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MEMORANDUM 



TC: Wilbur Rchmann, Project Manager, Kootenai Falls, FSD, DNRC 



FROM: Fred Robinson, Aquatic Ecologist, FSD, DNRC AfjR 



DATE: September 11, 1980 



RE: Field Work on the Kootenai River below the Falls. 



Data from electrofishing done by DFWP in the Throops Lake section 

 of the Kootenai River has been taken by some to mean that the quality of 

 the trout fishing below Kootenai Falls is poor. Relatively few trout 

 were captured in the section and they comprised only about 3% by number 

 of all fish caught. However, conversations with local fishermen indicate 

 that the trout fishing in these areas is actually quite good, although 

 not as good as above the falls. Also, trout fishermen in the falls and 

 footbridge area have been observed to be quite successful. There are a 

 number of possible reasons for these discrepancies between electrofish- 

 ing data and fishermen success. First of all, most of the electrofish- 

 ing was done from 1971-74 when the shocking equipment was not as efficient 

 as now. Secondly, the shocking in 1978 was done in a canyon area where 

 deep water and steep canyon walls make sampling with electricity diffi- 

 cult. Lastly, fish populations in the Throops Lake area may not be 

 directly comparable to the immediate falls area because of habitat diff- 

 erences and because of the further distance from upstream recruitment 

 areas. 



Because the dewatered stretch and outlet area of the proposed 

 Kootenai Falls facility had not been sampled and because of the dis- 

 cussion in the preceeding paragraph, I attempted to gather some data by 

 gill netting in these areas during the first week of August, 1980. DFWP 

 standard gill nets were used (these nets are 125 feet long and comprised 

 of equal sections of 3/4-inch, 1-inch, l' 4 -inch, l'^-inch, and 2-inch 

 meshes). Two nets (one bottom and one surface set) were set overnight 

 in each of two different locations. Specifically, these locations were 

 the cove areas at the Koot Creek gravel bar above the foot bridge and 

 adjacent to the Antler Lodge a couple of hundred yards below the pro- 

 posed outlet site. The results were interesting. The Koot Creek nets 

 yielded 16 fish, 12 of which were trout averaging 10.7-inches in length 

 with a maximum of 16-inches. The Antler Lodge nets yielded 19 fish, 9 

 of which were trout having an average length of 12-inches and a maximum 

 of 14'j-inches. The numbers of fish caught in these sets are greater 

 than is usually expected for river sets in northwest Montana. This data 

 is useful in that it indicates that trout are apparently more abundant 

 and make up a larger proportion of the fish population in the area than 

 previously indicated by shocking in downstream areas. This conclusion 

 was further comfirmed from observations by divers in the outlet area who 

 were looking for white sturgeon at this time (this will be written up by 

 Pat Graham, DFWP). 



