OXYGEN BLOCK IN THE 



MAIN -STEM WILLAMETTE RIVER 



i.iiit' I'.iological Labordtory 



B R A tl Y 



OCT 9-1950 



WOODS HOLE. MASS. 



SPECIAL SCIENTIFIC REPORT: FISHERIES No. 41 



UNITED STATES DEPARTMENT OF THE INTERIOR 

 FISH AND WILDLIFE SERVICE 



