DIDSON imaging sonar was used along 50-m transects to document the mobile fish community in the Rhode River, MD, USA, Indian River Lagoon, FL, USA, San Fransisco Bay, CA, USA, and Bocas del Toro, Panama. Sampling took place in soft sediment and structured habitats. Each fish >10 cm total length was measured and recorded in this dataset. Size spectra analysis was used to analyze the data and code for the analyses is included.