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     Over the years I have driven along the Columbia River dozens of times from Portland  to 180 miles upstream  where the river turns north into Washington State. 

(Rie Miyazaki is co-author of the Columbia River material, here and on the Intro page).

       I always had the impression that I was driving beside a wide river, with willows growing on sandbars, whitecap waves  due to the strong gorge winds, and water gushing from the power plants of several dams. 

     Finally we  made a series of collections and took river samples from several  sites in the river- (near Multnomah Falls, at Bonneville Dam, at the Dalles, at Umatilla, all in Oregon, and west of  Mesa, Wa. not far north of the Oregon border.)

    We discovered for ourselves  what is clearly stated at an Oregon website: the  river is a series  of dams and lakes, there is no downstream current, and there are no river aquatic insects. (http://www.dfw.state.or.us/conservationstrategy/document_pdf/b-eco_columbia.pdf) (p. 255, An Altered System)


   Several detailed studies have been done on the lower Columbia.  There is a tidal influence from Astoria  where the river enters the ocean upstream to past Portland.  Then the series of dams begins.

See :(http://www.nwfsc.noaa.gov/publications/techmemos/tm26/tm26.htm#o34) and for terrestrial systems, see :(http://www.fs.fed.us/pnw/pubs/gtr512.pdf).


 For the following  regarding the Columbia watershed, see( http://clr.pdx.edu/docs/MCRANS_Final_Rprt.pdf)

p. 4- there are over 400 dams, reservoirs, and  hydroelectric projects;  on the Columbia and Snake rivers there re 18 major dams. Eleven large dams on the main Columbia River turn the river into a series of slow-moving reservoirs.  The  lowest  is Bonneville Dam.

p. 6- Historically the system had  an average to rich bottom fauna.  This included  Trichoptera  and chironomid larvae, mayfly nymphs and mollusks (Roebeck et al. 1954 in Ebel et al 1989).  "Today the main stem of the Columbia River is considered depauperate in species (Ebel et al 1989)".


Field Observations, Aug. 2009


The river at
Richland is in
fact the upper
end of the lake
formed by a
dam at
Umatilla, Oregon.
--- the dot in the
middle of the above
A real river
seems to exist
opposite the
town of Mesa
(map, above).
The Columbai River shore  west of Mesa is gravel and stones.
The substrate between stones is covered with silt and living and decaying plant material.
As the cracked crusts of silt indicate on the rocks above, the river substrate is unsuitable for the original river benthic invertebrates, and no aquatic insects were found in August 2009.  Shells of bivalves were abundant on the shore.


Regarding the quote from ( http://clr.pdx.edu/docs/MCRANS_Final_Rprt.pdf)  -"Historically the  (Columbia) system had  an average to rich bottom fauna",  

the question is:

What species made up this rich bottom fauna?

Evidence below indicates that the Columbia was originally very similar to the current Saskatchewan  River in terms of species in the aquatic insect community (Ephemeroptera only at this point).


Below are historical records, extracted from  publications by Meyer and McCafferty , 2007, Washington and Oregon Mayflies:

Almost all the the following species were shared by the Saskatchewan and Columbia Rivers.  They are still present in the former (see discussion on Home), but apparently long gone from the latter.

Records from Washington--------------------------------------------------------------------------------------------------------

(Benton County, Washington, is often cited below. The Columbia River forms the east boundary of Benton County, and the river forms the west boundary of Franklin County.

Species Accounts:

Baetiscidae, Baetisca columbiana Edmunds, Franklin (County?) near Mesa, Washington, Columbia River.  Reported by G. F. Edmunds.  A similar species, Baetisca  lacustris is found in the Sask. River.

Baetidae, Callibaetis fluctuans (Walsh), Benton County, Wa., Columbia River. A similar species, Callibaetis palidus, is found in the Sask Riv. 

Ephemeridae, Ephemera simulans Walker, Benton County, Columbia River, Hexagenia limbata (Serville), Benton County.  Both of these species are also presently found in the Saskatchewan River.

Heptageniidae, Heptagenia solitaria McDunnough, Benton County, Columbia River, Maccaffertium terminatum (Walsh), Columbia River.  Both genera, plus the species  M. terminatum  are  found in the Sask. River.

Leptohyphidae, Tricorythodes minutus Traver, Benton County, Columbia River.  This species is found in the Saskatchewan River.

Leptophlebiidae, Traverella albertana (McDunnough), Benton County, Columbia River, This species is found in the Saskatchewan River.

Polymitarcidae, Ephoron album (Say), Benton County.  This species is found in the Saskatchewan River.


(The Snake River is an eastern fork forming the Columbia River, and the John Day River enters the Columbia from the south in Oregon)

Baetidae, Camelobaetidius mexicana (Traver and Edmunds), Baker County Snake River and C. warreni (Traver and Edmunds) John Day River (both rivers are tributaries of the Columbia River).  C, warreni is found in the Saskatchewan River.

Ephemeridae, Hexagenia limbata (Serville), Portland  (Columbia River?) and Bonneville Dam.  This species is found in the Saskatchewan River.

Heptageniidae, Maccaffertium terminatum (Walsh), Snake and John Day Rivers. This species is found in the Saskatchewan River.

Leptophlebiidae, Choroterpes albiannulata McDunnough, John Day River.  This species is found in the Saskatchewan River.

Polymitarcidae, Ephoron album (Say), Snake River (east tributary of the Columbia River.  This species is found in the Saskatchwan River.

Missing from the Oregon/Washington  Columbia River data are evidence of the "Southwest" presence- e.g. Ametropus and Lachlania, and "Eastern" representatives such as PseudironMacdunnoa, and Raptoheptagenia.


See Oregon Rivers Introduction for more on the Columbia River.