When I think of fish and the Missouri River near where I grew up, I think of paddlefish, several kinds of catfish and suckers, and sturgeon. That was before the Oahe Dam was completed. When I think of fish and the Saskatchewan River, I think of - well, nothing really- maybe an impressive sturgeon's head cut off and left on the river bank at Cecil Ferry, or lonely fishermen at Borden Bridge or the weir at Saskatoon- seldom with any fish to show for their efforts. So given the nature of the benthic communities and insects, what about fish?. I suppose dams and sewage impact fish as well as the benthic community.
The Saskatchewan River is quite different, and excellent information on the common fish species of Saskatchwan is found at: http://www.swa.ca/Publications/Documents/FishSpeciesOfSaskatchewan.pdf. Fifty eight species are found in the entire Province of Saskatchwan, about 20 are "sportfish", and some are restricted to the northern forests and subarctic (grayling) or the semiarid south and southeast of the Province (catfish). Absent from the Saskatchewan River are paddlefish and river catfish, but present are sturgeon, various pike, and suckers, I have not found a web source which highlights the native species of fish of the Saskatchewan River System, nor any information on the impact of dams, sewage, or nutrient enrichment on the breeding habits, reproduction, growth, or disribution of fish. Possibly these factors are as damaging to fish as they are to the insect communities.
They (above link) mention that dams are a barrier to upstream movement of fish, but the website does not indicate knowledge of how dams affect rivers in other ways and how these changes might have an inpact of fish such as sturgeon. Their information on the life cycle of sturgeon indicate that life cycle events are temperature sensative, so presumably dams that alter temperture are important.
It is well know that at present the Govt. of Sask. is spending large amounts of money for consultants and others to study the very widespread sturgeon, presumably in relation to the planned dam at the river forks, --see Home for information and links about future threats.
These present expensive and extensive studies on sturgeon appear to be better late than never. The Province has already built three major dams on the South and Main Saskatchewan Rivers, each dam wiping out the native fish as well as original river communities above and below the dams. See dams. Do they understand the impacts of their dams in the past or are they just starting? The present studies are very good for politics and public relations, as well as good for paid consultants and others with connections. But using presently available informatin anyone can see that the dam will destroy the fish populations as well as the rest of the natural river communities, in spite of the announcements in the public media by the proponents that the dam will have no impact on the environment. Very strange. Environmnental laws in Canada and Saskatchwan laws do virtually nothing to protect the river from the big threats.
For more information on Saskatchewan, Google "Fish- Encylopedia of Saskatchewan" for a list of Saskatchean species.