Answer:
1° producers: algae, plancton
2° primary consumer: zooplancton
3° secondary consumers: smaller fish and crustaceans
4° tertiary consumers: larger fish, birds and mammals (e.g. tuna)
5° quaternaries consumers: white shark
Sharks are located at the top of the food chain. Thanks to the existence of the shark, the aquatic food chain is kept in total balance and the oceans remain healthy.