Fig. 9.3 ( a ) The types of data obtained from acoustic current meters provide a great deal of
information on the physical parameters at an aggregation site and, if such data are combined with
biological information regarding time of aggregation, courtship and spawning, these meters provide
insights into the dynamics of fi sh spawning aggregations. ( b ) General current speed and directions
at a site can be seen in a circulation diagram showing vectors of all currents measured during a
monitoring period. This channel has a net export of water