8 Dec 2025

Assessing Fish-Passage Rates

Abstract: Riverine fragmentation by dams, culverts, and other barriers has led to the precipitous decline of migratory fishes nationwide. Accordingly, fish-passage restoration has emerged as a significant issue for resource agencies, restoration professionals, and fisheries managers. This special report addresses the key scientific challenge of measuring fish-passage rates before and after restoration. A variety of techniques for both forecasting (preproject) and monitoring (postproject) fish-passage rates are reviewed. A set of guiding questions are presented to help practitioners select a method appropriate to their site, resources, and time line. Four case studies are then presented to demonstrate a subset of these methods in practice: fish community movement through floodgate structures in Missouri, movement patterns through river restoration structures in Colorado, fish movement around a low-head weir in Mississippi, and watershed-wide passability estimation using professional judgment in Nevada. These projects represent a range of conditions and are intended to provide practitioners with real-world examples to use as models for their own studies.

8 Dec 2025

Modeling Tools for Proactive Ecosystem Restoration and Assisted Migration Planning: A State of the Science Review and Synthesis

Abstract: Decision-support modeling tools are needed to help aquatic ecosystem restoration (AER) planners understand how habitat footprints and species distributions will change in response to future changing conditions. Specifically, environmental projections and predictive model outputs that inform proactive AER planning and investments. This report provides a literature synthesis of resources and tools to create such a decision support tool. Select models identified were evaluated for applicability to AER planning using prediction confidence, user-friendliness, and suitability. This uncovered several existing, primarily terrestrially, predictive models that could be adapted to inform proactive AER planning efforts. Research efforts are still needed to fill gaps for aquatic data to train and validate predictive models, refine key drivers, and build and pilot aquatic-focused tools. Future condition vulnerability screening tools could be used to identify which proposed AER project sites are best suited for proactive AER measures, such as assisted migration, and determine if investments in more rigorous, spatially explicit, or species-specific models are needed. Species-specific assessments of habitat suitability changes and adaptive capacity can then inform restoration targets and enable end-users to achieve AER planning objectives. Such a decision support tool would improve planner ability to restore key aquatic habitats resilient to future conditions.

24 Nov 2025

3D Printing Natural Materials for Nature-Inspired Infrastructure— A Beneficial Use Opportunity: Collaborative Research Workshop Synthesis

Abstract: Natural infrastructure—crucial for coastal resilience, flood risk management, and ecosystem services—confronts escalating challenges from rising seas, erosion, storms, and human impacts. Innovative approaches are needed to enhance infrastructure functionality and broaden social, economic, and environmental benefits. Traditional manufacturing constrains engineering creativity required for nature-inspired infrastructure (NII). Additive manufacturing, or 3D printing (3DP), could revolutionize the design and functionality of NII. However, existing capability gaps hinder the effective transition of these technologies from conceptualization to implementation. Our workshop explored NII-3DP structures using natural materials, aligning with Engineering With Nature® (EWN®) principles and US Army Corps of Engineers infrastructure goals. Discussion included engineering solutions to provide social, recreational, environmental, and economic benefits, including flood risk reduction, wave energy dissipation, nutrient sequestration, and habitat enhancement. The participants sought to understand material selection and optimize morphologies to ensure the successful biocompatibility of nature-based habitats. By using locally sourced, biocompatible materials and drawing inspiration from nature, these technologies offer a means to enhance habitat function and improve aesthetics for communities. A timely opportunity exists to reshape the perception of locally available materials, such as sediment, by presenting dredged material as an environmentally and economically beneficial use asset and resource for 3DP feedstocks.

29 Oct 2025

Beneficial Use of Contaminated Sediments: A Review of Technical, Policy, and Regulatory Needs

Abstract: This special report summarizes key results from the March 2024 Sediment Management Working Group (SMWG) Contaminated Sediment Beneficial Use Workshop sponsored by US Army Engineer Research and Development Center’s (ERDC’s) Advanced Materials and Substances of Emerging Environmental Concern (AMSEEC) center, a multilaboratory research collaborative reviewing solutions to environmental challenges, and the Dredging Operations Environmental Research (DOER) Program, the navigational dredging research arm of ERDC. The workshop focused on potential avenues for treatment and management of contaminated sediments to support expanded beneficial use (BU) opportunities. AMSEEC, with support from DOER, sponsored four pilot studies to advance the technical aspects of the workshop program and partnered with the SMWG, an industry consortium, to organize the workshop in Washington, DC. The workshop was attended by more than 75 practitioners and relevant stakeholders to review these pilot studies and the challenges of advancing treatment and management of contaminated sediment to support BU. This special report summarizes and prioritizes technical, regulatory, and policy needs to enable expanded BU opportunities for contaminated sediments.

29 Oct 2025

A Multigenerational Exposure of the Zebrafish (Danio rerio) to PFOS

Abstract: The ecological risk of PFOS in extended chronic and multigenerational exposures was quantified through survival, growth, reproduction, and vitellogenin (egg yolk protein precursor) responses as well as PFOS bioconcentration in zebrafish (Danio rerio). Fish were exposed to environmentally relevant PFOS concentrations through 180 days postfertilization (dpf) in the parental (P) and first filial (F1) generations and 16 dpf in the second filial (F2) generation. Survival decreased significantly in P and F2 generation exposures, but not F1, at the highest PFOS treatment. Significant adverse effects on body weight and length occurred predominantly at highest exposure treatment. Finally, PFOS had no significant effects on P or F1 egg production and survival or whole-body vitellogenin levels in P or F1 male fish. The present investigation indicated a threshold for ecologically relevant adverse effects in zebrafish at 119 μg/L (standard deviation [S.D.] 23 μg/L, n = 10) for survival and 87 μg/L (S.D. 48 μg/L, n = 19) for all statistically significant negative effects observed. Importantly, males had significantly increased PFOS accumulation and bioconcentration factors versus females in both P and F1 generations. PFOS transfer to eggs was not a depuration pathway. Finally, a toxicokinetic model was developed to reliably predict PFOS whole-body burdens.

15 Oct 2025

An Investigation into the Correlation Between Selected Coastal Protection Indices and Percent Residual Dune and Berm Volumes Following Coastal Storms

Abstract: Morphometric indices describe the dimensions of a dune and berm profile and can serve as relative metrics of coastal protection. However, coastal vulnerability to storm damage also depends on storm, wave, sediment, and offshore characteristics. Recently, more elaborate non-morphometric indices have been proposed in an effort to account for these other factors. This study compares the correlation between these morphometric and non-morphometric indices and one measure of coastal protection, the ability of a dune and berm profile to resist storm-induced changes in volume. This study uses a numerical-simulation approach rather than an empirical approach because a sufficiently comprehensive set of observational data does not exist. A randomized sample of dune and berm profiles were generated at eight coastal locations. Using the cross-shore numerical model (CSHORE), storm-induced changes in dune and berm volume were simulated for storms of low to moderate severity. The correlation between the various prestorm indices and the percentage of prestorm dune and berm volume remaining after the storm was calculated at each location. Results show that no single index always exhibits a higher correlation with percent dune and berm volume remaining. However, some indices were far more likely than others to produce higher correlations.

7 Oct 2025

Gravel Investigations Informing Resource Management Within the Lower Mississippi River

Abstract: This report integrates available information about gravel deposits within the Lower Mississippi River (LMR) from previous studies coupled with new analysis to identify reoccurring observed gravel locations. This study also summarizes spatial and temporal trends of bed material sediment characteristics, focusing primarily on gravel. Moreover, selected data sets from previous studies, and field and aerial observations have been added to a geographic information system (GIS) database housed in ArcPro to illustrate observed gravel locations. Last, a literature review documenting the ecological importance of gravel bars to riverine fauna and a brief discussion of potential technologies to support conservation efforts are included. Major findings summarized herein are (1) the presence of gravel deposits tend to decrease in a downstream direction along the LMR; (2) qualitative analyses of aerial videos suggest that gravel-predominant bars are more common between River Miles 953 and 681; (3) past investigations have documented gravel sizes at rivers bars ranging from pebbles to boulders; (4) the gravel content in LMR bed material samples has decreased since 1932; and (5) more detailed surveys are needed to better delineate the spatial extents and depth of gravel bars and identify suitable technology to detect potential buried gravel.

1 Oct 2025

Relief Well Sustainment Deployable Resilient Installation Water Purification and Treatment System (RWS-DRIPS): Treatment of Relief Wells at Perry Dam, Kansas

Purpose: This report details the treatment process and resulting outcomes for relief wells at Perry Dam (Jefferson County, Kansas) using the Relief Well Sustainment Deployable Resilient Installation Water Purification and Treatment System (RWS-DRIPS) treatment trailer. The RWS-DRIPS is a mobile treatment unit with comprehensive water treatment capabilities designed to disinfect surface and subsurface water with high efficiency. Immediately following treatment with the RWS-DRIPS unit, video monitoring was used to observe the condition of the relief wells. The results of that observation are described in this report.

1 Oct 2025

Predicting Seagrass Habitat Suitability with Remote Sensing and Machine Learning: A Case Study in the Mississippi-Alabama Barrier Islands

Abstract: Seagrass occupies sandy platforms landward of the Mississippi-Alabama barrier islands, where the benthos experiences consistent sediment transport. This work characterized benthos surrounding Cat Island, Mississippi, to assess the influence of elevation and geomorphological features (e.g., slopes, flats, peaks, and valleys) on seagrass presence. Two machine learning algorithms predicted seagrass presence/absence (from airborne hyperspectral imagery) based on elevation and geomorphology (derived from airborne lidar bathymetry) for 2016, 2018, and 2019. Results indicated elevation primarily influenced seagrass presence, with minimal impact from geomorphology. Elevation change was not predictive, suggesting seagrass tolerated observed deposition/erosion rates. This research showcases remote sensing and machine learning efficacy in predicting seagrass habitat suitability (greater than 70% accuracy) and conveys implications for conservation.

30 Sep 2025

EWN Compass: Implementation Toolbox for Natural and Nature-Based Features

Purpose: This Engineering With Nature® (EWN®) technical note introduces the EWN Compass: Implementation Toolbox for Natural and Nature-Based Features—a user-friendly, web-based application developed using Esri ArcGIS Online. Designed to support practitioners in selecting and integrating natural and nature-based features (NNBF) into infrastructure projects, the toolbox provides structured access to existing resources, case studies, and environmental data to inform resilient and sustainable design solutions.