Hmmmmm boy I could throw an analogy on top of this one......
Bottom line I see is that change is inevitable and what you do about it can mean many things.
Sure the fishing in the great lakes may go down the tubes.
A multibillion dollar industry. But what will letting these fish take over do ? As with every change it's just fear of the unknown.
In several thousand years the great lakes will be only puddles any way!