Spatio-temporal occurrence patterns of young sharks in tropical coastal waters

Journal Publication ResearchOnline@JCU
Yates, Peter M.;Heupel, Michelle R.;Tobin, Andrew J.;Simpfendorfer, Colin A.
Abstract

Understanding spatio-temporal patterns in shark occurrence is critical for assessing the ecological role of a species, its vulnerability to human impacts and environmental change, and the efficacy of conservation and management strategies. Investigating these patterns can also develop an understanding of the functioning of coastal shark nurseries. In this context, we undertook a multi-year fisheries-independent survey of shark occurrence along a 400-km stretch of tropical coastline. Logistic regression was used to identify spatial, seasonal and inter-annual variations in the occurrence of neonate and young-of-the-year (YOY) blacktip Carcharhinus limbatus/Carcharhinus tilstoni, pigeye Carcharhinus amboinensis, scalloped hammerhead Sphyrna lewini and spot-tail Carcharhinus sorrah sharks. Results indicated interspecific variations in occurrence. Seasonal variations characterised the occurrence of YOY pigeye, YOY spot-tail and neonate blacktip sharks, whereas spatial variations were more pronounced for YOY blacktip and scalloped hammerhead sharks. These results suggested that the occurrence of young sharks may be more complex than would be predicted by the timing of parturition alone. In addition, spatial heterogeneity in occurrence suggested that proximate bays are likely to vary in terms of the services they provide to young sharks.

Journal

Estuaries and Coasts

Publication Name

N/A

Volume

38

ISBN/ISSN

1559-2731

Edition

N/A

Issue

6

Pages Count

12

Location

N/A

Publisher

Springer

Publisher Url

N/A

Publisher Location

N/A

Publish Date

N/A

Url

N/A

Date

N/A

EISSN

N/A

DOI

10.1007/s12237-015-9952-4