Opportunistic underwater recording of what might be a distress call of Chelonya mydas agassizii

Abstract

All around the world, sea turtles are considered endangered species since their population has declined in the last two decades. In Baja California Sur Mexico, there is a conservation program run by Government Authorities, Industry, and Non-Governmental Agencies focused on vulnerable, threatened, and endangered marine species. In zones of high density of sea turtles, special nets, which allow them to surface for breathing, are deployed monthly for monitoring purposes. Nets are checked every 2 hours during the 24 hours of the census. During one of these checks, a female specimen of Chelonya mydas agassizii was video recorded using an action cam. Posterior analysis of the recording showed a clear pattern of pulsed sound when the diver was at close proximity to the turtle. The signal covers a frequency range of 300 to 800 Hz, which is within the ABRs average audiogram range reported by Ketten and Bartol for Chelonya mydas and within the behavioral Audiogram for Chelonya mydas agassizii that we have previously reported. The video and the sound analyses of this opportunistic recording, which might be a distress call, are presented.