Another informative link, thank you.
I mostly fish the Upper Bow, and The Highwood, they are close to home. Retiring has allowed me to explore my home waters to a degree I never could before. I haven’t seen a stonefly during the summers of 2018 or 2019 on my home waters. Not one. I normally see them this area in early June to mid-July over the past 15 years.
I do not have a huge interest in entomology, and identifying mayflies is challenging because I can’t always catch one. (I use my hat, sometimes I get lucky and one just lands on me, that is best). The fine details are hard to catalogue. The dark ones look just like the picture above, especially those random dark patches on otherwise clear wings. The late summer and fall Green Drake hatch was invisible to me during summer/fall 2019. I did not see any. Very few dark Mayflies all season. Lots of small pale and yellow sometimes with a greenish tinge. (Yellow Sallies I believe). I did not see any caddies. Dry fly action was slow and I was working on improving nymphing skills so the two dovetailed nicely and I noticed my catch rate from my diary stayed constant by going deeper with nymphing.
Banff and Canmore both have state of the art sewage treatment plants. Since the last major upgrade a couple of decades ago, the fishing dropped off noticeably in my direct experience in this area and this is supported anecdotally by fishing acquaintances, guides and a locally raised conservation person who now lives and works in BC.
This has left me with the perplexing conclusion that some kinds of effluent from sewage plants were good for the bugs and the fish. Is that the same as being good for the water itself? Or humans? Since the “clean up”, bugs and fish have declined. Is the water better?
I am still mulling over which changes I am going to make for this coming season (20/21). We have a problem and I will be part of the solution. One thing I am considering is only fishing stocked waters period. I will give the wild fish (the naturals, the wilds and exotics) a break.