Research and Development Office

Quantifying Fish Biomass X Distance from Environmental DNA Samples in a Hydrodynamically Complex Environment

Project ID: 19225
Principal Investigator: Andrew Schultz
Research Topic: Fish Passage and Entrainment
Funded Fiscal Years: 2019, 2020 and 2021
Keywords: None

Research Question

Can monitoring of Environmental DNA (eDNA) in hydraulically dynamic systems be used as a tool for monitoring target species to facilitate optimization of water delivery operations? Our specific research question will investigate how much fish biomass X distance is present when a quantity of DNA is obtained in a water sample. It is not possible to calculate the biomass alone because an infinite number of combinations of fish biomass and distance could produce the same amount of DNA in a water sample. Thus it is necessary to calculate the biomass X distance.
It is hypothesized that the quantity of target-fish DNA in a water sample will increase with fish biomass but will decrease with distance of that biomass from the sampling location. Furthermore, it is hypothesized that the deterioration rate of DNA in a linear water body (e.g., Lindsey Slough [Solano County, CA]) will occur at an exponential rate affected by temperature (Eichmiller et al., 2016) and ultraviolet (UV) radiation in the water column.

Need and Benefit

In the FY2019 Science Strategy Implementation Plan (USBR 2018) the description of Water Supply Reliability is
stated: "Improve the reliability of Reclamation water supplies by finding innovative means to address aquatic and
terrestrial ecosystem and species needs while still meeting water delivery contracts."
The emerging field of environmental DNA (eDNA) is an innovative means to address an old problem facing
Reclamation: when can we maximize water deliveries to meet water delivery contracts? Water delivery is often
curtailed because certain regulatory criteria are met. For example, flows in the Old and Middle Rivers (OMR),
California, are used to determine when to reduce exports. NMFS (2009, pgs. 648-650) Biological Opinion requires
(Action IV.2.3) "Reduced exports to limit negative flows in OMR depending on presence of salmonids." The "presence
of salmonids" is determined by salvaged salmonid juveniles. If this study is funded, we will develop a method for
determining if listed salmonids are actually approaching the diversion BEFORE they are in the facility and thus would
never be salvaged. Water deliveries can be made consistently when no listed fish are present because this study will
provide a tool to show definitively that no listed fish are approaching the diversion.
Not funding this research will delay meeting the inevitable need to identify better methods to monitor target species
for optimization of water deliveries.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Quantifying Fish Biomass X Distance from Environmental DNA Samples in a Hydrodynamically Complex Environment (final, PDF, 1.9MB)
By B. Mahardja, A.A. Schultz, M. Johnston, S.M. Blankenship, M.B. Espe, G. Schumer, M.D. Bowen, C.A. Dean, K. Karpenko, M. Brennan and C. Hart
Report completed on September 30, 2021

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