WAMSI Node 3.2.1 - Diversity, abundance and habitat utilisation of sharks and rays - Summary

From April 2007 to June 2009, six field trips were undertaken to investigate the elasmobranch faunal composition of the Ningaloo Marine Park (NMP), determine the distribution and abundance of species, and examine the habitat utilisation, movement patterns and activity space of selected key species. Dive and longline surveys, passive acoustic telemetry and satellite tracking were used to collect data. Of interest to management, was whether existing sanctuary zones were effective for elasmobranchs as well as the location and timing of aggregation sites reported for some species. Satellite tagging data: Two types of platform transmitter terminals (PTTs) were used, Wildlife Computers (Redmond, USA) smart position or temperature transmitting tag (SPOT4 or SPOT5) and SPLASH tags. Longline survey data Longline fishing was used to survey elasmobranchs outside the reef and was carried out from the Western Australia Fishery Department vessel RV 'Naturaliste'. A total of 111 longline sets were made between Three Mile Camp towards the southern extremity of the Marine Park, to northeast of the Muiron Islands outside the northern limits of the Park; the distribution of these sets are shown in the thumbnail. Of these 111 sets, 17 were in sanctuary zones and 94 in non-sanctuary zones (in the thumbnail picture the hatched areas are sanctuary zones). Lagoon and reef edge dive survey data Snorkel and SCUBA underwater visual surveys were conducted as part of four field trips to Ningaloo in April and June 2007 and August and December 2008. The June and August surveys were restricted to the reef edge on SCUBA, while the April and December surveys were mainly on snorkel and in the lagoon. While the original intention was to provide coverage through the different seasons, poor weather conditions coincided with most of the planned fieldwork (including cyclone 'Nicholas') resulting in re-scheduling of some trips. A total of 137 sites were surveyed between Vlaming Head on the northeast of the Cape to Gnaraloo in the southern part of the Marine Park (see thumbnail picture). Of these surveys, 89 were in sanctuary zones and 48 in non-sanctuary zones (sanctuary zones are shown as hatched in the picture). Acoustic data Elasmobranchs were tagged with acoustic tags and subsequently monitored with acoustic receivers (Vemco VR2, VR2W and VR3) moored on the seabed that constitute the Ningaloo Reef Ecosystem Tracking Array (NRETA). This array is part of the nationwide network of marine acoustic monitoring, the Australian Acoustic Tagging and Monitoring System (AATAMS). A total of 96 acoustic receivers are deployed at Ningaloo Reef between Coral Bay and Tantabiddi. A total of 56 acoustic tags were deployed on six species of sharks and three species of rays in the Ningaloo Marine Park in February 2008. Data is accessible through the IMOS AATAMS website 11 Nervous Sharks (Carcharhinus cautus) 10 Giant Shovelnose Rays (Glaucostegus typus) 9 Blacktip Reef Sharks (Carcharhinus melanopterus) 9 Grey Reef Sharks (Carcharhinus amblyrhynchos) 8 Cowtail Stingrays (Pastinachus atrus) 4 Porcupine Rays (Urogymnus asperrimus) 4 Lemon Sharks (Negaprion acutidens) 1 Tiger Shark (Galeocerdo cuvier) 1 Whitetip Reef Shark (Triaenodon obesus)

Organization: Western Australian Marine Science Institution