How can we have farm in the sea?

Farmers grow plants and animals on their farms. It is also possible to have a farm in the sea? People in many countries grow freshwater fish from eggs. They move the small fish in to lake and river. The fish live and grow their. People go fishing in these lakes and river. They enjoy catching fish. Fish is also good food. Now Japan grows saltwater fish. Most of them are yellowtail fish. Worker grow the fish from eggs. Every time they feed the fish, they play tape of piano music. They learn that the piano music means food. When the fish are small, the Japanese put them in the ocean near the land. The fish find their own food. Worker also feed them. They play the same piano music. The fish already know this music. They swim toward it and find the food. In a few months the fish are large. The Japanese play the same music. The fish swim toward it and the worker catch them. The Japan gets about 15 percent of their seafood from farms of the ocean.