Sound production of the critically endangered totoaba (Totoaba macdonaldi): Laying the foundation for conservation of this species through passive acoustic monitoring

Little is known about the sounds produced by totoaba, a critically endangered fish endemic to the Gulf of California. In a multi-national effort to aid management of this population through passive acoustic monitoring (PAM), we collected simultaneous acoustic and video recordings of totoaba housed at the Centro de Reproducción de Especies Marinas del Estado de Sonora in Kino Bay, Mexico. Measurements were made of both sexes and multiple age classes. Furthermore, individuals were placed in isolation tanks to measure individual call rates and call-to-call variability. Video from these isolation tanks permitted determination of source/receiver range for source level estimation, as well as association of acoustic with physical behaviors, resulting in identification of potential alarm calls. Totoaba produce a variety of calls, ranging from short duration (<0.03 s), low-frequency (<1 kHz) narrowband pulses to longer, regularly spaced broadband clicks with significant energy over 15 kHz. Call rates and dominant call type depend on both age and sex. Results are used to develop automated pre-processing/detector algorithms for a future PAM system. Quantitative analysis of the performance of these detector algorithms are presented. [Financial support by the Catena Foundation and experiment support by the Centro de Reproducción de Especies Marinas del Estado de Sonora.]