It's not about the tiny percentage of fish that could be damaged with one mine, it about whether or not Bristol Bay should be a mining district. If you've researched the potential, this is only the beginning.
I'm not sure you understand what Bristol Bay is all about, it's laughable to compare it to Kenai or Valdez. Much of the salmon is shipped directly to Japan (and sold at a high premium) because of its quality. The salmon roe alone has a higher value than all of the fish caught in Prince William Sound put together.
The forces against Pebble may very well make an example out of this project. Don't underestimate the amount of money the seafood industry is willing to spend.
The biggest problem is the "great addition to the economic base" sentence. As it stands now, it's not even remotely worth the risk of tainting the image of Bristol Bay. The revenue generated by the mine isn't taxed adequately. The jobs and surrounding procurement activities from the mine isn't significant enough.
Here's the question you need to ask yourself. With this much risk, should NAK have a market cap of $770M? The answer is obvious.
Sorry, you may have missed it, but Pebble is located in an area already open to mining. I really do not think fisherman in Southeast and Cordova's Copper River want their funds spent protecting the Lodges of Gilliam and his buddies around Iliamna. Pebble will have no measurable effect on Bristol Bay's harvest. Why are you fighting the lodge owner's battle?
Not sure you understand what the term "mining district" means. Ever been to Idaho's silver valley and their EPA Superfund sites? That's a mining district. There's nothing wrong with that in Idaho because there isn't a competing exploitable natural resource that must co-exist with mine runoff.
There's a bull market in all metals. If you want to win, you need to pick the right companies with minimal risk. If you don't grasp this concept, you will be one of the very few who recognized the opportunity but chose poorly (emphasis on the word "poor").