While is it widely known that numerous families of fish produce sound for communication, discerning when, where, and who is more difficult. Recent developments in passive acoustic technologies have facilitated marine bioacoustic studies to effectively monitor soniferous fishes. Because acoustic data can be collected over a wide range of habitats and depth for long periods of time, passive acoustic monitoring can map and monitor marine species to efficiently provide year-round information on distribution. This presentation reviews data recorded using moored passive acoustic arrays and hydrophone-integrated gliders. Low frequency (50–6000 Hz) sounds recorded by these methods provide a better understanding of the diurnal and spatial distribution of known fish calls (e.g., red grouper). However, this is seemingly overwhelmed by the vast number of sounds produced by unknown species. Instrument and anthropogenic noise, managing the large of amounts of data collected, and identifying the source of previously undocumented sounds, are just some of the challenges passive acoustic monitoring presents. The connection between sound and important behavior, including courtship and spawning, the application for fisheries management, and the potential impacts of aquatic noise on critical behaviors that affect populations exemplifies the need to overcome these issues.