STUDY NUMBER ; 13.2 



ORGANIZATION ; Institute of Paper Chemistry/Champion Interna- 

 tional Corporation 



TITLE OF STUDY ; Benthic Invertebrate Studies on the Middle 

 Clark Fork River 



CONTACTS ; Larry Weeks - Champion International - 626-4451 

 Loren Bahls - DHES, WQB - 444-2406 

 Gary Ingman - DHES, WQB - 444-2406 



OBJECTIVE ; Annually monitor the benthic invertebrate 

 communities in the Clark Fork River above and below a major 

 pulp and paper mill located at Frenchtown. 



DURATION ; 1956 - Indefinitely 



CURRENT STATUS ; Benthic invertebrate samples are collected 

 yearly during late summer at nine to eleven stations. The 

 study area extends from the outskirts of Missoula to Lozeau 

 (near the confluence of Nine Mile Creek) with the most 

 intensive coverage given to a twenty mile river reach 

 encompassing the Frenchtown Mill. At each station, four 

 replicated Surber samples are collected in riffle areas less 

 than twelve inches deep. All taxonomic work is conducted at 

 the laboratories of the Institute of Paper Chemistry in 

 Appleton, Wisconsin. Identification of specimens is carried 

 out to the genus and species levels as feasible. Various 

 diversity and biotic indices are calculated to ascertain 

 changes in community composition between controls and areas 

 influenced by the mill's effluent. 



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