A new method for the determination of at-sea activity in sea turtles

Interpretation of diving profiles of aquatic animals would be considerably enhanced by additional behavioural information. A new sensor is presented h ere which records animal movements. This sensor was tested on a captive log gerhead turtle Caretta caretta which showed similar activity patterns to fr ee-living green turtles Chelonia mydas. A computer program with user-select able options was developed to analyse the data consistently and rapidly. Us ing our sensor we calculated the total resting time, which differed by less than 5% from the real resting time when the sampling interval was 2 s. The method was additionally tested for different sampling intervals to find ou t its applicability for field studies.