Primary and secondary production in the oceans and hence abundance of macrofauna is limited by light or more often by nutrients. Any oceanic system that injects new or regenerated nutrients into a body of water creates a center of high biological productivity. While classical oceanographers have identified such production areas and depth zones by measurements of physical parameters and net sampling, the fishermen have done it empirically with sonar and other acoustic devices available to them after the end of World War II. The fisheries biologists started extensively to employ acoustical techniques in their abundance estimations, first with analog and later with numerous digital integrators and echo counters using dual or split beam transducers. This development is illustrated with examples from the Peruvian and Northwest Africa upwelling systems, krill abundance at the ice edge, and mapping of superswarms in Antarctica, and salmon and herring populations in Alaska. A next generation of acoustical systems will be used to map the patchiness of herbivores and carnivores foraging on primary and secondary producers. Once patches have been identified, it is possible to measure the physical characteristics of the water masses with patches and hence study the microstructure of front and boundary layers.