Water samples collected during the years 1969 through 1972, from 36 selected Alaskan rivers were analyzed for dissolved oxygen, pH, conductivity and alkalinity. Dissolved oxygen (D.O.) ranged from 0.0 to 15.3 ml/l (106 percent saturation); pH from 6.2 to 8.4; conductivity varied from 105 to 3000 (umho/cm); and alkalinity from 28 to 410 (mg/l). Severe D.O. depletion during winter was found in many river systems large and small, and located in a range of latitudes (70 degrees N to 61 degrees N). Sufficient data were collected on the Chena, Chatanika, and Salcha Rivers to reveal annual D.O. trends. The depressed winter D.O. concentrations and low winter discharge in many Alaskan rivers are more severe and widespread than present literature indicates. Winter conditions may already limit aquatic organisms in some systems.

"April 1974." "Prepared for National Environmental Research Center, Office of Research and Development, U.S. Environmental Protection Agency." Authors affiliated with Arctic Environmental Research Laboratory, College, Alaska. "Project 21ARX, Program Element 1BA021." Includes bibliographical references (pages 31-33).