Migration Timing of a Threatened Smelt Species
Columbia River, Oregon and Washington
Port of Portland
Eulachon, a threatened smelt species, migrate from the ocean up the Columbia River and into select tributaries to spawn. However, the timing of this upstream migration is not well known and the state in-water work windows that were established to protect salmonids do not account for these recently listed fish. These unknowns have created questions about when in-water work, such as dredging and pile driving, should be conducted. To address these concerns, Hart Crowser has partnered with Oregon State University to implement a study using environmental DNA (eDNA) to investigate the timing of the eulachon migration. In 2015, 2016, and 2017, Hart Crowser biologists regularly sampled transects at crucial locations in the river for presence of eulachon DNA. These eDNA results were used to define the temporal and physical distribution of eulachon to support permitting and operations by the Port of Portland.