Temperature Tolerance of Eggs and Young of Columbia River Chinook Salmon

Abstract

A study was made on the temperature tolerance of eggs and young of chinook salmon which spawn in the main stem of the Columbia River. The control temperature followed a seasonal trend typical for the locality. It started at 57°F., reached a minimum of 36°F., and increased to 47°F. at the end of the test. Other experimental lots averaged about 4°F. colder and 2°F., 4°F., and 8°F. warmer than the control throughout the greater part of the test.

Significant mortality above that of the control occurred only in the warmest lot. Although about 90 percent of the eggs in this group hatched successfully, the fry and early fingerlings suffered heavy mortalities even though the mean temperature of this lot was well below 50°F. during the fingerling stage.

The results of this single experiment indicated that the eggs could begin incubation at temperatures as high as 61°F. without significant loss.