Long ago mermaids loved men and men loved mermaids but they couldn't meet because the sea didn't want. Mermaids live in the caves near the coasts but the sea used to fill them up with water so that the men could never get close. For this reason the fishes don't laugh. They were always sad because their mermaids cried. The sea was touched and created the tide so when the water ebbs the men can go down in the caves and meet the mermaids and when there is the tide the fishes laugh.
29.1.'15
The original poem ("La marea") is in Italian. There is no good translation for a poem. I apologize for mine. Corrections are welcome.