Отчего вода в море солёная

The fisherman caught one fish, but not a gold one, but an ordinary one. He was walking home through the forest and met Leshy, who was in trouble. The fisherman helped him, treated him to a fish and received a reward from Leshy for his kindness - a mill that can grind salt and give him any food... if you know how to ask for it. The fisherman has healed well! But the happiness of others excites envy. The merchant stole a mill to grind salt, but was punished for greed - he drowned along with the ship. And the mill continues to work at the bottom - that’s why the water in the sea is salty.