Tracking Caretta caretta: Movement patterns following rehabilitation in Malta
Martina Cutajar, Celine Ferlat, Vincent Attard, Anthony Gruppetta
Martina Cutajar (email@example.com)
Loggerhead turtle, Caretta caretta, GPS, Satellite, Tracking, Mediterranean, Malta
GPS tracking through the use of satellite transmitters has proved to be a useful technology in identifying migratory patterns in juvenile and adult sea turtles, despite being a relatively new tool in behavioural biology. This technology has allowed tracking to take place over larger areas and for longer periods of time than previously possible. Loggerhead sea turtles (Caretta caretta) are able to travel over large distances throughout their life, being able to travel up to 13,000 km in one year, visiting distant areas and often demonstrating complex patterns of movement both as juveniles and adults. However, information on the tracking of loggerhead turtles rehabilitated and released from the Maltese islands is scarce. This study followed the paths taken by five loggerhead sea turtles, four of which were juveniles while one was a full male adult. All turtles were rescued in Maltese waters and rehabilitated at the Aquaculture Directorate at Fort San Luċjan. The turtles spent between 205 and 1550 days at the rehabilitation centre, depending on the severity of their injuries. Three of these turtles were missing either a front or a hind limb. Turtle movements were recorded as X-Y coordinates using Argos System Applications. This information was gathered using Collecte Localisation Satellite (CLS). Following release, all five turtles were observed to frequent the same main region to the South of the Maltese islands, typically the Libyan and Tunisian neritic coastal zones, with few discrepancies also being recorded. The maximum daily speed recorded ranged between 2.4 and 8.0 km/h. The total distance travelled by the turtles under study ranged between 1375 km and 3273 km in 92 and 292 days respectively. The five turtles covered similar mean distances (11.2 – 22.4 km/day), despite differences in their life-stages and physical abilities. These results suggest that despite their physical limitations, turtles having missing limbs moved at speeds and covered distances comparable to their fully able counterparts.