20 Aug 2025

Trade-offs Between Field and Remote Geomorphic Monitoring of Coastal Marsh Restoration Sites

Abstract: Coastal marsh restoration presents geomorphic monitoring challenges because these sites are often remote or inaccessible, and time and financial resources for field data may be limited. Yet, elevation and shoreline characteristics contribute to the overall health and longevity of coastal marshes. The expansion of Uncrewed Aircraft System (UAS) technology and new satellite platforms offer opportunities to complement ground-based geomorphic monitoring and overcome the challenges of traditional field methods. Here, we compare field-based and remote-sensing approaches to monitor two restored coastal wetlands in Louisiana. At Spanish Pass, methods for measuring site elevation, shoreline position, and shoreline geomorphic types were compared. Ground surveys strongly correlated with UAS-lidar digital elevation model (DEM) elevations (R2 = 0.97. UAS and satellite imagery were accurate to within 3 meters of field-shoreline positions, and UAS-lidar-derived shorelines had the lowest error. At LaBranche, UAS-lidar DEM data were paired with airborne lidar and legacy ground surveys to track temporal changes in elevation, indicating minimal elevation change. The study demonstrates the accuracy and utility of satellite and UAS remote sensing for monitoring shoreline positions and elevations but notes that shoreline classifications could be improved with additional quantification. These findings help practitioners assess the trade-offs and benefits of various monitoring methods.

19 Aug 2025

Bioaccumulation in Fish (Cyprinodon variegatus) During Rejuvenations of a Thin Active Cap over Field-Aged PCB Contaminated Sediment: The Effect of Clean Versus Contaminated Ongoing Influx

Abstract: Repeated addition of activated carbon (AC) via the water column was applied to rejuvenate sorption capacity of thin AC-amended sand caps placed over polychlorinated biphenyl- (PCB) contaminated marine bed sediment receiving ongoing input of sediment (contaminated or clean) in mesocosms. Bioaccumulation of PCBs in sheepshead minnows (Cyprinodon variegatus) from bed sediment was reduced by repeated application of reju-venating AC when the ongoing input was contaminated. However, when the input sediment was clean, the novel AC addition increased fish uptake of bedded PCBs in the first 60-days of the 90-day experiments. The 79 % increase of bedded PCB bioaccumulation in fish, for clean versus contaminated inputs, was statistically signifi-cant (p < 0.05) in experiments where the rejuvenating AC was applied. Equilibrium concentrations in low- density polyethylene (LDPE) passive samplers did not fully explain bioaccumulation. Field implications of this research include setting appropriate temporal expectations of this novel remediation strategy regarding the primary desired effect (i.e., PCB bioavailability reductions).

19 Aug 2025

Cooperative Molecular Interaction-Based Highly Efficient Capturing of Ultrashort- and Short-Chain Emerging Per- and Polyfluoroalkyl Substances Using Multifunctional Nanoadsorbents

Abstract: The short-chain and ultrashort-chain per- and polyfluoroalkyl substances are bioaccumulative, carcinogenic to humans, and harder to remove using current technologies. Herein, we report the development of nonafluorobutane-sulfonyl and polyethylene-imine -conjugated Fe3O4 magnetic nanoparticle-based magnetic nanoadsorbents and demonstrated the novel adsorbent has the capability for highly efficient removal of six different short- and ultrashort-chain PFAS from drinking and environmental water samples. Reported experimental data indicates by capitalizing the cooperative hydrophobic, fluorophilic, and electrostatic interaction processes, NFBS-PEI-conjugated magnetic nanoadsorbents can remove ~100% short-chain perfluorobutanesulfonic acid within 30 min from the water sample with a maximum absorption capacity qm of ~234 mg g−1. Furthermore, to show how cooperative interactions are necessary for effective capturing of ultrashort and short PFAS, a comparative study has been performed using PEI-attached magnetic nanoadsorbents without NFBS and acid-functionalized magnetic nanoadsorbents without PEI and NFBS. Reported data show the ultrashort-chain perfluoropropanesulfonic acid capture efficiency is the highest for the NFBS-PEI-attached nanoadsorbent. Moreover, reported data demonstrate that nanoadsorbents can be used for effective removal of short-chain PFAS and ultrashort-chain PFAS simultaneously from reservoir, lake, tape, and river water samples within 30 min, which shows the potential of nanoadsorbents for real-life PFAS remediation.

18 Aug 2025

Archaeogenomic Analysis of Chesapeake Atlantic Sturgeon Illustrates Shaping of Its Populations in Recovery from Severe Overexploitation

Abstract: Atlantic sturgeon (Acipenser oxyrinchus ssp. oxyrinchus) has been a food resource in North America for millennia. However, industrial-scale fishing activities following the establishment of European colonies led to multiple collapses of sturgeon stocks, driving populations such as those in the Chesapeake area close to extinction. While recent conservation efforts have been successful in restoring census numbers, little is known regarding genomic consequences of the population bottleneck. Here, we characterize its effect on present-day population structuring and genomic diversity in James River populations. To establish a pre-collapse baseline, we collected genomic data from archaeological remains from Middle Woodland Maycock’s Point (c. 200–900 CE), as well as Jamestown and Williamsburg colonial sites. Demographic analysis of recovered mitogenomes reveals a historical collapse in effective population size, also reflected in diminished present-day mitogenomic diversity and structure. We infer that James River fall- and spring-spawning populations likely took shape in recent years of population recovery, where genetic drift enhanced the degree of population structure. The mismatch of mitogenomic lineages to geographical–seasonal groupings implies that despite their homing instinct and differential adaptation manifested as season-specific behaviour, colonization of new rivers has been a key ecological strategy for Atlantic sturgeon over evolutionary timescales.

18 Aug 2025

Coastal Environments: LiDAR Mapping of Copper Tailings Impacts, Particle Retention of Copper, Leaching, and Toxicity

Abstract: Tailings generated by mining account for the largest world-wide waste from industrial activities. Copper is relatively uncommon, with low concentrations in sediments and waters, yet is very elevated around mining operations. On the Keweenaw Peninsula, 140 mines extracted native copper from the Portage Lake Volcanic Series, part of an intercontinental rift system. Between 1901 and 1932, two mills at Gay sluiced 22.7 million metric tonnes of copper-rich tailings into Grand Traverse Bay. About 10 MMT formed a beach which migrated 7 km to the Traverse River Seawall. Another 11 MMT are moving underwater along the coastal shelf, threatening Buffalo Reef. Remote sensing techniques documented geospatial environmental impacts and initial phases of remediation. Aerial photos, ALS LiDAR/MSS surveys, and recent UAS overflights aid comprehensive mapping efforts. Because natural beach quartz and basalt stamp sands are silicates of similar size and density, percentage stamp sand determinations utilise microscopic procedures. Copper leaching is elevated by exposure to high DOC and low pH waters, characteristic of riparian environments. Lab and field toxicity experiments, plus benthic sampling, all confirm serious impacts of tailings on aquatic organisms. Mining companies should end coastal discharges and also adopt the UNEP “Global Tailings Management Standard for the Mining Industry”.

18 Aug 2025

Cell-Penetrating Peptide-Mediated Delivery of Gene-Silencing Nucleic Acids to the Invasive Common Reed Phragmites australis via Foliar Application

Abstract: RNA interference-based gene silencing has been increasingly explored for potential applications to control invasive species. At least two major hurdles exist when applying this approach to invasive plants: (1) the design and screening of species- and gene-specific biomacromolecules made of DNA, RNA, or peptides that can suppress the expression of target genes efficiently, and (2) the delivery vehicle needed to penetrate plant cell walls and other physical barriers. In this study, we investigated the cell-penetrating peptide-mediated delivery of multiple types of GSAs to knock down a putative phytoene desaturase gene in the invasive common reed. Both microscopic and quantitative gene expression evidence demonstrated the CPP-mediated internalization of GSA cargos and transient suppression of PDS expression in both treated and systemic leaves up to 7 days post foliar application. Although various GSA combinations and application rates and frequencies were tested, we observed limitations, including low gene-silencing efficiency and a lack of physiological trait alteration, likely owing to low CPP payload capacity and the incomplete characterization of the PDS-coding genes in P. australis. Our work lays a foundation to support further research toward the development of convenient, cost-effective, field-deployable, and environmentally benign gene-silencing technologies for invasive P. australis management.

13 Aug 2025

Examination of Activated Carbon Losses During Open Water Placement of Amended Dredged Material for Bioaccumulation Control

Purpose: The purpose of this study was to evaluate the potential losses of both powdered and granular activated carbon (AC) resulting from open water placement of AC-amended dredged material to reduce contaminant bioaccumulation. The study examined the results of model predictions, a laboratory dump test, and a field demonstration project performed at the Ashtabula Lake Erie placement site.

12 Aug 2025

Applying the Working with Nature Philosophy to Navigation Infrastructure Projects

Abstract: In 2008, the World Association for Waterborne Transport Infrastructure published a position paper describing a Working with Nature philosophy aimed to change how the sector approaches navigation and port infrastructure projects. In 2018, Pianc published guidance on implementing WwN. Pianc’s guidance presents a six-step process that encourages consideration of site-specific ecosystem characteristics and WwN opportunities at early stages of project development, early stakeholder engagement and integration of WwN into the development of project objectives before design begins. By incorporating WwN applications during conception, the WwN approach provides the most promising opportunities to affect positive outcomes for the environment. This holistic understanding of ecosystem processes and socioeconomic interactions realises environmental impacts can be minimised while concomitantly seeking opportunities to enhance ecosystem functions at various spatial and temporal scales. Project delivery thus goes beyond avoiding or compensating for negative project impacts and seeks multi-sector ecosystem and socioeconomic benefits. Applied in practice, WwN can increase habitat functionality, reduce energy associated with construction or maintenance, and enhance the short- and long-term delivery of ecosystem services. Projects consistent with the WwN philosophy achieve their underlying engineering objectives, alongside various co-benefits, consistent with the environmental, societal and economic sustainability pillars.

7 Aug 2025

Financing Natural Infrastructure: Lightning Point, Alabama

Purpose: This technical note explores the restoration of Lightning Point, an award-winning natural infrastructure project led by The Nature Conservancy (TNC) in coastal Alabama. The story of Lightning Point provides an exemplar case study of successful coordination of cross-sector partnerships and the use of ecosystem services valuation to attract project funding.

7 Aug 2025

Continued Development of Methods for the Determination of Legacy and Insensitive Munitions from Environmental Matrices: Addition of Four Degradation Products and One Internal Standard to Previously Developed 29-Analyte Method

Abstract: To continue improving separation methods of explosive analytes and their degradation products, chromatographic methods from Environmental Protection Agency (EPA) 8330B, Strategic Environmental Research and Development Program (SERDP) 2722, and Environmental Sensors for Explosives were modified to include the separation of four additional analytes and one internal standard so that a total of 36 analytes could be resolved on a single column. Four degradation compounds, 3-amino-1,2,4-triazol-5-one (ATO); 1 methyl-3-nitroguandine (MeNQ); 2 methoxy-5-nitroaniline (MENA); and 4 methoxy-3-nitroaniline (iMENA) were added to the analytical method. The internal standard, 3,5-dinitrotoluene, was also added to the method to extend its application. Additionally, an analytical method on gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS) were explored for the analytes of interest.