Can you add the flash floods, mining, and illegal logging too? thank you, 
Chosen Answer:
I guess it would depend on where the fish habitate.
We have a small man made pseudo-stocked pond near my home.
Yearly we have a fishing derby to “clear” the pond. It’s a wonderful outting for the seniors and kids. Not all of the fish are caught but, it reduces their numbers to a sustainable level for the pond over the winter. Barring typical -40C temps.
Flash floods can introduce species of fish into habitats unsuitable to their survival and/or introduce predators to other unprotected native aquatic life.
Illegal logging, while illegal, can help or hurt a spcies of fish. Too many rivers have been dammed for irrigation or power production PERIOD
Many US and Canadian rivers which are essential to the migration and spawing of Trout, Salmon, Grayling ,Northern Pike, Muskelunge …. are being given a new breath of life being provided with “safe passageways” to their spawning grounds. This includes not only waterways but limits if not bans on angling or netting.
Mining …. There’s a can of worms [full pun intended] … My response is already too long and I could go on for another 20 pages. Look into the history of Estevan Sask. and the strip mines which still operate there today [2011].
by: palekna
on: 1st August 11