First of all we are a part of "nature." Nature with or without us has a sense of humor that's especially wicked when it comes to what species are where and the attempts of mankind to move or remove species. From huge snails to rabbit and on to various fish we've moved and then tried to remove critters and in most cases wasted huge amount of resources and time. In many cases we've done good: For instance take the entire North Platte drainage from around Casper, Wyoming to it's headwaters in Colorado. Nature made it beautiful trout water but gave it no trout so along came the white man who introduced trout and they are doing fine to this day in large part. As for me I consider introducing German Carp to the US a great one also. Superb fly fishing quarry, good eating, for sure, and big ones are plentiful enough so that most everyone has them close by. Here in Wyoming, all too often, we have some great fishing waters but unfortunately our F&G are just noit with it as far as keeping us warm and cool waters species anglers happy. He** they even stock city ponds with trout instead of the much more fun and kid friendly and catchable bluegills, perch and crappie!