Shelf-scale mapping of sound production by fishes in the eastern Gulf of Mexico, using autonomous glider technology

Autonomous gliders are a relatively new technology for studying oceanography over large time and space scales. We integrated a hydrophone into the aft cowling of a glider and used it in a 1 wk, shelf-scale deployment on the West Florida Shelf to detect and map fish sounds in the ocean over a large spatial scale. In addition to red grouper and toadfish sounds, at least 3 unknown biological sounds suspected to be produced by fish were identified through manual analysis of the acoustic files. The biogeography of these fishes was identified by mapping the occurrence of sounds along the glider track. Sounds produced by red grouper and toadfish were detected throughout the day predominately in bottom depths >40 m. Conversely, the 3 unknown biological sounds were detected exclusively at night over varying bottom depths. Glider technology provides a reliable and relatively inexpensive method to collect acoustic and environmental data over large spatial scales while maintaining a high rate of successful retrieval.