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Sather, Nichole K.

Publications and source records attributed to Sather, Nichole K..

Juvenile Salmon and Their Habitats in the Columbia River Estuary: A Review and Synthesis of Knowledge Development 2000–2025

[This is a 90% discussion draft.] This is the third Synthesis Memorandum funded by the U.S. Army Corps of Engineers and developed for the Columbia Estuary Ecosystem Restoration Program (CEERP) on the topic of habitat restoration in the Columbia River Estuary (CRE) from Bonneville Dam to the river mouth. While the first two were developed by PNNL and NOAA without the benefit of stakeholder participation, for the current memo, two key activities were initiated: (1) review, by the Expert Regional Technical Group (ERTG), of status and trends monitoring and action effectiveness monitoring funded by CEERP, and (2) a workshop including representatives of the Bonneville Power Administration and the U.S. Army Corps of Engineers (the action agencies [AAs]), the National Oceanic and Atmospheric Administration (NOAA), major research agencies contributing to CEERP, and sponsors who implement CEERP restoration actions. A systematic literature review was conducted using ClarivateTM Web of ScienceTM database. The topics of interest for CRE relevant research included salmon ecology, physical processes, and wetland habitats, and therefore required the use of broad search terms. Our final search criteria included a combination of Boolean operators and an approach to combine different sets of search terms. The final search result yielded 669 records. The records were classified by groups and assigned to the relevant disciplinary expert for review. The review identified substantive advances in understanding the provision of salmon habitat functions through spatiotemporally dynamic physical and ecological processes, and the use of CRE habitats by numerous stocks of juvenile salmon. It also uncovered heretofore unincorporated historical documentation of riparian habitats across the CRE. The characterization of the structural components of floodplain habitat including plant associations and channel networks has advanced considerably, together with the understanding of seasonal changes and long-term trends. The relative influence of salmon-habitat location in the CRE as compared with temporal factors, mainly season, has been well described, which affects the prioritization of restoration. Stressors on the ecosystem and fish, and the drivers of these stressors, have been more carefully elucidated and predictive models are in various stages of development. The vision, aims, and design of restoration projects have advanced together with methods of data collection, analysis, and modeling that have seen substantial improvements. Experiments intended to inform the design of restoration projects are underway or have been completed. An important outstanding area of research that has lagged behind the advances in fundamental understanding of the ecosystem and salmon habitat functions remains the peer-reviewed documentation of the outcomes of restoration for both habitats and fish functions.

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CEERP SM3 Research, Monitoring, and Evaluation Workshop: Summary Report

The Columbia Estuary Ecosystem Restoration Program (CEERP) workshop, “CEERP Synthesis Memorandum (SM3): Research, Monitoring, and Evaluation,” was held in Portland, Oregon on June 24–25 2024. A diverse group of 26 domain experts with demonstrated knowledge and experience working in the Lower Columbia River Estuary (LCRE) participated. The workshop supported development of the forthcoming third Synthesis Memorandum for CEERP. The workshop furthered the collaborative understanding of the state of the science regarding the LCRE, helped to identify remaining knowledge gaps and uncertainties, and assisted in the prioritization of future restoration research and monitoring.

54 ENVIRONMENTAL SCIENCES↗

TEAMER - Field Demonstration of MarineSitu’s Marine Energy Monitoring Tools - CRADA 664 (Abstract)

In order to effectively monitor for marine life around marine energy devices and thus minimize the risk of collision, multiple sensors working in coordination and augmented with around-the-clock automated monitoring algorithms need to be installed in challenging high-energy tidal and wave environments. Such systems are often too expensive for widespread adoption, or lack sufficient sensors or smarts to enable around-the-clock, real-time monitoring without human involvement. MarineSitu has been working to tackle this problem by developing a low-cost, combined sonar and stereo camera sensor array with connected real-time AI-based algorithms for automatically detecting marine life in these marine energy suitable environments. In this TEAMER project with Pacific Northwest National Lab (PNNL), MarineSitu will be testing this novel sensor system for the first time in the high-energy tidal channel environment at PNNL’s Marine and Coastal Research Lab. Throughout this deployment, MarineSitu will be monitoring their system and running analytics on the sensor’s data in real-time. Meanwhile, PNNL Data Scientists and Ocean Engineers, will be evaluating the system’s effectiveness and ease of use both as a tool for plug-and-play environmental monitoring and novel environmental monitoring research. In doing so, the team will improve MarineSitu’s system and software, produce insightful data products, and develop novel visualizations and AI algorithms for combining and analyzing the data produced by systems like MarineSitu’s.

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Action Effectiveness Monitoring and Research of Dredged Material Placement at Woodland Islands (Final Report)

Benthic invertebrates play critical ecosystem roles including the breakdown of organic matter, sediment mixing, and nutrient cycling. In the lower Columbia River and estuary, benthic invertebrates provide a foraging resource for threatened and endangered juvenile salmon. Driven by the goal to create low velocity, shallow water, and riparian shrub habitats to benefit juvenile salmon, the USACE placed 237,000 CY of dredged material, resulting in the deposition of 13.5 acres of sand on the off-channel margins at Woodland Islands. The Pacific Northwest National Laboratory (PNNL) designed and implemented an action effectiveness research study to understand how dredged material placement at Woodland Islands affected sediment conditions and benthic invertebrate assemblages. A Before-After-Control-Impact, or BACI, study design was used to evaluate the response of environmental conditions and benthic invertebrates to dredged material placement. The design included one impact site and two control sites. Sampling occurred for two years prior to dredged material placement and two years after. Our study found that spatial variation was a significant factor for both environmental and biological response variables which suggests local conditions are important considerations for mechanisms affecting benthic assemblages. We found that off-channel habitats across all locations sampled were producing benthic invertebrates, many of which are common prey items for juvenile salmon and steelhead—e.g., insects, chironomids, crustaceans, and corophium. There was a significant BACI effect (i.e., an effect at the dredged material placement site, relative to conditions at the control sites) for concentration of carbon and ammonium in sediment, but not for phosphorous concentrations or for percent sand. The estimated abundance for the three invertebrate response variables—total abundance, total chironomid abundance, and total corophium abundance—was significantly lower at the impact site after dredged material placement, compared to the control sites. At Woodland Island, the estimated mean abundance for all invertebrates combined decreased 28% after dredged material placement. Estimated mean abundances of chironomid and corophium decreased by 8% and 88%, respectively. While invertebrate abundances were lower after dredged placement, the composition of benthic invertebrates was similar before and after placement suggesting that as the new habitat feature evolves recolonization will likely follow. These findings provide a foundation for understanding potential benefits and consequences of repurposing dredged material for habitat creation in the LCRE.

54 ENVIRONMENTAL SCIENCES↗

Post Access Report: Initial testing of wave energy powered UV-C LED anti-biofouling system

In the experiment entitled “Initial Testing of Wave Energy Powered UV-C LED Anti-Biofouling System,” a UV-C LED was used to treat platinum-coated titanium coupons emulating CTD electrode material. An additional control set of coupons were exposed to seawater without the LED treatment. The experimental setup was deployed in seawater tanks at PNNL-Sequim’s Marine and Coastal Research Laboratory (MCRL) for the duration of six months. Tank seawater temperature data were collected for the duration of the experimental campaign. At two-month intervals triplicate sets of coupons were removed from both treatment and control test chambers and weighed to characterize biomass accumulation. After weighing, the coupons were photographed in initial condition, with a stain applied to highlight biofouling growth, and after rinsing off excess stain. These photographs were analyzed using PNNL’s Biofouling Growth Index (BGI) software and with a calculation of percentage dark pixels after conversion to grayscale. Additionally, at the final 6-month datapoint triplicate sets of control and test coupons were sent to PNNL-Richland’s Environmental Molecular Sciences Laboratory (EMSL) for scanning electron microscopy. All data organization and collection methods are described in further detail in the document “TEAMER_3newable_Data_Guide.pdf.” Biomass accumulation increased over time on both sets of coupons, and percent area biofouled demonstrated a similar trend. Analysis of the collected data resulted in the findings that treatment method has an impact on biofouling growth, though to a much less significant extent than time does. Additionally, qualitative findings included the presence of advanced life forms such as worms in the control test chamber, but not in the treated test chamber.

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TEAMER - Acoustic Particle Velocity Measurements - CRADA 601 (Abstract)

With relatively few deployments of tidal turbines, the extent and effect of underwater sounds generated from these turbines is not well understood. The University of Washington (UW) is deploying a cross-flow turbine system, the Turbine Lander, in the entrance channel to Sequim Bay. The deployment of this system provides an opportunity to understand the noise radiated by the turbine and its sources. There are three hypothesized sound sources associated with operation of the turbine: 1) a continuous tone associated with energized power electronics; 2) sound associated with the generator when the turbine is rotating; and 3) sound associated with the bearing pack that supports the rotor. PNNL is collaborating with UW and Integral Consulting Inc. (Integral) to simultaneously measure sound sources using three different devices. The NoiseSpotter®, an acoustic sensor system designed by Integral, measures acoustic pressure and a three-dimensional particle velocity vector. The NoiseSpotter, along with a commercial-off-the-shelf acoustic particle motion and pressure sensor (M20-105, Geospectrum Technologies Inc.) owned by PNNL will be deployed on the seabed approximately 50-100 m from the Turbine Lander. UW will concurrently deploy Drifting Acoustic Instrumentation SYstems (DAISYs) to characterize acoustic pressure near the Turbine Lander and localize sounds using a Time Delay of Arrival (TDOA) algorithm. Integral, UW, and PNNL will collaborate on data analysis and interpretation, with the intention of jointly authoring an archival paper on the results. The noise generated from the Turbine Lander is not expected to be significant, yet this experiment will help to evaluate the efficacy of combining technologies to characterize noise and provide insights for approaches to consider for future turbine deployments at other locations.

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TEAMER: DAISY Flow-noise Testing (Abstract)

Evaluating impacts of marine energy devices is generally difficult given the dynamic environment where these devices need to be placed. The University of Washington’s (UW) DAISY (The Drifting Acoustic Instrumentation SYstem) is designed to measure radiated noise around marine energy converters operating in energetic waves and currents. In currents, a primary limitation for measurement fidelity at low frequencies (< 100 Hz) is the potential for non-propagating “flow-noise” to mask propagating sound and inflate estimates of the radiated noise from marine energy converters at frequencies that overlap with hearing sensitivities of fish and some marine mammals. While free-drifting measurements help to minimize the relative velocity that produces flow-noise, significant levels were still observed during initial DAISY tests. This motivated the development of a fabric “flow shield” around the hydrophone that disrupts both flow-noise generation mechanisms proposed by the initial tests. First, the flow shield is a source of substantial drag which keeps the hydrophone package moving with the approximate velocity of the surrounding water, compensating for differential wind or current forcing on the surface expression. By minimizing relative velocity around the hydrophone, turbulence shed by the hydrophone is also minimized. Second, the flow shield creates a largely quiescent pocket around the hydrophone, minimizing advection of free stream turbulence over the hydrophone element. Field data collected in these experiments will test effectiveness of these flow shields and provide quantitative data use and deployment.

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San Juan Islands Tidal Energy Characterization

The San Juan Islands are an archipelago with multiple tidal channels that produce strong tidal currents that could be harnessed for electricity generation. At present, there is limited electrical generation on the islands, with power primarily provided by a subsea cable connection with the mainland. As part of the C-MIST program, NOAA's CO-OPS program collected ADCP data at 46 stations in the San Juan Islands and adjacent waterways, from April to August of 2017. PNNL has recently developed a 3-D tidal hydrodynamic model for tidal energy resource characterization and assessment in the Salish Sea (Yang et al. 2021). Several tidal channels in the San Juan Islands were identified as top hotspots for potential tidal energy extraction. However, due to the complex geometry and inter-connected waterways, tidal currents around San Juan Islands also exhibit strong spatial and temporal asymmetry. Therefore, it is important to analyze the NOAA ADCP data to define metrics relevant to tidal energy, and further refine PNNL's tidal hydrodynamic model to accurately simulate currents in small tidal channels and account for sharp bathymetry gradients. The outcome of this technical assistance will allow developers to identify the promising opportunities for tidal energy in the San Juan Islands.

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