The plot revolves around the sailors and captain of a whaling ship, but you could not say it is about whale hunting any more than you could say that "Macbeth" is about removing troubles spots from clothes. The story uses whaling to examine the various motivations of the sailors aboard the ship - especially Captain Ahab. Ahab is obsessed with finding Moby Dick (a large white whale) and killing it. He gives the whale qualities of being ruthless, single-minded and cruel. The irony is that Ahab is the one who really possesses these qualities.

Yes, but it is by Herman Melville (first name, surname), not "Herman."