How Can We Understand Freshwater Soundscapes Without Fish Sound Descriptions?

The ecological importance of the freshwater soundscape is just beginning to be recognized by society. Scientists are beginning to apply Passive Acoustic Monitoring (PAM) methods that are well established in marine systems to freshwater systems to map spatial and temporal patterns of behaviors associated with fish sounds as well as noise impacts on them. Unfortunately, these efforts are greatly hampered by a critical lack of data on the sources of sounds that make up the soundscape of freshwater habitats. A review of the literature finds that only 87 species have been reported to produce sounds in North America and Europe over the last 200 years, accounting for 5% of the known freshwater fish diversity. The problem is exacerbated by the general failure of researchers to report the detailed statistical descriptions of fish sound characteristics that are necessary to develop PAM programs. We suggest that publishers and editors should do more to encourage reporting of statistical properties of fish sounds. In addition, we call for research, academic, and government agencies to develop regional libraries of fish sounds to aid in PAM and anthropogenic noise impact studies.