Recolonization of Coho Salmon on the Klamath River Above the Iron Gate Dam (2018 – $1,500)
Humboldt State University
California’s anadromous fish populations are increasingly threatened by climate change, increased agriculture activity, infrastructure development, and habitat degradation. Dam removal has become an important riverine habitat restoration technique. Major dams installed as part of the Klamath Hydroelectric Project (KHP) have influenced the Klamath River watershed and its anadromous fisheries. Four major dams (Iron Gate, Copco 1 & 2, and J.C. Boyle) block all fish passage past 190 river miles. Historically, four anadromous fish species (coho salmon, Chinook salmon, steelhead trout, and Pacific lamprey) utilized habitat above the KHP. Dam removal slated for 2020 will restore access to critical habitat for all four of these anadromous fish populations. In anticipation of dam removal, my project will assess the three largest Klamath River tributaries in California upstream of the dams as well as one reference tributary below the dam (Dry Creek) representative of unrestricted anadromous fish movement. My project has two primary objectives: 1) Assess the potential of these streams to support the return of coho salmon (Oncorhynchus kisutch). 2) Provide the baseline data necessary for determining the impact of anadromous fishes on resident species richness and abundance in tributary systems.
My project will collect spatially continuous information on riverine habitat and fish populations with an emphasis on invertebrate and vertebrate assemblages from four tributaries (Jenny Creek, Fall Creek, Shovel Creek, and Dry Creek) to the Klamath River. I will use habitat models to predict the juvenile rearing abundance of coho salmon in the tributaries above the dams. In addition, I will measure fish community diversity, abundance of residence fish, and growth rates of resident fish in order to provide a baseline so that we can determine if these factors change after dams are removed and anadromous fish recolonize these tributaries.
Longitudinal surveys of fish species and aquatic habitat will be conducted for each of the three study tributaries. Longitudinal fish surveys will consist of spatially continuous snorkel surveys from the tributary mouth to 500 meters upstream of the anadromous fish barrier (4.45 km, 3.2 km, and 3.3 km for Shovel, Fall, and Jenny creeks respectively). Snorkel surveys will be conducted in 100 meter reaches by a survey crew of two trained individuals. Snorkel surveys will observe and record all fish species by length class. Longitudinal habitat surveys will be conducted following snorkel surveys, using a standardized habitat sampling protocol. Habitat surveys will measure habitat type, channel type, wetted width, cover type, and substrate type. Benthic macroinvertebrate sampling will be conducted post snorkel and habitat surveys. Benthic macroinvertebrate sampling will consist of 10 samples per reach, targeting a riffle habitat supportive to the diversity of the macroinvertebrate assemblage in stream ecosystems. During the spring of 2018, sampling protocol and hard sampling dates will be determined for the summer 2018 field season. A preliminary site visit will be conducted in the early spring of 2018. HOBO thermos-loggers will be installed in late spring 2018 at locations representative of the study and reference reaches. Sampling events will begin in early summer 2018. Analysis and data exploration will take place in the Fall of 2018. Research article, poster design and presentation will be completed in the winter of 2019.
Success of the project will be assessed by five primary outcomes. A poster will be designed and printed highlighting project methods and results for display on the HSU campus and fisheries conferences. A formal presentation will be created and presented to the Cal-Neva chapter of the American Fisheries Society in the winter of 2019. Undergraduate student, graduate student as well as Humboldt county community member field volunteer opportunities will be provided via flyers and networking during the summer of 2018. A final research article based on my summers research will be produced and published in a scientific journal. All data collected and explored will be utilized in my master’s thesis at HSU.