Sea serpent stories occurred by the hundreds back at the turn of the century. Then, the stories were stretched until they were unbelievably impossible. Then people scoffed, because of course the stretched stories were impossible. Then the actual fish which caused the original stories appears and nobody even notices or cares.
Sounds similar to another tall tale I remember hearing about. Probably he already returned, it's just that nobody noticed or cared. Guess they were all too busy waiting for the world to end.
