Klamath River renewal project molecular library

The Klamath River Renewal Project (KRRP) is a large dam removal and river
restoration project in California and Oregon, United States. With the
removal of four large dams in 2024, restoration of connectivity to 640
river kilometers occurred. We created the KRRP molecular library, an
environmental specimen bank, for long-term curation of environmental
nucleic acids collected from the restoration project area. The library
established sampling stations from 45 main stem and tributary sites, as
well as pre-dam removal water samples preserved for environmental nucleic
acids (eDNA and eRNA) intended to provide long-term use of both raw and
extracted molecular material used to track the ecosystem response to dam
removal. On a subset of samples, we conducted DNA metabarcoding using next
generation sequencing based on the MiFish-U and modified MiFish-U-F primer
sets. We used sequence reads to visualize data and calculate diversity
metrics to establish a pre-dam removal baseline and proof of concept that
the molecular techniques could resolve changes to fish and other aquatic
organisms resulting from short- and long-term changes due to dam removal.
These and future sampling efforts should, at a minimum, allow tracking of
fish community response to ecosystem restoration.