STUDY NUMBER ; 2.11 



ORGANIZATION ; Montana Department of Fish, Wildlife and Parks 

 ( MDFWP ) 



TITLE OF STUDY ; Evaluation of Toxicity of Clark Fork River Water 

 to Fingerling Rainbow Trout at Various Locations in the Drainage 



CONTACT ( S ) ; Glenn Phillips - Montana Department of Fish, Wild- 

 life and Parks, Helena - 444-2406 



OBJECTIVE : To evaluate the toxicity of Clark Fork River water 

 during runoff season at various locations in the drainage. 



DURATION ; April, 1986 - completion of study 



CURRENT STATUS ; Fingerling rainbow trout were maintained for 

 two months (beginning in late April) in floating holding con- 

 tainers at seven locations in the Clark Fork River drainage. 

 Survival was monitored along with several chemical parameters 

 including total recoverable cooper, total recoverable zinc, al- 

 kalinity hardness, and pH. Flow measurements were also recorded 

 and loading of metals was estimated. 



FUTURE ACTIVITIES ; Spring runoff during 1986 was somewhat anom- 

 alous in that the river had experienced winter flooding in late 

 February. Winter flooding probably reduced metals loading in 

 the river during spring. Because of these unusual conditions, 

 the bioassays will be repeated during 1987. 



PUBLICATIONS AND REPORTS 



Preliminary data are available from the Montana Department of 

 Fish, Wildlife and Parks. 



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