Abstract: The present invention relates to the field of monitoring systems, and specifically, to monitoring systems for measuring fish size, fish quantity and total fish biomass in a fish farming operation. The fish are located in a seacage in a body of water. A mobile platform is placed on the surface water above the seacage and is moved in a transect pattern above the seacage. A transducer with associated transceiver attached to the mobile platform generates an echo pattern that is converted by a processor into estimates relating to fish size, fish quantity, and total fish biomass data of the fish located in the seacage.

Abstract: The invention is a system for measuring the rate of food pellet loss in a fish farming operation. The fish are held in a seacage in a body of water. Food dropped into the seacage sinks down through the cage and uneaten pellets exit the bottom of the seacage. An echo transducer below the cage generates an echo pattern that is converted into pellet loss data.