All those stories are oral and passed around by fisherman. You'll need to talk to them in person or over the phone, asking them questions and documenting their orally passed stories. Make the first collection of these stories as well as the first person to officially write them down.
As for the actual topic... Fish usually have sharp ridges or actual teeth on their mouths that feel unpleasant to touch. Just sticking a finger in to pull out the hook is awful enough.