Biodiversity Canada Sask.
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Identification, Taxonomy papers
Environmental Laws, Canada
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Oldman Dam Alberta
Alberta Update 2010
Saskatchewan Update
Saskatchewan River
Saskatchewan River Detail Descriptive
Background Concepts of River Ecology
 Communities, species, origins, distribution
 Rare and Endangered Accounts
Additional species of interest
Current status and conditions
Mystery of St. Louis 06
The River at Saskatoon
Lemsford Ferry
Communities Natural and Altered River
Dams,Research Thermal
 Research Nutrients and Eutrophication
Blackfly Research
undisturbed sites, a comparison
Aquatic Insects
Oregon Winter Ponds
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Notice:  The following data are unpublished in regular journals.  If any information is used from this page or from these pdf's, please credit Rie Miyazaki in particular and also this website as the source and owners of the data.  Thank you.

We have processed samples from May to August, but only the July samples are presented here.

Recent developments have made it necessary for me to make the following statement:  -Copyright is claimed to  all unpublished data, information, and images.  Not for commercial or related use.    Use without permission and proper credit is restricted  to personal  and limited student use. Thank you.

Our summary and conclusions are that the river at Saskatoon shows many signs of pollution and ecological stress.  It has about 50-60 % of the diversity found in the normal river.  The river at Saskatoon is characterized by the lack of many unique species such as those found at Lemsford Ferry; it is characterized by pollution tolerant groups such as Oligochaetae and Chironomidae; it is also characterized by  pollution tolerant species of mayflies such as Baetis tricaudatus, and  stress-indicating caddisflies, namely members of the Hydropsychidae.   The water and substrates at Clarkboro Ferry are very unpleasant esthetically.  Details and data to support  these conclusions are given below.  See photos on the Homepage.

    As aquatic ecologists we have been interested in the river at Saskatoon as a natural system, and have had a number of academic and ecological questions in our minds for many years.  For example, the specialist  reader will know that Saskatoon is the taxonomic type locality for several species of river insects that are now restricted to areas hundreds of km distant.  It seems safe to assume that they are locally extinct in Saskatoon due to changes in the river. So, our question on this page is- What was the natural state of the River at Saskatoon before here was any human impact on the river? What sources of information will provide a valid answer to this question?  Samples from the distant past do not exist, so it seems that the only source of information is to compare Saskatoon with other sites now.

     Clearly, Saskatoon has an impact on the river, although a government report  (click the pdf on the linked page) concludes that the impact is minimal, and provincial and federal government labs located in Saskatoon have not reported any concerns about the river that I am aware of. 

    Saskatoon is one of the two major cities in Saskatchewan,  the other being Regina.  Both have more than 200,000  population.  Only Saskatoon is located on the river.  At Saskatoon, for many years,  raw sewage was put into the river.   Treatment is now upgraded.  There are additional  more or less undocumented and unmonitored sourses of pollution- at least as far as public information is concderned.  We have had experience trying to get information from various levels of government about pollution sources, with little or no success.

Other smaller cities on the river itself are Battleford/North Battleford, Prince Albert, and Nipawin.

Queen ElizabethClarkboro

For a quick overview of our results, see Tables 1 and 2 below.



This page focuses on 7 sites shown on the map below. These are located from B to G on the South Saskatchewan River, plus two sites are on the North Saskatchewan River, opposite F at Borden Bridge, and near Prince Albert.



     This page will be organized around a number of questions.

Question 1.  At Saskatoon, what is the current state of aquatic communities in the River: focus on the present time.  Three sites  will be used to characterize "Saskatoon" as it is currently (data from 2006 plus data from the past 40 years). (See Table 2).

Four sites that have a history of minimal human impact will be used as a "control" for comparison.  Again, see Table 2 below.

Question 2.  At Saskatoon, what was the past condition of the river: focus on the past.   For the answer:   Is  Weldon Ferry (near G) a valid indicator of what is normal for Saskatoon?-  See below for a comparison of E/F with G.

Question 3.  What was "normal" for Saskatoon in the past?  Is Lemsford Ferry a valid standard or control for Saskatoon?-  See below for a comparison of E/F with B.

Question 4.  Borden Bridge is on the North Saskatchewan River, adjacent to Saskatoon (F).  Is it valid to use a nearby site on the North Saskatchwan river as an indicator  for what is normal for Saskatoon?  See below for a comparison of E/F with a site directly north of and adjacent  to F?

Question 5. Cecil Ferry (near Prince Albert)  is on the North Saskatchewan River, adjacent to Weldon Ferry.  Is it valid to use a nearby site on the North Saskatchwan river as an indicator  for what is normal for Saskatoon?  See below for a comparison of E/F with a site near Prince Albert:


Question 1.  At Saskatoon, what is the current state of aquatic communities in the River? 

     Again,we have detailed samples from May to August in 2006 and experience and collections for nearly 40 years, including for  three sites near Saskatoon, namely (1) Clarkboro Ferry (F) a few km downstream from the Saskatoon city limit,  (2) upstream approximately 2 km is Queen Elizabeth Power Station, and also upstream about 10 km is the (3) Cranberry Flats area.  Thus, Saskatoon is indicated by the circle on the river on the following map, and the three sites mentioned are between  E and F.


Numbers 1-3  will  be examined  to characterize  "Saskatoon", and sites 1-3 will be compared individually with 4-7

1."Saskatoon" Queen Elizabeth Power Stataion

2. "Saskatoon" Cranberry Flats

3. "Saskatoon" Clarkboro Ferry

4 "control" Weldon near G

5. "control" Lemsford B

6. "control" Borden Bridge opposite F.

7. "control" Cecil Ferry east of Prince Alber near G.


Table 1.  For convenience, the following table is repeated from the communities page, especially showing the zero insects at Gardiner Dam Outlet (D), the huge number of Chironomidae at Outlook Bridge (E), and the impoverished community at St. Louis (between F and G).


Location           B                 D           E                       F-G          near G
                      Lemsford      Outlet   Outlook Bridge    St. Louis   Weldon  Ferry
Total Insects    1248              0          1840                    133       767
Total species       18              0             13                        8         20
Total Chironom.  214              0         1192                       29        54                                  

Total Trichoptera
Total Mayflies      725             0             203                     84        512
Total Mayfly sp.    11              0                9                       6          11


    1.  "Saskatoon" Queen Elizabeth Power Station

Below is a pdf link with results from near Queen Elizabeth Power Station, upstream  from the Saskatoon city limit (near E).  This site is impacted by Gardiner Dam more than 100 km upstream, but shows signs of recovery when compared with Outlook  Bridge or Cranberry flats (Table 1 above), which are much closter to the dam outlet.  This is also  discussed elsewhere A, elsewhere B.)

queen elizabeth july 06 edite 09.pdf

Summary and comments regarding the pdf and map directly above, --  QEP station (near E).

      As a subjective opinion, backed by data provided on this page, the Saskatoon site QEP station   (near E) is quite ineteresting because throughout  the past decades, I have collected many Ametropus and Pseudiron here.  Other members of the community are quite diverse in the pdf data above..  Unfortunately, Ametropus and Pseudiron have been collected in very small numbers or not at all in the past decade, for reasons that are not known.  In the 2006 samples, thirteen species in total were collected, in contrast to 21 total at Cecil Ferry and Borden Bridge (Table 2 below).  Thus, in 2006, the community was much reduced in diversity (defined here as total number of taxa), and rare and interesting species were missing (the Lemsford Ferry species).  Nonetheless, species such as Metretopus borealis and Hexagenia limbata were present, which is a good sign regarding ecological health.  The fact that about 300 Hydropsychidae caddisflies were present- 1/3 of total specimens- is a suggestion that mild pollution or ecological stress is present.  In sum, the reduced number of total species (e.g. from 21 down to 13, plus the high number of Hydropsychidae, plus the lack of unique species such as are found at Lemsford Ferry, indicate that the community is severeley damaged at the Saskatoon  QEP station site.


Table 2.  Summary of the sites that are presnted in detail on this page, including QEP station just discussed.

Locationdownstream  from  E EFNear Gopposite F,BCircle left of G
Queen Eliz. Power St. Cranberrry FlatsClarkboroWeldonBordenLemsfordCecil Ferry
total Insects8846645167676581248391
Excluding Chiro.5765332517045171022377
Total Species13121320211821
Total Chironimidae3031282505412921414
Total Trichoptera316412??1725421196
Total Mayflies20272122512448725277
Total Mayfly Species108911161116
Oligochaetae77302*1497* 2446466


"Saskatoon" Cranberry Flats- see pdf below

   Cranberry Flats (E)  appears  to be strongly impacted by Gardiner Dams, as is Outlook Bridge (near D) (Tables 1 and 2).  As discussed previously, Outlook Bridge had mostly Chironomidae and Baetis tricaudatus  (over 1000 total insects).  Cranberry Flats samples had 664 total insects, and most were pollution and disturbance indicators such as Oligochaetae (303), Chironomidae (128), Hydropsychidae caddisflies (414) and only 72 mayflies were present.  These 72 represented 8 species, many with 1 or 2 specimens only. Compared with QEP station, both appear to be severely damaged aquatic communities and ecosystems, and this is based on comparison with the "controls" (table 2, above).

Cranberry_Flats_(July_2006) edited09..pdf


"Saskatoon" Clarkboro Ferry- see pdf below

Clarkboro Ferry is downstream from Saskatoon and has been impacted by Saskatoon sewage for many decades.  The area is now supposedly very much cleaned up due to upgrading of sewage treatment. The results from 2006 show that 516 total insects  and 13 species were present in the samples, and that about half, 250, were Chironomidae, and 124 were Hydropsychids.  1497 Oligochaetae were present.  Only 251 specimens were collected in addition to these, and this included  9 species and 122 specimens of mayflies.  The mayflies included members from a number of families, especially Baetids and Heptageniids, plus the genera Brachycercus and Caenis.  Clarkboro is a severely damaged ecosystem based on examination of the aquatic insect and invertebrate community (1497 Oligochaetae) not to mention the general unpleasant appearance of the water and substrates, which, to use everyday terms, appeared slimy and unpleasantly coloured.

Clarkboro July 06 edited 09.pdf


Repeat of Question 1.  At Saskatoon, what is the current state of aquatic communities in the River? 

     At Saskatoon, three sites between E and F, map above, are considered together to define "Saskatoon" ( Table 2).  The three sites  were similar in that  500 - 800  total insects of a dozen species were present in each set of samples, but each site was quite different in terms of details of  balance and species composition.  However, the three were totally unlike the Outlet (D) which had  zero insects, and Outlook Bridge (E), with little in the samples  except Baetis tricaudatus and huge numbers of Chironomidae.

   Chironomidae were abundant at all  "Saskatoon" sites ( compare Borden/Cecil with "Saskatoon", Table 2).  Oligochaetae were what I think is abnormally abundant downstream from the sewage treatment plant at Clarkboro Ferry (F).  Also at Clarkboro Ferry, Chironomidae made up about 50% of total insect specimens.  High Oligochaetae and high Chironomidae are ususally considered to be evidence of organic pollution and nutrient enrichment- e.g. sewage effluent. 

     Regarding indiviuals species, immature Baetis made up a significant % of total insects at Queen Eliz. Power Station, but were minor components at the other two  "Saskatoon" sites. Caenis (20), Hexagenia, and Metretopus were present at QEPS but not downstream.  At Cranberry Flats there were a very large number of immature Heptagenia.   At Clarkboro, 5 categories each made up over 80% of total specimens of mayflies, namely Centroptilum bifurcatum, Heptagenia elegantula, Caenis, Fallceon quilleri, and immature Baetids.


Question 2.  While Question 1 concentrated  present conditions, now, question 2 asks about the past "what was 'normal'  for Saskatoon ? Can we validly look downstream for the answer?  Is  Weldon Ferry (near G) a valid indicator of normal for Saskatoon?-  Below is a comparison of E/F with G.

Weldon Ferry July 2006.pdf

       Both Weldon Ferry and  Saskatoon are on the South Saskatchewan River (E to G, map),  It can be seen from the pdf above and the Table 2  above that the number of specimens in the samples was  similar- -in the 700 range.  However, the number of species is nearly double at Weldon Ferry compared to "Saskatoon" :12 or 13 species. compared to 20.  Oligochaetes are reduced from1497 at Clarkboro Ferry to 24 at Weldon Ferry, and Chironomidae drop from the high numbers in the Saskatoon area to 54 of 767 total insects at Weldon Ferry.  The Saskatoon area suffers from severe ecological disturbance compared to Weldon Ferry based on Oligochaetae, Chironomidae, and total species numbers.  Healty signs at Weldon Ferry are the presence of Odonata, the stoneflies Acroneuria and Pteronarcys, the presence of the mayflies Ephoron and Isonychina, plus high populations of Heptageniidae (218). Numbers of Baetis tricaudatus are "normal" at Weldon Ferry, not abnormally high as at Outlook Bridge.  Also, numbers of Hydropsychidae, which can be indicators of environmental stress such as high nutrient levels, appear in balance at Weldon Ferry.   Weldon Ferry seems to be a desirable, healthy community, in my opinioin, compared to the Saskatoon area. 


Question 3.  What was "normal" for Saskatoon in the past?  Is Lemsford Ferry a valid standard or control for Saskatoon?--A  comparison of E/F with B.

Lemsford transect July 2006 RCC.pdf

     Lemsford  Ferry  (B) and Saskatoon are both on the South Saskatchewan River. More total insects were collected at Lemsford compared to Weldon Ferry (1248 total compared to 767 at Weldon Ferry), and  total Ephemeroptera, total Chironomidae, and total Trichoptera were also higher at Lemsford than Weldon Ferry.  Returning to the Saskatoon/Lemsford comparison, total species were 18 compared to 12 or 13, and "interesting" genera such as Ephoron, Isonychia,  Lachlania, and Traverella were found at Lemsford and not at Saskatoon..  The stonefly Acroneuria and Odanata were also present at Lemsford Ferry, indicating a more diverse and interesting community in my opinion.  Nonetheless, Lemsford is not only quite different from the Saskatoon area, but also somewhat different form Weldon Ferry, especially because of several mayfly genera found only at Lemsford Ferry.    A comparison of relatively undisturbed or recovered sites is the subject of another page.


Question 4.  Borden Bridge is on the North Saskatchewan River, adjacent to Saskatoon (F).  Is it valid to use a nearby site on the North Saskatchwan river as an indicator  for what is normal for Saskatoon?  A comparison of E/F with a site directly north of and adjacent  to F.


Borden Bridge july 2006 edited 09.pdf

At Borden Bridge, which is not impacted by any obvious sources of pollution,  the set of samples yielded 658 specimens, 21 species, 488 mayfly specimens, and 16 mayfly species.  Among mayflies Heptageniidae (Heptagenia and Macafertia), plus Ephoron and Caenis made up about 488 of the 658 specimens.  In addition, dragonflies (Odonata) and the Megalopteran Sialis was present.  Oligochaetes were present (46) but not abnormallly  abundant (compare Clarkboro Table 2); Chironomidae were quite abundant (129).  The unique species found at Lemsford Ferry were not found at Borden Bridge (Traverella, etc), but even so, Borden Bridge had many more species of mayflies than Lemsford Ferry (16 compared to 11 at the latter).  My conclusion is that because of the diversity of mayflies and the low numbers of pollution indicators such as Oligochaetae and Hydropsychid caddisflies (54), Borden Bridge is ecolgically healthy and has a diverse insect community.  It is very different from "Saskatoon" and it is my conclusion  that Saskatoon has a damaged and ecologically altered aquatic insect community.  The validity of the use of Borden Bridge for comparison is justified in my opinion, at least in a general way.

Question 5. Cecil Ferry (near Prince Albert)  is on the North Saskatchewan River, adjacent to Weldon Ferry.  Is it valid to use a nearby site on the North Saskatchwan river as an indicator  for what is normal for Saskatoon?  A comparison of E/F with a site near Prince Albert:


Cecil Ferry July 2006 edited 09.pdf

Cecil Ferry appears to be unpolluted but it is downstream of  the relatively small output  of Prince Albert sewage. Also present at the time samples were taken was effluent of a pulp mill, located on the north side of the river, and not appearing to impact our sample site.  The dark water from the pulpmill could be seen to follow the north shore of the river but not cantact the south shore..  The site was very diverse in species, and was not characterized by indicators of pollution.  Total specimens collected was smallest among the sites discussed on this page  (total 391)(Table 2) but total number of species was tied for highest (21).  There were very few Chironomidae and Oligochaetae, indicating good habitat conditions.  There was great diversity in other groups, including the Stoneflies Acroneuria and Pteronarcys, many Heptageniidae mayflies, the mayfly Ephoron album and the dominant mayfly was Fallceon quilleri.  All things considered, this site is subjectively the most diverse, except for the lack of the Lemsford Ferry unique species.

Saskatoon shows many signs of environmental stress and reduced fauna compared to Cecil Ferry

Clarkboro July 06 edited 09.pdf

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Lemsford transect July 2006 RCC.pdf edited 09.pdf