UC San Diego

We evaluate the feasibility of estimating zooplankton biomass using acoustic Doppler profilers (ADP) as deployed on autonomous ocean gliders. A Sontek Spray ADP mounted on a Mocness net was used for simultaneous collection of zooplankton and measurement of acoustic backscatter (ABS). Zooplankton biomass was estimated from optically scanned plankton samples. We found a direct proportionality between ABS and the summed cross-sectional area of the zooplankton as well as with the estimated zooplankton carbon biomass. ABS at 750kHz was most closely related to the summed cross-sectional area of zooplankton and micronekton greater than 1.6 mm equivalent circular diameter. © 2012 The Author.