In the summer 2015 edition of Trout, they published something akin to an executive summary for their State of the Trout report and I believe it is worth your time to read the article in Trout magazine and also worth your time to read through the entire report at tu.org.
I would include it here, but you know mountain internet being what it is (some poor version of the internet in 1998) the file is too big for my current provider's speed, so go to the link and look for it (it isn't hard to find right now).
The authors of this study dedicated it to the memory of Dr. Robert J. Behnke and I would like to also take this time to encourage you to purchase Behnke's Trout and Salmon of North America book, a book that has never disappointed me in the almost 13 years I've owned it.
I think if you read this report and dive into Behnke's book you will be as up to speed as anyone as to the state of native trout in North America as anyone. You'll only lack the fisheries biology degree.
I just want to give you a few highlights, I feel it my job as a member of Trout Unlimited and as someone as interested in the restoration and conservation of coldwater fisheries as I am to point others to valuable source material.
- 25 of 28 native North American trout species still exist today
- Six are threatened or endangered today
- 13 of 25 or 52 percent reside in less than 25 percent of their historical habitat and are threatened by at least one major threat
- All of our native trout have at least one moderate risk factor
- The persistence of our native trout is threatened by a loss of diversity in gene pool, geography and life history
- Non-native species and climate change are the most serious threats to our native trout
- And most of our native trout species face multiple threats from water diversion, non-native species, climate change and energy development
Well, I don't want to go into a lot of depth when the authors of this report have already done the legwork. Go read the report and buy Behnke's book. And don't forget that saving wild/native or natural salmonids is an incredibly selfish act. You probably will save mankind in the process.