What is the role of the ocean in human economic activity?

The ocean is the largest fishing object. In the oceans, the most large-scale fishing is carried out, which, however, they already know how to grow in artificial reservoirs. Also, it is a treasure trove of various medicines, and of course, of tourist value. In the future, people are planning to use the energy of ocean tides in their economic activities, because it is inexhaustible and its receipt does not harm the environment.