Long-term fish monitoring in the Southern California Bight

Abstract

While over 100 fish families produce sounds during behaviors like spawning, aggression, and feeding, passive-acoustic sampling is not used commonly for long-term fish population monitoring. Fish sounds consist mostly of low-frequency pulses of variable duration, number, and repetition rate, but it is often difficult to identify their sources to species. For example, underwater sounds from marine life have been studied in the Southern California Bight (SCB) for over 60 years, but because the sound producing fishes are difficult to locate and identify visually, their sound production remains poorly understood. The spatial and temporal distributions of the likely fish sounds recorded in SCB were analyzed, but the species producing those sounds are generally unknown. Where the species are known, more information is needed on the seasonal and interannual variations of their sound production if the passive-acoustic records are to be used to estimate their abundances and distributions. We show that sound charact...