Transportation agencies are frequently required to conduct analyses of the biological elements of ecosystems as part of their work in constructing and repairing roads and culverts. However, measuring ecosystems\u2014and particularly the impacts of construction projects on those ecosystems\u2014is not a straightforward or standardized process. The goal of this project was to demonstrate a widely applicable, rigorous, quantitative method for reporting on environmental impact using environmental DNA.<\/p>\n\n\n\n
Environmental impact assessment is notoriously time-consuming, expensive, and imprecise in its conclusions. However, amplicon-sequencing\u2014also called metabarcoding\u2014of environmental DNA (eDNA) has made it possible to sample and amplify the genetic material of many species present in the environment. This provides a tractable, powerful, and increasingly common way of conducting environmental impact analysis for development projects.<\/p>\n\n\n\n
To test this approach, the researchers analyzed an 18-month time-series of water samples taken before, during, and after two WSDOT culvert replacements in a salmonid-bearing freshwater stream. WSDOT began construction in April 2021 to replace two sloping culverts along 2.7 miles of Padden Creek between Padden Lake and Bellingham Bay, Washington. The researchers also sampled four nearby control streams to collect background data against which to compare the impact of the culvert replacements. They generated calibrated, quantitative metabarcoding data to yield multi-species estimates of eDNA concentrations across time, creeks, and sampling stations. Modeling revealed patterns of eDNA concentrations over time and estimations of the effects of the culvert replacements on salmonids in the treatment creek.<\/p>\n\n\n\n
The researchers focused the analysis on four common salmonid species: cutthroat trout (Oncorhynchus clarkii<\/em>), coho salmon (O. kisutch<\/em>), rainbow trout (O. mykiss<\/em>), and sockeye salmon (O. nerka<\/em>). They found that in the treatment creek and control sites, four of the six barriers did not prohibit salmonid passage. Of the two culvert replacements in the treatment creek, they found that one seemed to have no impact on fish passage whereas the second culvert had a large impact. However, both had minimal impacts on the four salmonid species monitored over the course of construction.<\/p>\n\n\n\n The project also provided a framework in which metabarcoding data can be linked with quantitative polymerase chain reaction (qPCR) data to obtain quantitative estimates of eDNA concentrations of many species. This provides a practical way to utilize the large amount of information from metabarcoding data without the need for a unique qPCR assay for every species of interest.<\/p>\n\n\n\n The researchers concluded that in the context of billions of dollars of court-mandated road culvert replacements occurring in Washington state, culvert replacement construction can be conducted with only minimal impact on key species of concern. Furthermore, eDNA methods can be an effective and efficient approach for monitoring hundreds of culverts and prioritizing those that must be replaced. The study also demonstrated that eDNA can be broadly used for environmental impact assessments for a wide range of species and environments.<\/p>\n\n\n\n Report: WA-RD 927.1<\/a><\/p>\n\n\n\n Authors: Sponsor: WSDOT WSDOT Project Manager: Jon Peterson<\/p>\n","protected":false},"excerpt":{"rendered":" Transportation agencies are frequently required to conduct analyses of the biological elements of ecosystems as part of their work in constructing and repairing roads and culverts. However, measuring ecosystems\u2014and particularly the impacts of construction projects on those ecosystems\u2014is not a straightforward or standardized process. The goal of this project was to demonstrate a widely applicable, rigorous, quantitative method for reporting on environmental impact using environmental DNA.<\/p>\n","protected":false},"author":1,"featured_media":9940,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3,42],"tags":[],"class_list":["post-9937","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-environment","category-research-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/posts\/9937","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/comments?post=9937"}],"version-history":[{"count":1,"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/posts\/9937\/revisions"}],"predecessor-version":[{"id":9939,"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/posts\/9937\/revisions\/9939"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/media\/9940"}],"wp:attachment":[{"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/media?parent=9937"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/categories?post=9937"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/depts.washington.edu\/trac\/wp-json\/wp\/v2\/tags?post=9937"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
Ryan P. Kelly<\/a>
Elizabeth A. Allan
Erin D\u2019Agnese
Maya Garber-Yonts
UW School of Marine and Environmental Affairs<\/p>\n\n\n\n
WSDOT Technical Monitors:
Susan Kanzler<\/a>
Tammy Schmidt<\/a><\/p>\n\n\n\n