8 May 2026

Development of a Trace Element Signature Library Across a Large Watershed for Assessing Large-Scale Fish Movement Patterns

Abstract: Using trace element or stable isotope analysis has proven to be an effective means to characterize early life history and large-scale movement patterns in fishes. Target species are assessed for analyte concentrations occurring in calcified hard structures and compared to signatures noted from associated watersheds. However, this approach assumes analyte absorption occurs in proportion to their availability, and success relies heavily on the ability to identify unique water chemistry signatures between neighboring watersheds within a defined study area. Our objective was to establish a trace element signature profile for major tributaries occurring within the Mississippi River Valley (MRV). Water samples were obtained from 49 stations and evaluated for the presence and relative concentration of Ba, Sr, Ca, Fe, and Li. Analyte concentrations (milligrams per liter) varied across the sampled stations, although Li occurred at only four stations, primarily in the upper reaches of the MRV, and provided little discriminatory use. Concentrations of Fe and Ca depicted an inverse relationship, with Ca having higher concentrations in the upper third of the MRV while Fe typically had higher concentrations in the lower third. Ratios of Ba:Ca and Sr:Ca (millimole per mole) exhibited the greatest utility for delineating river-specific or reach-specific signatures.

4 May 2026

Freshwater Wetland Carbon Flux Analysis Pertinent to the Net Emissions Analysis Tool Improvement: Method Development and Testing

Palustrine wetlands are ecosystems of interest due to their capacity to sequester large amounts of greenhouse gases. This field study in Washington and Idaho was conducted as proof of concept of methods for measuring carbon emissions in palustrine wetlands. The regions of Washington and Idaho were chosen as they span three different Environmental Protection Agency (EPA) Level 1 ecoregions in a relatively close geological area. Data were collected across all three ecoregions in an effort to detail the potential differences between palustrine wetlands within them. Carbon dioxide flux measurements were compared across two instruments: LICOR 8,100A and CIRAS-4. Supporting data related to vegetation and site characteristics were incorporated into the overall analyses. Results suggest that carbon dioxide flux varies in relation to several factors. Additional research will be required to inform the application of site-specific data which can improve the application of tools designed to quantify project scale estimates for net greenhouse gas emissions.

9 Apr 2026

Vertebrates in Trade that Pose High Invasion Risk to the United States

Abstract: The United States imports thousands of live vertebrate species annually as part of legal trade. Escapes and releases from captivity are major pathways of invasion, however, the risk posed by the thousands of imported vertebrate species has not been systematically assessed. We conducted a horizon scan that used a data-driven climate match to filter a list of nearly 15,000 taxa drawn from across the globe of imported fish, amphibians, reptiles, birds, and mammals for rapid assessment by taxonomic experts. Experts evaluated 840 species and identified 32 as having the highest risk for establishment, spread, and negative impacts. Of those high-risk species, the majority have the capacity to disrupt ecosystem processes via their role as top predators or the unique ecological niches that they occupy, while several of the snake species pose a threat to human health. High-risk species were often scored with high confidence while in contrast, low scores were attributed to a combination of ecological redundancy, low propagule pressure, or low climate match while low confidence arose from a lack of information in the literature. Our study therefore highlights legally imported species likely to cause the greatest harm with the recognition that many other species could also become invasive in the United States. The ranked list of vertebrate threats can be used to prioritize watchlists and inform the development of targeted regulations for importation can be applied to regions to provide a rapid, preliminary screening for large pools of potential invaders.

20 Feb 2026

Overview of the Coastal Storm Model Development and Results for the Deer Island Restoration Study Using the Engineering With Nature® Toolkit

Abstract: The Coastal and Hydraulics Laboratory of the US Army Engineer Research and Development Center presents this study as a comprehensive numerical model development and validation approach that can be employed to simulate winds, waves, and water levels during significant storm events for the Deer Island Restoration Project in Mississippi. Leveraging validated storms from the South Atlantic Coastal Study, this research utilized the Coastal Storm Modeling System with the coupled Advanced Circulation (ADCIRC) and Steady-State Spectral Wave (STWAVE) models. As part of this effort, the ADCIRC mesh was updated to encompass the Deer Island region and two variations on elevated water level scenarios were incorporated. Specifically, 10 validated storms were simulated, with varying sea-level conditions, to represent a range of feasibility-level proxy events from a 1- to 10,000-year annual exceedance frequency. The modeling outcomes provide a detailed depiction of water levels, wave heights, and storm surge impacts on Deer Island under different sea-level rise scenarios. These results offer critical insights into the potential effects of the restoration project on Deer Island and the surrounding areas. The findings can inform decision-makers and contribute to formulating effective guidelines for restoration projects within the Mississippi region and in coastal areas facing similar challenges worldwide.

11 Feb 2026

Assessing Relative Wetland Flood Risk Management Benefits Using COPE: An Exploration of Capacity, Opportunity, Payoff, and Efficacy

Abstract: Wetlands reduce flood risk, but measuring their performance and benefits is challenging due to the highly variable nature of the factors, including landscape features, land use, and climate, that shape flood response. An evidence-based index was developed to rapidly assess the potential flood risk management benefits of wetland restoration. These benefits are measured by combining the Capacity (C), Opportunity (O), Payoff (P), and Efficacy (E) indicators into a single index, called COPE. Capacity captures the internal wetland characteristics that alter flood peak attenuation potential. Opportunity reflects watershed characteristics that control the effectiveness of internal wetland capacities. Payoff quantifies the population exposed to high flood risk, and Efficacy reflects the ability of communities to respond to flooding. Literature evidence for the C and O indicators suggests that flood risk is reduced by increasing wetland storage in small basins with hillslopes or in moderate to large riverine basins. Literature evidence for the E index suggests that multiple indicators can capture the potential for disproportionate harm to vulnerable communities. A case study demonstrated that the P indicator strongly influences the relative-benefits score produced by COPE, but the C, O, and E indexes can alter the score substantially when values deviate from average conditions.

10 Feb 2026

Sustainable Dredged Material Management on the Ohio and Kanawha Rivers to Achieve Multiple Benefits

Abstract: This technical report showcases the sustainable dredge material management practices by the US Army Corps of Engineers (USACE) on the Ohio and Kanawha Rivers. Over the years, USACE Huntington District (LRH) has continually adapted their navigation operations, dredge maintenance activities, and sediment beneficial use processes in response to changing local and regional hydrodynamic conditions, the results from monitoring, and proactive stakeholder engagement. This report highlights three project sites—Bonanza Bar and R. C. Byrd Locks and Dam on the Ohio River and Winfield Locks and Dam on the Kanawha River—that exemplify sustainable dredge practices consistent with Engineering With Nature® principles. By implementing these best practices, LRH has established a more sustainable dredging program that generates economic, environmental, and social benefits beyond the mere removal of sediment from the federal navigation channel. These innovative practices have successfully achieved multiple benefits while executing USACE’s navigation mission. The data and lessons learned from these projects can be applied to other riverine projects aiming to use sediment beneficially, enhance the development of USACE sustainable dredging practices, and inspire future projects.

9 Jan 2026

Review of Hydroacoustic Data Associated with Small-Diameter Vinyl and Timber Pile Driving Operations

This review investigates root-mean-square sound levels, peak sound levels, and single-strike sound exposure levels resulting from small-diameter vinyl and timber pile driving operations with sufficient supporting information to assess potential impact on endangered species identified in the NOAA acoustic impact calculator. We identify 49 relevant records associated with installing timber pilings 14 in. in diameter and smaller and one record associated with vinyl piling. While acceptable for use as proxy data within the NOAA tool, the records exhibit significant unexplainable scatter of as much as +20 dB. Example calculations show that well intentioned hypothetical proposals coordinated in the permit application process could project vastly different impacts to endangered species. We therefore conclude that, within the framework of current practices and tools, these data cannot support informed decision-making by US Army Corps of Engineers (USACE) regulators as to whether small-scale timber or vinyl pile driving operations will jeopardize the continued existence of protected species or result in the destruction or adverse modification of critical habitat to comply with the Endangered Species Act. We recommend supplementing existing data with targeted collections as well as developing pile-specific coordination and assessment guidance for use by USACE regulators during the permitting process.

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.

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.

16 Sep 2025

Review of Threatened and Endangered Plant Species Potentially Impacting US Army Corps of Engineers Mission Areas

Abstract: This special report summarizes federally threatened and endangered plant species that have most affected recent or ongoing US Army Corps of Engineers (USACE) projects in terms of dollars spent on research, management, and mitigation. We also assess which of these highest cost-associated species are most likely to benefit from further research and conservation efforts, with the goals of species recovery and delisting.