Marine parks for reef sharks: shark movements at Ningaloo Reef

Conrad Speed, Mark Meekan, Iain Field, Clive McMahon, Rob Harcourt, John Stevens, Richard Pillans, Russ Babcock, Rory McAuley, Corey Bradshaw

Threats at Ningaloo• No commercial shark fisheries• Development• Recreational fishing ~18,000 fishers P/Y (Smallwood & Beckley 2012)

4.2 % recapture rate vs 5.5 % for commercial fishery (Stevens et al. 2000)

Background• MPA design requires ecological data• Movement patterns lacking for most species• Spatial and temporal patterns• Acoustic monitoring (AATAMS)

Ningaloo Marine Park• NMP established 1987• Sanctuary area 883.65 km2 (34%)• Mangrove Sanctuary 11.35 km2

• Mangrove habitat / reef / sand• NMP mangrove habitat < 1%

High diversityCarcharhinus amblyrhynchos

Carcharhinus melanopterus

Negaprion acutidens

ObjectivesSanctuary use by reef sharks• Sanctuary more effective for juveniles?• HR smaller for juveniles?• Residency higher for smaller sharks?• Long-distance movements adults?

Tagging & monitoring

Tagged sharks

• Blacktips (n=10) adults and juveniles• Greys (n=10) adults & juveniles• Lemons (n=5) all juveniles

Temporal detections

Diel patterns

Sanctuary use by residents (n=12)

• Greys 93 %

(n=2)

• Blacktips 45 %

(n=7)

• Lemons 63%

(n=3)

<1 % in sanctuary

58 % in sanctuary

98 % in sanctuary

Kernel ‘hot spots’

Home range

?Adults = 12.8 km2 (±3.12)

Juveniles = 7.2 km2 (±1.33)

MCP =19.56 km2MCP =0.61 km2 (±0.04)

Long-distance movements

260 km

Pupping?

X 5

Adult females

Long-distance movementsTag # Species MLD (km)8229 C. amblyrhynchos 80.5

53414 C. amblyrhynchos 61.8

53351 C. amblyrhynchos 12.8

53355 C. amblyrhynchos 11.3

53347 C. melanopterus 137.8

53361 C. melanopterus 61.8

53344 C. melanopterus 16.1

8218 C. melanopterus 13.2

Conclusions• Highlighted need for ecological data for MPA design• Site fidelity & residency high• Sanctuary offers greater protection for juveniles• Long-distance movements (pupping?)• Extend sanctuary southward

Acknowledgements