BIOLOGICAL INFORMATION FROM AN ACOUSTIC DOPPLER CURRENT PROFILER

Acoustic Doppler Current Profilers (ADCPs) are now used routinely by physical oceanographers. A by-product of the signal processing for calculating the Doppler shift used to determine current velocity is the intensity of the acoustic backscatter, and this, in turn, is a measure of biomass. ADCPs can therefore potentially provide biological oceanographers with quantitative information, collected routinely and non-intrusively in near real time. If these acoustic measurements are obtained concurrently with hydrographic data, the possibility of collecting quantitative biological information on the same time and space scales as physicochemical data becomes a reality. ADCPs have been routinely operated on NERC ships for several years. Examples of the types of biological information which can be obtained are described here in the hope that this will stimulate other users to make use of a potentially valuable source of data.