Oh yeah, Japan is so well known for the diversitty of its animal species. Maybe their sea creatures, but North-east United States provides many ports as well as animals accustomed to the easy life of urban areas, not to mention zoos filled with exotic animals, something America is well-known for.
It may not be as exciting as a game set in, I don't know, Australia or something, but it won't be as bad as you're making it out to be.
e: I think a game set in the south-east United States would be ballin'. There would be coyotes and raccoons and oppossum and pole cat.. And there would be some awesome Japanese interpretations of Hillbillies.