Reed College
Reed College

Primary Source Sets

Special Collections and Archives

Spawning and Migratory Habits of Columbia River Steelhead Trout as Determined by Scale Studies

Figures IV and V show steelhead trout scales. John B. Long, Reed College '36, investigated spawning habits and stream migration among steelhead trout in the Columbia River in his 1936 thesis. Long’s thesis was motivated by the recent damings of the Columbia River happening around the time of his project; at the time, there was little knowledge of the proportion of spawned steelhead that migrate back to the ocean. Long theorized that if large numbers typically make it back to the ocean, then accommodating measures should be taken with respect to the dams, and if not, accommodating measures were not necessary. Long found that 3.4 percent of the spawning steelhead trout in the Columbia River had spawning marks, which indicated that they had spawned before and were returning from the ocean to spawn again.

Item 9 of 10 in this set

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