At least some content in this article is derived from information featured in Fantastic Beasts: Cases from the Wizarding World. Spoilers will be present within the article.
This fishing pole belonged to the Landlord of the Siren's Rest. He had it with him when he was attacked at the nearby lake. It bore the marks of the magical beast responsible and the landlord hoped to hang it in the Siren's Rest to draw more visitors to his pub.