Satellite Tracking of Dugongs and Green Turtles in Torres Strait and Shoalwater Bay (NERP TE 1.2, 2.1, JCU)

Brief description

This dataset consists of the home ranges and satellite tracks taken from eleven dugongs and ten green turtles. Methods: Fast-acquisition satellite telemetry was used to track eleven dugongs and ten green turtles at two geographically distinct foraging locations in Queensland, Australia to evaluate the inter- and intra-species spatial relationships and assess the efficacy of existing protection zones. Home-range analysis and bathymetric modeling were used to determine spatial use and compared with existing protection areas using GIS. Raw, unfiltered tracking data were collected using fast acquisition GPS satellite transmitters attached to six dugongs (three females and three males) and four adult female green sea turtles near Mabuiag Island, Torres Strait, Australia in July 2009 and September 2010, and five dugongs (four females and one male) and six female green sea turtles (five adults and one prepubescent) in Shoalwater Bay, Australia in June/July 2012. The dugongs were captured using the dermal hold fast technique in Torres Strait and the standard rodeo technique in Shoalwater Bay. At both locations, the dugongs were fitted with Telonics Gen 4 GPS/ARGOS marine units attached to a 3 m tether linked to a padded tailstock harness. The green turtles were captured using the standard rodeo technique, brought to Mabuiag Island (Torres Strait) or MacDonald Point (Shoalwater Bay), and fitted with one of four types of satellite transmitters (Sirtrack F4G 291A, Wildlife Computers SPLASH10 BF-273A and Splash10 BF-273C, or SMRU SRDL 9000x). Each transmitter was attached to the carapace using the methods described in Shimada et al. (2012). Each turtle was released from shore the day after capture. Dugong units were programmed to collect a GPS position hourly; turtle units every 30 minutes. All units were programmed with a five minute repeat in case a signal was not received when the animal surfaced. Home-ranges were calculated for each animal using data from the entire period in which they were tracked and were calculated using fixed kernel density estimation with bandwidths selected by likelihood cross-validation (CVh). Kernel densities and bandwidths were calculated using the Geospatial Modelling Environment (GME), an extension to ArcGIS, with a resolution of 50 m. For a more detailed description of the methods see Gredzens(2014). Format: This dataset consists of shapefiles for the satellite tracks (lines and points) for the 21 animals as well as shapefiles for the calculated home ranges. References: Gredzens C, Marsh H, Fuentes MMPB, Limpus CJ, Shimada T, et al. (2014) Satellite Tracking of Sympatric Marine Megafauna Can Inform the Biological Basis for Species Co-Management. PLoS ONE 9(6): e98944. doi:10.1371/journal.pone.0098944 Data Location: This dataset is filed in the eAtlas enduring data repository at: data\NERP-TE\1.2_GBR-Turtles-dugong-monitoing