Building on previously established methods, we propose to use existing PIT and active tag fish transit time and detection data to calibrate and validate a numerical 2D fish behavior model at Jones Beach. The resultant tool of this effort will be a probability-based heat map of detection locations with bounded levels of confidence for each existing pile dike location of interest. The work will be conducted by USACE researchers of the Portland District and the Engineering Research and Development Center who have recently applied the methodology with success on the Columbia River upstream of Jones Beach. Successful application of this modeling approach will result in a valuable tool for pile dike-based PIT array placement at Jones Beach and inform other aspects of fish detection technologies and fish response to pile dikes and associated navigation structures.  

BACKGROUND
    
Since 1987 PIT tags have been used to tag fish for a variety of BPA and USACE monitoring programs and research studies on the Columbia River. The PIT tags and detection systems have been a vital tool for evaluating USACE facilities, juvenile travel time, juvenile transportation programs, overall system survival, and guidance of hydrosystem operations (2020 CRS BiOp). Each year, modeling is used to estimate the expected hydro-system in-river benefits from dam modifications. The modeling estimates for survival through different reaches are also compared to empirical PIT tag based in-¬river survival estimates. Various off-site systems, some operational and others in development, are used to supplement PIT detections at dams. Data collected by these off-site arrays are critical for making the empirical PIT-based survival estimates through different reaches.  As of 2024, these “off-site” arrays have included:

o    PIT trawl detection system near Jones Beach, Columbia River
o    Pile dike arrays near Jones Beach, Columbia River
o    Flexible array near Jones Beach, Columbia River
o    Experimental PIT barge(s), varying location(s)

In 2011, NOAA started using pile dike-based PIT arrays for juvenile and adult salmon detection and discovered that such arrays could increase detection efficiencies while decreasing the program’s expense (Magie et al. 2013). What started as an adult fish PIT detection system was ultimately focused on juvenile fish systems to better achieve the objectives of the monitoring program (Magie et al. 2015). Ten years of data collection from boat-based and pile dike-based PIT tag array manipulation has fine-tuned the systems to detect juvenile salmon and determined that some arrays detect more fish than others (Brooks 2024, Figure 1). In 2023, NOAA installed additional arrays, like Pile Dike 8, upstream of the existing arrays in the Jones Beach study area. Site selection for the array was based on anecdotal information that suggested juvenile fish might be at the site. These indicators included concentrations of foraging piscivorous birds and accumulation of debris near the pile dike system (G. Brooks. Pers. Comm). Operation of the Pile Dike 8 array in 2023 yielded discouraging results with an order-of-magnitude less tags detected at the site than the other pile dike arrays operated immediately downstream. Such results necessitate a better system of site selection to optimize the tag detection and increase the return on investment.
Herein, we propose a modeling approach that will integrate existing hydrodynamic based 2-D fish behavior models with the existing Jones Beach PIT detection data to inform where new pile dike-based PIT arrays should be placed. Using an established salmon-based mechanistic behavior modeling technique derived from the Eulerian-Langrangian-Agent-Method (ELAM) to define and prescribe behaviors of fish particles in a theoretical riverine space (Goodwin et al. 2006, Goodwin et al. 2023); the Jones Beach study area can be modeled with ELAM fish particles measured in a high definition 2-D Adaptive Hydraulics (AdH) model that enumerates and defines the hydraulic behaviors of the river (Pevey et al. 2012). A recent application of this approach with tagged juvenile salmon responding to proposed pile dike structures provided evidence that the model produces valuable data that can be used to predict fish migration path, transit time, and responses to proposed navigation structures (Tidwell and Smith, In Prep).