How does the food chain work

The food chain works like, us humans are at the top we eat everything below and because we are at the to of the food chain nothing eats us and everything below gets eaten. OK think about it like this the small fish eats the plankton and the medium fish eats the small fish and so on the big fish eats the medium fish and then the human or shark eats the big fish

The zone your looking for is the intertidal zone.