It's a little poem that plays on the pronunciation of an island's name. The island is off the coast of Maine was named Isle au Haut by Samuel Champlain.
“Says the summer man, when the fog hangs low,
‘There’s bridal wreath over Isle au Haut’;
But the fisherman says when he launches his boat,
‘It’s gosh darn foggy off Isle au Haut.’ “
As far as I can tell, the author is unknown.