The sea and its resources as an ecosystem

Energy from the sun is transferred via marine plants, marine herbivores to primary and secondary carnivores and even man himself with some loss of energy at each stage.
Inorganic materials from sea water are extracted and returned during this sequence of processes. Some data suggests that open oceans are only about twice as productive as deserts and that continental shelves are about ten times as productive. Coral reefs and estuaries may be as much as forty times as productive.
The interrelationships between changes in current patterns, fish, birds and man in the case of the Peruvian anchovy underlines the interdependence of various components in marine systems.