figure 5. Percentage of validated analogue sightings with cumulative distances....................... 16 Figure 6. Percentage of validated analogue sightings per aircraft with relative contribution of different trial treatments............................................................................................... 17 Figure 7. Number of validated shark analogue sightings with three levels of sighting angle leeway for each aircraft................................................................................................ 19 Figure 8. Proportion of validated shark analogue sightings per aircraft per day, with secchi disk measurements overlayed.. .................................................................................... 20 Figure 9. Proportion of validated analogue sightings per aircraft per day, with wind, sea state and cloud cover overlayed. .......................................................................................... 22 Figure 10. Nnumbers of sightings per 100 kms during coastal patrols of NSW beaches ............. 25 LIST OF TABLES Table 1. Analysis of variance examining the effects of aircraft type, substrate depth and shark analogue type on sighting depth......................................................................... 14 Table 2. Percentage of validated shark analogue sightings with cumulative distance............... 15 Table 3. Regression analysis of environmental factors on fixed-wing and helicopter observer sighting rates. ................................................................................................ 21 Table 4. Analysis of variance examining the effects of aircraft type and flight direction on coastal sightings........................................................................................................... 23 Table 5. Number of reported sightings by fixed-wing and helicopter crews during 10 days of coastal patrols. ............................................................................................................. 24 Robbins et al. Assessment of shark sighting rates by aerial beach patrols
Acknowledgements iii ACKNOWLEDGEMENTS We wish to thank both the fixed-wing and helicopter staff and crews for their generous assistance with this project. We also thank P. O’Connor and A. Genders for logistical support, D. Collins for valuable statistical advice and S. McGreal for entry of the aerial patrol data. LCDR R. J. Kyle and CPO G. Jesser of the Royal Australian Navy and M. Carr of the Jervis Bay Marine Park are thanked for their support of this project. This project was funded through NSW Department of Primary Industries Shark Meshing (Bather Protection) Program. Assessment of shark sighting rates by aerial beach patrols Robbins et al.
Page 1 and 2: Assessment of shark sighting rates
Page 3: Contents i TABLE OF CONTENTS TABLE
Page 7 and 8: NSW DPI 5 1. BACKGROUND 1.1. Aerial
Page 9 and 10: NSW DPI 7 2. METHODS 2.1. Study loc
Page 11 and 12: NSW DPI 9 The six flight transects
Page 13 and 14: NSW DPI 11 A B Figure 3. (A) Google
Page 15 and 16: NSW DPI 13 3. RESULTS 3.1. Depth ex
Page 17 and 18: NSW DPI 15 3.2. Distance experiment
Page 19 and 20: NSW DPI 17 Percentage of analogues
Page 21 and 22: NSW DPI 19 Number of analogues sigh
Page 23 and 24: NSW DPI 21 Table 3. Regression anal
Page 25 and 26: NSW DPI 23 3.4. Coastal aerial patr
Page 27 and 28: NSW DPI 25 Number of sightings per
Page 29 and 30: NSW DPI 27 too deep, or are in wate
Page 31 and 32: NSW DPI 29 4.3. Conclusion Severe l
Page 33 and 34: NSW DPI 31 Clark CW, Brown MW, Cork
Page 35 and 36: NSW DPI 33 Rowat D, Gore M, Meekan
Page 37 and 38: NSW DPI 35 No. 27 Rowling, K.R. and
Page 39 and 40: NSW DPI 37 No. 82 Silberschnieder,

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