Towed-float GPS telemetry: a tool to assess movement patterns and habitat use of juvenile stingrays

Abstract

GPS telemetry provides high-accuracy spatial data on animal movement; however, it has rarely been used with benthic organisms, such as stingrays, because of their irregular surfacing behaviour or bottom-dwelling habits. This study evaluated the use of towed-float GPS tags to assess movements of juvenile stingrays, with active tracking performed simultaneously for comparison. Four juvenile Urogymnus granulatus individuals (2 females and 2 males; average 32.2-cm disc width) were tracked in April 2016. Individuals travelled 1332.15±269.58m south-east across Pioneer Bay at an average speed of 6.87mmin–1 in 3.7h. Stationary tests demonstrated that the quality of the data obtained by towed-float GPS tags could not be matched by active, acoustic or ARGOS telemetry, reaching, on average, 99% of successful fixes and <15-m accuracy. Location error varied significantly based on the number of satellites detected, with error decreasing as the satellite number increased. This study demonstrated the potential of towed-float GPS telemetry for high-resolution assessment of movement patterns and habitat use of juvenile stingrays in shallow coastal water. If well applied, this technique can increase our knowledge of juvenile stingray ecology and their essential habitats.

Movement tracing and analysis of benthic sting ray (Dasyatis akajei) and electric ray (Narke japonica) toward seabed exploration

“…In these cases, rough positions and traces were usually tracked, but precise position time-course information was not obtained. There is a study capturing the precise movement track by using a high communication rate pinger, but it was not a benthic fish [34], or just using floating sensors which cannot provide terrain information [35]. On the other hand, our study revealed for the first time that the movement of benthic creatures can be traced nearly in real time.…”

Drone-Based Tracking of the Fine-Scale Movement of a Coastal Stingray (Bathytoshia brevicaudata)

“…This study is the first to effectively utilize drones to investigate the fine-scale behavior of rays. While other approaches such as acoustic telemetry [85] and aerial surveillance from a blimp [64] have recently been used to observe the movement ecology of rays, drones present a low-cost, non-invasive opportunity to collect data for marine animals at a very high resolution. Despite criticism of the limitations presented by the battery life of drones (approximately 30 min for most quad-rotor drones such as those used in this study), tracks of rays were conducted for extended periods of time, with an average track time of 13 min and 6 s and a maximum of almost 27 min.…”

Determining Stingray Movement Patterns in a Wave-Swept Coastal Zone Using a Blimp for Continuous Aerial Video Surveillance

“…Approaches such as acoustic telemetry are complicated by the high-energy dynamics that characterise surf zones, hampering acoustic signal detection [20,21]. In addition, the bottom-dwelling habits of stingrays hinder the use of GPS loggers, requiring a towed-float GPS tag which is only useful if the studied animals remain in shallow waters permanently [22]. Even when the use of tags is possible for studying fine-scale movement patterns, they can be prohibitively expensive and require invasive procedures to capture and tag the animals [23].…”