Cale was playing around, and caught in net of fisherman. But, that fisherman was kind as he let Cale go.

From that, Cale began to meet the fisherman everyday.

Merman cannot talk to fish, they just can control them, so Cale didn't really care if the fish get caught, since fish is human food.

"You here again!"

Cale look happy to see the fisherman again.