Comparison of zooplankton density estimated by acoustic inversion method and net sampling

A multi-frequency acoustic zooplankton fish profiler (AZFP, ASL Environmental Sciences) with temperature-salinity and depth sensor was moored at 10 m from the bottom (ca. 30 m) at the mouth of Yamada Bay in Iwate Prefecture, Japan, from 14 January to 16 June 2015 in order to measure volume backscattering strength profiles from the transducer surface to the water surface at four frequencies (125, 200, 455, and 769 kHz). Zooplankton density by...