The movements, diving behaviour and thermal environment occupied by female olive ridley turtles Lepidochelys olivacea in northern Australia were determined through satellite telemetry, during the post-nesting migration. Satellite-relayed data loggers (SRDLs) were attached to the carapaces of 4 female olive ridley turtles nesting in the Wessel Islands of Arnhem Land in the Northern Territory of Australia (Graham Island: 11° 45’ S, 135° 57’ E and Wunpirri Island: 11° 36’ S, 136° 05’ E).
This metadata record, represents several different datasets listed hereafter, which can all be accessed through a multi-WFS service.
CTD - parameters measured by the instruments include time, temperature, and depth. The data represented by this record are presented in delayed mode.
Diving - parameters measured by the instruments include start and end time and longitude/latitude of each individual dive, post-dive surface duration, dive duration, maximum dive depth, intermediate dive depths and times. The diving data represented by this record are presented in delayed mode.
Haulout - a haulout begins when the SRDL has been continuously dry for a specified length of time (usually 10 minutes). It ends when continuously wet for another interval (usually 40 seconds). Haulout data parameters measured by the instruments include haulout start and end dates and longitude/latitude, and haulout number. The haulout data represented by this record are presented in delayed mode.
Argos locations - parameters measured by the instruments include time, longitude, latitude, location quality, along with other diagnostic information provided by Argos (http://www.argos-system.org/). The Argos data represented by this record are presented in delayed mode.
Summary Statistics - as well as sending records of individual events such as dives and haulouts, the SRDL also calculates summary statistics of those events over a specified time period (usually 3, 4 or 6 hours). Summary statistics computed by the instruments include the proportion of time spent diving, at the surface and hauled-out, the number of dives, and the average, standard deviation and maximum dive duration and dive depth during each summary period. These statistics are based on all the data recorded by the SRDL and so are not prone to distortion by variations in the efficiency of transmission via Argos. The summary data represented by this record are presented in delayed mode. Note that it is impossible to subset this particular dataset using a bounding box as there is no latitude, longitude coordinates associated with each entry.
Maintenance and Update Frequency: asNeeded
Statement: Satellite-relayed data loggers (SRDLs, manufactured by the Sea Mammal Research Unit [SMRU], University of St. Andrews, United Kingdom, www.smru.st-and. ac.uk) were attached to the carapaces of 4 female olive ridley turtles nesting in the Wessel Islands of Arnhem Land in the Northern Territory of Australia (Graham Island: 11° 45’ S, 135° 57’ E and Wunpirri Island: 11° 36’ S, 136° 05’ E) using quick-setting epoxy glue. Standard curved carapace length (SCCL) was measured for all individuals prior to SRDL-unit attachment, where SCCL is the distance from the anterior point at midline (nuchal scute) to the posterior tip of the supracaudal (Shanker et al. 2004). Weights were not measured, but we estimated mass from a SCCL-weight relationship derived from olive ridley turtles captured during a World Wildlife Fund for Nature (WWF) Australia program (5 turtles, morphometric measurements available from http://wwf. org.au/ourwork/ocean /oliveridleytrackingbios/). The SRDL function and attachment procedures are summarized in detail elsewhere (Hochscheid et al. 2005, McMahon et al. 2005). However, we modified previous procedures by mounting the SRDLs prior to attachment onto an epoxy wedge (base = 125 mm, width = 70 mm, height = 32 mm, hypotenuse = 92 mm, slope = 20°) with glue so that the antenna would point perpendicular to the sea surface to improve communication with the satellites upon the turtle surfacing (SMRU SRDLs are constructed so that the antenna points forward at an angle of approximately 20°). We observed that the long axis of olive ridley turtles swimming at the surface was ~0°, so the SRDL-wedge configuration appeared to maximize the occurrence of a vertical antenna position when the animal first surfaces to breathe. Argos location data were summarized such that average daily positions were interpolated from the scatter of points available for each day. For this analysis, only high-quality Argos locations of quality class A, 1, 2 and 3 were used (see Hays et al. 2001 for accuracy estimates for each class). We first interpolated these high-quality locations using custom R code (R Development Core Team 2004) developed by D. Pinaud (Pinaud & Weimerskirch 2005) with an interpolation distance set to 0.2 km. Using this interpolated set, the mean latitude and longitude were then calculated for each day of the trip.
Statement: This dataset collection combines the following datastreams: CTD, Argos, Haulout, Diving, Summary Statistics.
Prior to October 2015, these datastreams were described and served separately but with new developments of the portal 1-2-3, they have been combined in a single collection for ease of discovery and data access.
The Traditional Owners of the region
Northern Land Council
Marthakal Homeland and Resource Centre Association
Charles Darwin University (CDU)
Natural Environment Research Council (UK) grant
Australian Academy of Science Visiting Fellowship