5 Jun 2026

Environmental DNA Metabarcoding Elucidates Freshwater Mussel Diversity and Occupancy to Facilitate Improved Management and Conservation

Abstract: Freshwater mussels are considered among the most at-risk taxa in the world. As such, comprehensive monitoring assessments of what abiotic and biotic factors influence mussel occupancy will be vital for guiding effective conservation. Here, we analysed vertebrate and mussel environmental DNA metabarcoding data to explore the influence of biotic and abiotic factors on freshwater mussel populations. This study utilised water samples and tactile survey data collected from streams throughout Fort Johnson, Louisiana. Methods: We first evaluated the effectiveness of eDNA metabarcoding for characterising freshwater communities based on previous conventional tactile surveys. Next, we used eDNA metabarcoding analysis for freshwater mussels and vertebrate species alongside GIS-derived satellite remote sensing data to assess how various biotic and abiotic variables impact freshwater mussel eDNA occupancy. Our eDNA metabarcoding survey largely agreed with both historical and contemporary surveys on Fort Johnson, while uniquely detecting Louisiana pigtoe, a proposed threatened species under the US Endangered Species Act. We also found that eDNA detections and occupancy had strong seasonal variation, with increased read abundance and diversity in the spring. Vertebrate, fish, and predator diversity were strongly predictive of mussel occupancy, supporting the concept of land managers focusing on the entire ecosystem for mussel conservation. Lastly, we found that percent forest cover and drainage basin size influenced mussel eDNA occupancy, informing habitat associations for mussel species of interest. Our results demonstrate that combining eDNA metabarcoding of target and non- target species with occupancy modelling can provide insights into the ecology of freshwater mussels and is a useful tool to improve their conservation and management.

5 Jun 2026

Multitemporal Change Detection in the Coastal Zone: Literature Review

Abstract: Beach volume change is a primary metric for quantifying coastal change due to physical and anthropogenic forces. Volumes provide key inputs for the creation and maintenance of regional sediment budgets that inform engineering decisions and ensure the effective management of sediment. This special report provides a comprehensive literature review of the state of the art for developing beach volume change metrics, including methods, software and tools, and common sources of error. The reviewed literature indicates that common proxy-based methods for developing volumes (e.g., shoreline change analysis and beach profile change analysis) are limited in their applicability for study areas with alongshore geomorphic variability. A digital elevation model (DEM) of difference method used with high-resolution (e.g., 1 m DEM) datasets captures volumes over spatially variable geomorphologies more accurately; however, the literature notes limitations related to elevation dataset coverage and geometries used for aggregating volume quantities. Space-time cube methods enable cell-by-cell comparisons of volumes over multiple time periods within defined neighborhoods and provide additional insights, efficiencies, and flexibilities to afore-mentioned methods. A new beach volume framework is required to address limitations related to geomorphic variability, aggregation units, and dataset coverage.

4 Jun 2026

Brief Overview and Guide to Developing Monitoring and Adaptive Management Plans

Purpose: The purpose of this technical note is to summarizes key points on monitoring and adaptive management from the more detailed US Army Corps of Engineers (USACE) report ERDC/EL SR-19-9, “A Systems Approach to Ecosystem Adaptive Management: A USACE Technical Guide” and to provide a quick guide to developing monitoring and adaptive management plans (MAMPs) relevant to ecosystem restoration and mitigation projects. Although this report was written specifically for USACE projects, it is applicable to most restoration and mitigation projects. This guide does not supersede current or future USACE policy or guidance, nor is it applicable to private mitigation projects regulated by USACE.

4 Jun 2026

PFAS Interactions with ASTM Fat Clay and ASTM Ottawa Sand: Implications for Contamination from High-Concentration PFAS Sources Using Fourier Transform Infrared (FTIR) Spectroscopy

Purpose: This technical note seeks to understand the impact of high per- and polyfluoroalkyl substances (PFAS) concentrations on soils, specifically fat clay and Ottawa F-65 sand. This technical note also aims to understand the absorption and retention behaviors of PFAS in these two soil types and how the behaviors may vary because of the soil’s distinct properties.

4 Jun 2026

Efficacy of UVC Treatment on Hydrilla verticillata and Trapa spp.

Abstract: Hydrilla verticillata and Trapa spp. are invasive aquatic plants that pose serious challenges to freshwater ecosystems. In search of a nonchemical method to eradicate H. verticillata and Trapa spp., this study explores the application of UVC light to target the adult plant forms and the dormant turions of H. verticillata as well as the seedlings of Trapa spp. Contrary to our expectations, the experimental results demonstrated that UVC exposure had no significant effect on reducing the viability of either adult hydrilla plants or their turions. Despite treatment with a range of UVC doses, the plants remained viable and the turions were able to germinate successfully. UVC exposure did, however, cause a significant reduction in biomass for both Trapa species tested. These findings suggest that UVC light, at least under the conditions tested, is not an effective standalone strategy for controlling hydrilla but may be a useful nonchemical tool for controlling Trapa spp. Further research is required to explore alternative nonchemical methods or to refine the application parameters of UVC if it is to be further considered for eradication of these two invasive aquatic plants

1 Jun 2026

Operational Analysis of Composting for Military Installation Resilience

Abstract: On military installations, food waste is the heaviest portion of solid waste. At a single installation, food waste and its management can contribute up to $1.5 million lost annually. Additionally, Army installations pay over $100 million annually in disposal fees. Army policy calls for source reduction and composting as preferred methods of waste management over landfilling. As of 2025, 11 states and Washing-ton, DC, have laws that restrict food waste from being landfilled, with some laws more stringent than others. Composting is one way to align with both Army policy and local laws. Several installations have on-post composting operations, and others send food waste to nearby commercial compost facilities, where those are available. In FY 2024, 33 installations reported food recycling, which includes composting, anaerobic digestion, and other food-waste diversion. If composting on-post, a suitable location, equipment, and labor are needed. Multiple methods of composting for an installation must be considered. But composting can be worthwhile and may be more economical than landfilling. When installations are deciding how to manage food waste, they should consider their resources, organic waste generation tonnage, labor availability, and potential for cost savings. Depending on their location, on-post and off-post commercial options may be possible.

28 May 2026

Encouraging USACE Implementation of Engineering Critical Assessment (ECA): A Pre-ECA Screening Tool and Fracture-Resistance Screening Tool

Abstract: The US Army Corps of Engineers (USACE) manages a large inventory of hydraulic steel structures (HSS). These HSS are aging, and upon inspection, many show signs of damage including large discontinuities in their members, which threaten the HSS operation. Simply repairing every discontinuity will ensure continued HSS operation but may be unnecessarily expensive. Therefore, USACE seeks to balance its constrained budget with safe, reliable HSS operation. One balancing method is the concept of fitness for service. A discontinuity is evaluated using an acceptance criteria based on the principles of structural analysis and fracture mechanics called an engineering condition assessment (ECA) that decides whether it is fit for service. If a discontinuity is fit for service, the HSS will continue regular operations; if it is not fit for service, the discontinuity will be considered a defect and repaired. However, USACE has not widely adopted ECA. Because of resource constraints, engineers often choose to conservatively repair without considering ECA. This study seeks to alleviate the difficulty in committing resources to an ECA in two ways: (1) by providing logical justification for performing an ECA and (2) by reducing the resources necessary for analysis by providing a fracture-resistance screening tool.

27 May 2026

Multi-Temporal Geomorphic Change and Application of the Coastal Engineering Resilience Index Along the Mississippi Mainland Beaches and Dunes

Abstract: This report addresses the Mobile District’s request for a representative resilient beach and dune profile for the Mississippi mainland beach and dune project. The report summarizes a workflow that uses a custom ArcGIS Pro toolbox and 10 lidar datasets spanning a 22-year period of analysis. The workflow involves (1) lidar data compilation; (2) the extraction of geomorphic features, such as shorelines and dune toes and crests, on over 5,800 profiles along the Mississippi mainland coast; (3) the calculation of Coastal Engineering Resilience Index values for each transect for each lidar dataset; (4) selection of representative resilient profiles for various datasets; (5) development of synthetic profiles and Coastal Engineering Resilience Index (CERI) calculations on those profiles; and (6) data delivery and the development of a Web service hosting the project outcomes. The results of these analyses indicate that the protective width (i.e., from the shoreline to the seawall along the coast) is a major contributor to the resilience of a given section of beach. However, the resilience of these estuarine beaches can also be enhanced by increasing protective elevation. Overall, the work demonstrates the value of applying these workflows and toolboxes during the engineering planning and design phase.

26 May 2026

Financing Natural Infrastructure: Hunter’s Point South, Queens, New York

Purpose: Greater application of natural infrastructure (NI) approaches calls for more widely accessible information about leveraging resources and opportunities to design, construct, monitor, and adaptively manage projects that incorporate natural features. Because NI techniques vary widely by location, purpose, and scale, no standard process currently exists for securing funds and establishing financing mechanisms. This document is part of a series sharing lessons learned and showcasing successful examples of developing and implementing NI projects through innovative partnerships, funding, and financing strategies. The series is intended for federal and nonfederal practitioners who play a role in the planning and management of NI projects worldwide. This technical note describes the development and funding process for the Hunter’s Point South waterfront park development, a community-driven initiative that transformed an abandoned postindustrial site into a multipurpose recreational space with enhanced coastal flood protection and affordable housing. Hunter’s Point South achieves a long-standing vision for Long Island City’s waterfront and serves as a model for accessible, climate-resilient design. This research effort is a collaboration between the Engineering With Nature® (EWN®) and Systems Approach to Geomorphic Engineering (SAGE) programs of the US Army Corps of Engineers (USACE).

21 May 2026

Evaluation of Shore Protection Alternatives at Crescent Beach, Indiana

Abstract: This report documents a numerical modeling investigation of shore protection alternatives at Crescent Beach, Indiana. The integrated flow, wave, sediment transport, and morphology change Coastal Modeling System (CMS) and the long-term shoreline evolution model, GenCade, were applied to evaluate alternatives. Sediment, elevation, and hydrodynamic data were collected nearby to improve model calibration and validation. Eight alternatives were evaluated, with coastal structures in four, beach nourishments in three, and one with both. Structures other than the continuous rubble ridge (Alternative 4) had minimal or negative influences on sediment transport. Stone sizes and costs were estimated for Alternative 4 using StormSim and extremal forcing from the Coastal Hazards System (CHS) Great Lakes Study, but CMS does not predict impacts that justify rubble ridge construction costs. CMS and GenCade were applied to beach nourishments across a range of volume and sediment grain size distributions. Model evaluations indicate that beach nourishment is the most effective shoreline protection technique, using coarse sand mixed with small stones to achieve a median grain size (d50) of 1.80 millimeters successfully extends the beach nourishment lifecycle, and increasing nourishment volume to 87,455 cubic meters to span in front of Mount Baldy substantially increases downdrift benefits.