30 years ago in my province, the waters ran deeper, cooler and were more open. The bottoms were more gravely, and fish populations more abundant.
Now our natural Atlantic salmon runs are almost extinct (there is a stocked population that runs but they are weaker and more susceptible to disease and other issues.)
Many rivers, streams, and estuaries are choked with silt, from run off and filled with nitrates, fertilizers, algae, weeds and other oxygen eating nutrients caused by estuary muscle farming, or agricultural practices. This has caused many rivers to turn anoxic making things even more difficult for fish species.
Plus the mean seasonal temperatures have risen and warmer waters have caused more problems.
Finally, we suffer devastating fish kills annually now. The poor trout and salmon won't have a chance at this rate. So yeah, things could be a lot better at this end too!!