Informe preliminar sobre tortugas marinas en Laguna San Ignacio: 2009
William M Megill1, Volker Koch2, Robert P Templeton1, Agnese Mancini2, Amee J Lewis3, Rianna E Burnham1, Ranulfo Mayoral4
1 Ocean Technologies Laboratory, University of Bath, UK
2 Dept de Biologia, Universidad Autonoma de Baja California Sur, Mexico
3 School of Ocean Sciences, University of Bangor, UK
4 Grupo Tortuguero de las Californias, Laguna San Ignacio, Mexico
Abstract
Este reporte sintetiza las actividades de investigación de la tortuga prieta, las cuales se llevaron a cabo en junio del 2009. Ese verano la investigación tuvo cuatro objetivos. El primero fue contribuir al esfuerzo existente de monitoreo de esta especie en la Península de Baja California. El segundo fue determinar las tasas de mortalidad de la tortuga marina y sus causas en el área de San Ignacio. El tercero fue determinar el uso que le dan las tortugas al hábitat de la laguna, y el cuarto fue determinar qué posición tienen en la cadena alimenticia de la laguna. Turtles were captured mostly in the upper reaches of the lagoon using closely monitored entanglement nets, processed ashore, then released close to where they were captured. Turtles were measured, weighed, and flipper tagged. Some were selected to be tracked using a surface buoy equipped with a VHF transmitter and GPS recorder. Two turtles were outfitted with a carapacemounted underwater camera. Due to equipment failures, only one useful GPS track was obtained. Behavior during this track was not different from that observed in previous years. Two underwater movies were obtained, demonstrating that the attachment method worked and that simple inexpensive (and therefore expendable) cameras are sufficient for recording the animals’ behavior. Stable isotope analysis was conducted, and preliminary results suggest that there are two feeding strategies present among the turtles in the lagoon: one focused entirely on eelgrass, and the other split between eelgrass and invertebrates. No correlations were found with any of the turtles’ life history parameters,