Characterizing the distribution of an endangered salmonid using environmental DNA analysis

Biological Conservation
By: , and 



Determining species distributions accurately is crucial to developing conservation and management strategies for imperiled species, but a challenging task for small populations. We evaluated the efficacy of environmental DNA (eDNA) analysis for improving detection and thus potentially refining the known distribution of Chinook salmon (Oncorhynchus tshawytscha) in the Methow and Okanogan Subbasins of the Upper Columbia River, which span the border between Washington, USA and British Columbia, Canada. We developed an assay to target a 90 base pair sequence of Chinook DNA and used quantitative polymerase chain reaction (qPCR) to quantify the amount of Chinook eDNA in triplicate 1-L water samples collected at 48 stream locations in June and again in August 2012. The overall probability of detecting Chinook with our eDNA method in areas within the known distribution was 0.77 (±0.05 SE). Detection probability was lower in June (0.62, ±0.08 SE) during high flows and at the beginning of spring Chinook migration than during base flows in August (0.93, ±0.04 SE). In the Methow subbasin, mean eDNA concentration was higher in August compared to June, especially in smaller tributaries, probably resulting from the arrival of spring Chinook adults, reduced discharge, or both. Chinook eDNA concentrations did not appear to change in the Okanogan subbasin from June to August. Contrary to our expectations about downstream eDNA accumulation, Chinook eDNA did not decrease in concentration in upstream reaches (0–120 km). Further examination of factors influencing spatial distribution of eDNA in lotic systems may allow for greater inference of local population densities along stream networks or watersheds. These results demonstrate the potential effectiveness of eDNA detection methods for determining landscape-level distribution of anadromous salmonids in large river systems.

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Publication type Article
Publication Subtype Journal Article
Title Characterizing the distribution of an endangered salmonid using environmental DNA analysis
Series title Biological Conservation
DOI 10.1016/j.biocon.2014.11.025
Volume 183
Year Published 2015
Language English
Publisher Elsevier
Contributing office(s) Forest and Rangeland Ecosystem Science Center
Description 9 p.
First page 29
Last page 37
Public Comments Special Issue: Environmental DNA: A powerful new tool for biological conservation
Country Canada, United States
State British Columbia, Washington
Other Geospatial Upper Columbia River
Online Only (Y/N) N
Additional Online Files (Y/N) N
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