Adjacent Water Bodies Research Articles

Effects of farming intensification on avian species richness and abundance within Jos metropolis, Nigeria

With an emphasis on pesticide use and landscape features, this study examines how agricultural development affects the diversity and abundance of farmland bird species. The purpose of the study is to evaluate the effects of many factors on bird populations, including cropping patterns, pesticide frequency, and landscape elements including trees, water bodies, hedgerows, and grass cover. The issue being addressed is the decline in biodiversity brought on by an increase in farming practices and a reliance on pesticides that upset ecosystems. The study uses interviews in addition to line transect surveys over five farmlands to collect data on pesticide use and landscape features. The methodology comprised 200-meter transects separated into 100-meter parts for morning and evening bird surveys. Statistical approaches, including species richness and abundance comparison across farmlands with different pesticide use levels and cropping techniques, were used to analyse the data. The results showed that farmlands without pesticides had better biodiversity, while areas with frequent pesticide usage had significantly lower species richness and abundance. Bird diversity was only slightly increased by mixed cropping systems, grass cover, trees, hedgerows, and adjacent water bodies. The study comes to the conclusion that fostering diverse landscapes and lowering pesticide use can help lessen the loss of biodiversity. To improve agricultural bird conservation, it suggests focused interventions, education initiatives, and policies that support biodiversity.

Abstract 4138321: Marine Microplastic Levels and the Prevalence of Cardio-Metabolic Diseases in Coastline Counties: An Ecological Analysis

Background: Micro- and nanoplastics are an emerging risk factor for the development of cardiovascular diseases. The association of marine microplastic levels (MMLs) with the burden of cardiometabolic diseases at a population level remains unexplored. Aim: To investigate the association between the average microplastic concentration in the ocean water body within 200 nautical miles of US coastline surveyed between 2015 and 2020, assigned to its most adjacent coastline county, and the prevalence of type 2 diabetes (T2D), coronary artery disease (CAD), and stroke in those counties. Methods: Microplastic concentration data within 200 nautical miles of the US coastline was spatially analyzed in ArcGIS Online to calculate mean MMLs. The coastal counties were stratified into four categories based on MMLs in the adjacent ocean water body: low (0-0.005 pieces/m 3 ), medium (0.005-1 pieces/m 3 ), high (1-10 pieces/m 3 ), or very high (≥10 pieces/m 3 ). BRFSS 2019-2020 survey data was used to correlate with the prevalence of type 2 diabetes (T2D), coronary artery disease (CAD), and stroke in these counties. Univariate and population-weighted multivariate quasi-Poisson regression adjusted for median county age, sex, physician access, and baseline community vulnerability theme of the US climate vulnerability index (CVI) was used to evaluate unadjusted and adjusted associations between disease prevalence and MMLs. Results: The mean age of the population was 43 ± 6 years. The mean prevalence of T2D, CAD, and stroke was significantly higher in counties with very high MMLs (13.03%, 8.94%, and 4.17%, respectively) compared to low MMLs (11.23%, 7.43%, and 3.51%, respectively, p < 0.001). The counties with very high MMLs exhibited an 18% higher adjusted prevalence of T2D (PR: 1.18 [1.13 – 1.23], p < 0.001), 7% higher adjusted prevalence of CAD (PR: 1.07, [1.03 – 1.11], p < 0.001), and 9% higher adjusted prevalence of stroke (PR: 1.09, 95% CI: 1.05 – 1.13, p < 0.001) compared to those with low levels. Conclusion: Our study establishes a significant association between marine microplastic levels and cardiometabolic disease prevalence in coastal counties.

Youth Engagement in Water Quality Monitoring: Uncovering Ecosystem Benefits and Challenges

A youth-centric participatory mapping approach was employed to monitor the lower Mill Creek, an urban waterway located in Cincinnati, Ohio, by collecting geospatial data points on surface water quality and ecological assets. Utilizing the ArcGIS Field Maps application, a digital survey-based tool was developed to identify key areas related to ecological assets and urban water management challenges. The purpose of this citizen science approach was to allow researchers to capture and understand community perspectives and insights while engaging in scientific research that focuses on identifying geographic vulnerability areas and ecological assets. The primary objective was to empower local community groups and residents in an environmental justice neighborhood to understand the current opportunities and constraints of the adjacent waterbody, enabling informed decision-making for future planning initiatives that benefit both conservation and remediation efforts aligned with local values and needs. A youth-centric participatory mapping approach was employed to monitor the lower Mill Creek, an urban waterway in Cincinnati, Ohio, through the collection of geospatial data on surface water quality and ecological assets. The findings, based on hotspot analysis, revealed significant spatial clustering of heavy debris near the barrier dam and the lower portion of Mill Creek, where it converges with the Ohio River. This accumulation is attributed to the structural features of the barrier dam’s inner flood catchment area, which traps debris during rainfall events. Although no areas showed spatial significance for perceived ecological services, students identified specific areas with esthetic and biodiversity value, particularly at Mill Creek’s confluence with the Ohio River and along the northern stretch of the stream corridor. These findings provide valuable insights for guiding future conservation and remediation efforts that reflect both community values and environmental priorities.

Evaluation and mitigation of potentially toxic elements contamination in mangrove ecosystem: Insights into phytoremediation and microbial perspective

Mangroves, essential coastal ecosystems, are threatened by human-induced Potentially-toxic-elements (PTEs) pollution. This study analyzed PTEs distribution, phytoremediation potential, and rhizosphere microbial communities in Taiwan's Xinfeng mangrove forest. Significant variations in physicochemical and PTEs concentrations were observed across adjacent water bodies, with moderate contamination in the river, estuary, and overlying water of mangroves sediment. The partition-coefficient showed the mobility of Bi, Pb, Co, and Sr at the water-sediment interface. The geochemical-indices revealed high Bi and Pb contamination and moderate Zn, Sr, Cu, and Cd contamination in sediment. The overall pollution indices indicated the significant contamination, while moderate ecological risk was found for Cd (40 ≤ Eri < 80). Mangroves Kandelia obovata and Avicennia marina exhibited promising PTEs phytoremediation potential (Bi, Cd, Mn, Sr, and Co). Metagenomics indicated a diverse microbial community with N-fixation, P-solubilization, IAA synthesis, and PTEs-resistance genes. These findings underscore the need for targeted conservation to protect these critical habitats.

Glufosinate-ammonium increased nitrogen and phosphorus content in water and shaped microbial community in epiphytic biofilm of Hydrilla verticillata

Glufosinate-ammonium (GLAM) can be released into adjacent water bodies with rainfall runoff and return water from farmland irrigation. However, impacts of GLAM on aquatic organisms remain unclear. In this study, changes in water quality, plant physiological parameters and epiphytic microbial community were investigated in wetlands with Hydrilla verticillata exposed to GLAM for 24 days. We found GLAM addition damaged cell and reduced chlorophyll a content in Hydrilla verticillata leaves, and increased ammonium and phosphorus in water (p < 0.001). The α-diversity increased in bacterial community but decreased in eukaryotic community with GLAM exposure. Neutral community models explained 62.3 % and 55.0 % of the variance in bacterial and eukaryotic communities, respectively. Many GLAM micro-biomarkers were obtained, including some clades from Proteobacteria, Bacteroidete, Actinobacteriota, Phragmoplastophyta, Annelida and Arthropoda. Redundancy analysis revealed that GLAM concentration was positively correlated to Flavobacterium, Gomphonema and Closterium but negatively to Methyloglobulus and Methylocystis. Network analysis revealed that 15 mg/L GLAM disturbed the interactions among phytoplankton, protozoa, metazoan and bacteria and reduced the stability of the microbial communities compared to 8 mg/L GLAM. GLAM shaped the nitrogen and phosphorus cycle related bacterial genes. This study highlights that herbicides are non-neglectable factors affecting the efficiency of aquatic ecological restoration in agricultural areas to control agricultural non-point source pollution.

How does urban form explain water cooling effect heterogeneity: A case study in Wuhan, China

Water bodies in urban areas are considered to be natural and effective cooling factors that can help mitigate the urban heat island (UHI) effect. Previous studies highlighted the cooling effect is determined by the size and landscape of the water bodies. However, it is unclear how the urban form surrounding water bodies influences the water cooling effect received by human activity space. Using high resolution data and a multiple linear regression model, the effect of various 2D/3D urban form factors on the average water cooling intensity (AWCI) and water cooling intensity (WCI) at the fine scale were examined in Wuhan City on hot days. We further verified the spatial heterogeneity of the relationship between urban form factors and WCI according to the distance to and size of adjacent water bodies. The AWCI of the entire surrounding area were correlated with building morphology indicators. Urban form indicators effectively explained the variations of WCI at the fine scale, indicating that a mixture of large building volume density (BVD) with small building density (BD), and an aggregated impervious surface area (ISA) with a complex shape were conducive to WCI. Additionally, building morphology had a larger impact on the cooling effect around small water bodies and in the outer buffer area of water bodies. In comparison, the cooling effect of the area surrounding large water bodies was more affected by the landscape of the ISA. We therefore propose a differentiated urban planning strategy to take full use of the limited water cooling effect.

Effects of road salt, egg predation and alterations to the egg-mass jelly layers on the embryos of spotted salamander Ambystoma maculatum

Road de-icing salt has been used to make winter driving safer. However, its eventual drainage into adjacent water bodies has caused detrimental effects on organisms in those aquatic communities, including amphibians. We used the spotted salamander Ambystoma maculatum as a model species and examined whether there would be additive or interactive effects of road salt, egg predation from wood frog Lithobates sylvaticus tadpoles, and alteration to egg-mass jelly layers on the hatching rate, incubation period, snout-vent length (SVL) and developmental stage of hatchlings. We found neither main nor interactive effects of salt on the measured traits, which contradicts some of the previous studies. The other body of previous studies, however, showed observational and experimental evidence that amphibian populations became locally adapted to saline water. Given the roadside origin of our study animals, our negative results provide insight into the ubiquity of local adaptation to saline water among amphibian populations. We also found that egg predation and the presence of egg-mass jelly layers negatively affected the incubation period, SVL, or development in the predicted manners based on the O2 demand-supply balance within egg masses. These responses might be altered by dissolved salt if populations naive to freshwater salinisation were exposed to saline water. Keywords: aquatic pollution, community ecology, conservation, larval amphibians, Lithobates sylvaticus

Identifying Barriers Preventing Stormwater Pond Buffer Implementation in Coastal South Carolina

Buffer zones are ecotones between upland areas and adjacent water bodies. They often consist of plant communities that stabilize shorelines, act as barriers reducing transport of fertilizer and lawn debris into water bodies, uptake nutrients and heavy metals, and provide habitat for wildlife. Few regulations exist that require vegetated buffers around stormwater ponds, and their widespread implementation has not occurred around ponds in coastal South Carolina. This lack of regulation on buffer requirements has potentially reduced the effectiveness of stormwater ponds and highlights the need to identify barriers preventing residents from implementing vegetated buffers. To investigate the barriers preventing the installation or support for stormwater buffer zones in coastal communities, an electronic survey was sent by e-mail through the South Carolina Department of Natural Resources and Ashley Cooper Stormwater Education Consortium listservs. Of the 646 respondents, 382 met the study criteria and identified owning a property with a pond or living in a neighborhood with one. Respondents were asked questions to determine their knowledge and perceptions of vegetated buffers, as well as their level of communication with landscape professionals. Results from this research indicate that residents are aware of the benefits vegetated buffer zones provide and prefer ponds with buffer zones over ponds with no buffer zones. This study reveals the following potential barriers preventing stormwater pond vegetated buffer zones: 1) limited knowledge of the costs associated with installation of vegetated buffer zones, 2) inadequate communication between residents and landscape professionals who maintain ponds, 3) respondents perceived lack of control over pond-related decisions, and 4) social norms within neighborhoods such as grass sod standards and an aversion to non-manicured vegetation. These findings can be used by stormwater professionals to help increase adoption of stormwater pond best management practices (BMPs) and improve water quality protection in South Carolina.

Development of an integrated approach to the analysis and forecast of hydrographic and bathymetric data of water bodies and tailings ponds

There is a need for an effective monitoring solution for water quality control in tailings dumps and adjacent water bodies in order to prevent environmental pollution. This article highlights the importance of water quality monitoring and surveillance to prevent pollution. It is proposed to develop a mobile robotic complex equipped with sensors for monitoring water bodies and tailings, which is also capable of measuring underwater topographic data. The objects of study were a tailings pond and water bodies. The authors analyzed existing technical monitoring solutions, designed and developed a robotic complex, echolocation device, tested them on specific sites (the tailings dump of the Zhayrem Mining and Processing Plant and the Ishim River), conducted laboratory analysis of water samples, classified the results. Additionally, they obtained 2D and 3D maps of the bottom, and entered all collected data into a developed database and software. The developed complex demonstrated high accuracy of movement (an error of about 0.2 m on the x axis and 0.1 m on the y axis) and the ability to register environmental parameters such as temperature, humidity, PH. Data analysis for 2021–2023 showed a significant excess of recycled water discharged into the evaporator pond, which emphasizes the importance of monitoring and management of water resources. The research applies ARIMA models, neural networks to predict water body parameters. The results obtained indicate the high efficiency of the developed robotic complex and methods for analyzing data on water resources. These methods can be used in industry, scientific research and environmental projects to regularly monitor water quality and take measures to protect it

Environmental impact of mechanical site preparation on mineral soils in Sweden and Finland — a review

Mechanical site preparation (MSP) is deliberate soil disturbance which is undertaken to improve the conditions for forest regeneration. Disc trenching and mounding are the dominant MSP practices currently used in Sweden and Finland. In this paper, the impacts of MSP on the soil, water quality, greenhouse gas (GHG) emissions and ground vegetation of mineral soil sites in Sweden and Finland are reviewed. The practices considered are patch scarification, mounding, inverting, disc trenching, and ploughing, which together represent a wide range of soil disturbance intensity. The environmental effects of MSP in this region have not been studied extensively. The environmental impact of MSP derives from the process of creating microsites which involves horizontal and/or vertical redistribution of soil and soil mixing. This typically affects decomposition, element circulation and leaching, vegetation coverage and uptake of nutrients and water, and possibly erosion and sediment exports. Following disc trenching or mounding the effects on GHG emissions appear to be minor over the first two years. For a few years after disc trenching concentrations in soil water collected below ridges are higher than that below furrows for some elements (e.g., NO3-, NH4+, Mg2+, and total or dissolved organic C). The physical and chemical effects of ploughing remain detectable for several decades. There is little evidence about how the effects of forestry activities in upland areas on soil-water chemistry are transferred to adjacent surface water bodies, including what role streamside discharge areas play. MSP increases the tree biomass C store and may increase the total ecosystem C store. The impact of MSP on the cover and abundance of ground vegetation species depends on the composition of the original plant community, MSP intensity, and the establishment rate of different species. Species cover generally seems to decline for late succession understory species, while pioneer and ruderal species can benefit from the microsites created. Areas containing lichens which are used for reindeer forage require special consideration. More research is needed on the environmental effects of MSP, particularly regarding its long-term effects. Further efforts should be made to develop efficient site-preparation practices which better balance the disturbance intensity with what is needed for successful regeneration.

Evaluation of Textile Wastewater Treatment via ETP in Bangladesh

Textile liquid waste possesses a substantial biochemical oxygen demand and total suspended solids, hence posing a significant risk of contaminating adjacent water bodies if not appropriately managed. The primary aim of the study is to examine the pH condition of water from the inlet and outlet of the ETP (Effluent Treatment Plant) in two specific regions. Two natural groups in Bangladesh include Tonga Bari, Ashulia, Savar, and Dhaka. Another natural group is “The Emakulet Textile Ltd,” located in Purboponchash, Dhamrai, Dhaka. Raw liquid waste was collected from two textile industry and applied some test procedure in the laboratory by varying different design parameters such as pH, DO (Dissolved Oxygen), BOD5 (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), TDS (Total Dissolved Solids), TSS (Total Suspended Solids), Turbidity, Fe2+, pH was tested by a pH meter at 25℃ temperature. DO also tested by a sensor machine (FLEXA) which shows the values of dissolved oxygen in ETP waste water. To collect BOD5 value needed 5 days minimum also used MnSO4, H2SO4 to get BOD5 value from the incubator. Turbidity was tested by Digital Turbidity meter. The results showeds that the pH condition of water from the inlet is satisfied but others parameter from the inlet sample is not in the range of ECR, 1997. The selected two areas of ETP given the maximum and minimum parameters found, DO in the inlet of two selected areas was (0) from the inlet. The maximum BOD5 value was 126 mg/l from the inlet which crosses the limit of ECR-1997 but after treatment it was 47 mg/l. The detailed experimental results demonstrated that, ETP water is fully treated and all parameter acceptable according to ECR, 1997. In this analysis, it is anticipated that the implementation of a cost-effective treatment approach could serve as an incentive for industrial proprietors to engage in effluent treatment, so contributing to the enhancement of water body quality in Bangladesh.

Mehkužci (polži in školjke) zgornjega toka Neretve

During a survey taking place from 29.6.2022–2.7.2022 in Bosnia and Herzegovina in the river-floodplain system of the upper Neretva River around Ulog, 51 species of molluscs were found at 12 sampling sites. Besides manual sampling in the water bodies, the main sampling technique consisted of sieving of river deposits, to maximise the coverage of species diversity. The majority of the species were terrestrial gastropods (45 out of 51), most of them common species of forests and moist areas, but also of grassland. In the Neretva River itself and in adjacent waterbodies, six species of freshwater molluscs were found. Among them, at least three species of spring snails of the taxonomically challenging genera Belgrandiella, Bythinella, and Paladilhiopsis were found, the latter one only in river deposits. Future research should focus on truncatelloidean snails in the groundwater system of the upper course of the Neretva River. Furthermore, a broader investigation of the mollusc fauna of Bosnia and Herzegovina would help to clarify taxonomically unresolved questions of species of the Balkan region and possibly reveal species new for science.

Hydrochemical dynamics of stream following rainfall events at agricultural catchments in New Zealand

One of the prerequisites for efficiently managing lake water quality is reliable data regarding the quantity and quality of inflows water, mainly the export of nutrients from the catchment area during rainfall events. We investigated the dynamic characteristics of hydrochemicals concerning rainfall events in agricultural stream waters flowing into eutrophic lakes situated on the North Island’s central plateau of New Zealand. We utilized isotopic composition of water (δ2H-H2O and δ18O-H2O) and nitrate (δ15N-NO3- and δ18O-NO3-) along with high-frequency hydrochemical data for source identification of water and nitrate during a drought period (2020). Our findings indicate that it is essential to initially grasp the fundamental mechanisms associated with rainfall events to formulate effective strategies for minimizing nutrient losses. The methodology outlined in this research integrates stable isotope hydrology with water quality monitoring initiatives, facilitating the understanding and managing the primary governing mechanisms behind diverse contaminant losses from land to adjacent water bodies, explicitly focusing on nitrates. This approach establishes a framework that can assist in devising measures for water quality improvement capable of anticipating the repercussions of substantial rainfall events more effectively.

Restricted colloidal-bound phosphorus release controlled by alternating flooding and drying cycles in an alkaline calcareous soil

Colloid-facilitated phosphorus (P) migration plays an important role in P loss from farmland to adjacent water bodies. However, the dynamics of colloidal P (Pcoll) release as influenced by irrigation in alkaline calcareous soil remains a knowledge gap. The present study, monitored the dynamic change of Pcoll under different water management strategies: 1) control, 2) flooding, and 3) alternating flooding and drying cycles. Soil water-dispersible colloids (0.6 nm-1 μm) were extracted by combining filtration and ultrafiltration methods. The contents of P, cation and organic carbon in the water-dispersible colloids were determined and the stability and mineral composition of colloidal fractions were characterized. The results showed that Pcoll ranged from 16.5 to 25.5 mg kg−1 and represented 42.8%–64.9% of the water-extracted P in the control. Flooding significantly decreased the Pcoll content by 16.0%–62.1% (mean 32.7%) and it may be attributed to the dissolution of colloidal iron (Fe) bound P. The alternating flooding and drying treatment significantly reduced the Pcoll content by 11.6%–88.0% (mean 67.6%). The Pcoll content of the flooding event was always greater than the Pcoll content of the drying event during flooding and drying cycles. Redundancy analysis and random forest modeling showed that the colloidal calcium (Ca) and ionic strength in soil solutions had negative correlations with the Pcoll content, and pH, ionic strength and truly dissolved P were the critical factors affecting Pcoll. Drying of the flooded soil led to the decrease of pH and the increase of ionic strength, colloidal Ca content and positive charges of colloid surfaces, which promoted colloid aggregation and enhanced soil P sorption capacity. This restricted the loss potential of Pcoll. In summary, controlled flooding and drainage when managed correctly have a role to play in mitigating Pcoll loss from P-enriched calcareous soils.

Impact of water loss on sustainability of the Mississippi River channel in its deltaic reach

AbstractThe Mississippi River channel from New Orleans to the Gulf of Mexico (GOM) is a key deep draft navigation channel and an active deltaic lobe. Natural and engineered lateral exits from this reach into adjacent receiving basins historically has provided mineral sediment for wetland accretion in the face of rising relative sea level and supported estuarine‐coastal food webs. However, our analysis indicates water losses from the channel have increased by 25% since 2004 due to (1) bank failures during large floods since 2012 that have created several large exit channels downriver of the flood protection levee, and (2) the opening of an engineered diversion at West Bay in 2004. This has resulted in a 60%–80% loss in stream power in the lowermost navigation channel that is accompanied by net shoaling between 2012 and 2022 and an increased dredging need. Our 2022 survey in the GOM exit passes indicates that only 20% of the freshwater, 5% of the total suspended sediment (2% of the sand) at New Orleans now reaches the GOM: this supports previous research indicating the delta front is retreating after centuries of progradation. Together these results indicate that (1) river containment and the sustainability of the navigation channel is threatened, (2) sediment load reaching the seaward end of the delta may be insufficient to avoid major degradation, and (3) the increased freshwater flux into adjacent shallow coastal water bodies has unknown implications for coastal hypoxia and food webs, including commercial species (e.g., oysters) and marine mammals. Future acceleration in sea level rise rates and tropical storm frequency/intensity would likely worsen these trends.

Crushed concrete and biochar: A sustainable solution for vegetated roofs

Besides providing several important ecosystem services, vegetated roofs can provide also ecosystem disservices, such as leaching nutrients that cause eutrophication in adjacent water bodies. Such downsides and limited knowledge on hydrologic performance of vegetated roofs in a cold climate may prevent their wider implementation. Another issue concerns sustainability of materials used in vegetated roofs. A replicated field experiment was run for four years in southern Finland to study the performance of vegetated roof ecosystems with substrates containing crushed lightweight concrete, biochar or crushed brick. All materials were locally sourced and recycled. Nutrient dynamics, soil fauna, vegetation and stormwater management were monitored. Alkaline concrete efficiently reduced phosphorus leaching due to high pH compared with that of a neutral brick substrate. Amending concrete substrate with 20% (v/v) biochar improved retention of nitrogen and in < 20 mm events also rainfall. Vegetation grew equally well in all treatments. The abundance of soil animals, nematodes and enchytraeids, varied markedly over time, driven by changes in substrate moisture. Rainfall was efficiently retained and runoff detained, especially during summer, which is the rainiest season in Finland. We conclude that concrete and biochar as materials used in substrate can provide an effective, innovative and sustainable solution for vegetated roofs.

Spatiotemporal Patterns of Heavy-Metal Pollution in Coastal Pinqing Lagoon (Southern China): Anthropogenic and Hydrological Effect

Coastal lagoons connecting the land and sea provide essential ecosystem services. However, emerging environmental issues such as environmental pollution and ecological degradation from rapid socio-economic development in coastal zones of south China are becoming increasingly prevalent. This study examined the spatiotemporal variation, sources, assessments, and driving forces of heavy metals based on core and surface sediments collected from Pinqing Lagoon, a coastal lagoon in South China. Sediment cores (PQ1, PQ2, and PQ3) showed distinct vertical variations in the content of Cu, Cd, Zn, Pb, As, and Sb with an average coefficient of variation (C.V.) of 0.25. However, a relatively lower vertical variation (C.V. mean = 0.13) was shown by the other elements (Mn, V, Ni, Cr, and Co). Although Cu was the chief pollutant heavy metal and it had mean values of 1.6 and 1.7 for the enrichment factor (EF) and contamination factor (CF), respectively, Cd posed the highest ecological risk (Eri mean = 36.34). A century-scale anthropogenic disturbance and growing industrial activities in the lagoon area have caused heavy-metal pollution in Pinqing Lagoon. Wastewater discharge into the lagoon over the past 30 years has further aggravated the pollution. The land-use pattern changes in the catchment and removal of polluting industries resulted in a shift in the center of gravity of heavy-metal pollution in the surface sediment of the lagoon. When integrated with the available data, significant pollution gradients were observed suggesting that the pollution level of Pinqing Lagoon was slightly higher than the marginal sea (Honghai Bay) but significantly lower than the adjacent inland water bodies (Gongping and Chisha Reservoirs). This difference attributes unique hydrodynamic conditions to the Pinqing Lagoon, which consistently mitigates environmental pollution by lying at the interface between inland water and the coastal sea in South China. These conditions resulted in the relatively low contamination degree (CD mean = 7.5) and the low ecological risk index (RI mean = 70) over the past 150 years in Pinqing Lagoon.

Effect of a natural wetland on the removal of antibiotics and antibiotic resistant bacteria in a treated sewage treatment effluent

Antibiotics are often released into the environment via disposal or excretion. A selection pressure is then initiated that leads to the acquisition of antibiotic resistance genes (ARGs) in environmental bacteria, thus encouraging the environmental spread of antibiotic resistance. The purpose of this study was to examine the nutrient and antibiotic reducing capacity of the Point au Chene assimilation wetland that receives the city of Thibodaux, Louisiana, USA treated sewage wastewater. Water samples were collected from four sampling sites along the wetland every month from May 2022 to April 2023. Water quality was assessed at each stage of flow within the wetland including the direct discharge (input) site, wetland midpoint, wetland endpoint, and a control site adjacent to the Thibodaux Sewage Plant, but separated by a hardwood ridge that prevents the intrusion of treated effluent. Standard water quality parameters, coliform bacteria, and antibiotic concentrations were determined. Results indicated antibiotic, coliform, nitrate, sulfate, and ammonia concentrations were significantly higher at the input site than other wetland sites. The antibiotics, tetracycline and sulfamethoxazole were reduced by 75 % in the wetlands. More than 80 % of penicillin and bacitracin were removed throughout the wetland. The input site additionally expressed the highest amount of multi-drug resistance and bacterial diversity of all sites. ARGs have been identified throughout the wetland system, with bacterial isolates testing positive for the ARGs bacA, sul2, and tetA, coding for resistance to bacitracin, sulfonamide, and tetracycline antibiotics respectively. The wetland has a positive impact of reducing the nutrients, antibiotics, and ARB in the treated sewage prior to release to adjacent waterbodies.

History and performance of the Everglades STA-3/4 periphyton-based stormwater treatment area (PSTA)

The Everglades Stormwater Treatment Areas (STAs) retain phosphorus (P) from stormwater runoff before it enters the Everglades Protection Area. These large treatment wetlands are extremely efficient in reducing total P (TP) concentrations. However, in some cases, the STAs may require additional measures to reach and/or maintain mandated discharge TP concentrations. One such option, a Periphyton-based Stormwater Treatment Area (PSTA) Cell, was constructed in 2005 on 40 ha at the outflow region of one flow-way in STA-3/4. This PSTA Cell was built to determine operational and engineering requirements associated with the implementation of this technology on a large scale. The PSTA Cell has supported an oligotrophic, periphyton-rich treatment wetland over its operational period of record. This system has consistently produced annual flow-weighted mean (FWM) outflow TP concentrations at or near the mandated outflow TP levels. The PSTA Cell maintained optimal treatment performance when subjected to hydraulic conditions observed in other full-scale STA cells (i.e., deeper water depths, pulsed flows, and major storm events). The PSTA Cell's treatment performance appeared to be better (FWM outflow concentrations ∼9 μg L−1) during continuous flows for 21 days compared to intermittent flow periods. Daily PSTA Cell outflows often were ≤ 13 μg L−1 when inflow TP concentrations were ≤ 22 μg L−1. The PSTA Cell also removed additional P from very low inflow concentrations (< 15 μg L−1). Seepage into the PSTA Cell occurred when its stage was lower than stages in adjacent water bodies, but seepage was greatly reduced when stages in the PSTA Cell were increased and the difference in stage between the PSTA Cell and adjacent bodies was reduced. TP concentrations in seepage water were usually higher than the PSTA Cell's inflow or surface water TP concentrations, therefore, the PSTA Cell performance did not benefit from seepage inflows. Over the 13 water years of operation, accretion of new soil (TP < 300 mg kg−1) did not result in nutrient gradients within the PSTA Cell that might affect P performance. Overall, the PSTA Cell study achieved its goal of providing operational and engineering insights for the implementation of this technology on a larger scale, and the PSTA Cell consistently attained ultra-low-P concentrations (mean ± standard deviation) of 10 ± 3 μg L−1 over its operational period of record.

Impacts of repeated coastal flooding on soil and groundwater following managed dike realignment

Coastal defense structures (e.g., dikes, seawalls) protect vulnerable communities along marine coastlines and estuaries from the physical and chemical influences of adjacent water bodies. These structures are susceptible to overtopping or breaching by tides and waves, with risks amplified by climate change-induced sea-level rise. Repeated inundation by saline water can contaminate freshwater resources and salinize soil, impacting land-use activities, including agricultural productivity. Managed ecosystem-based dike realignment and salt marsh restoration can provide alternatives to traditional coastal adaptation approaches. We assess the changes to soil salinity at a managed dike realignment project prior to the transformation from a diked terrestrial environment to an estuarine environment. Baseline data are compared to conditions following 8–10 months of intermittent flooding at spring tides.Results show that an increase in salinity occurred over the entire site in the shallow subsurface, with the most significant contamination occurring in low-lying areas. Bulk soil electrical conductivity (salinity proxy) measured from geophysical surveys increased from the previous freshwater condition of ∼300 μS/cm to over 6000 μS/cm following <20 flood events, while successive flooding resulted in increased soil moisture as infiltrated floodwater propagated to greater depths. Sediment deposition occurred at high rates, with up to 4 cm of sediment deposited per flood, converting much of the previously cultivated land into tidal mudflats. Deeper sediments and groundwater (i.e., >1.8 m depth) were not impacted over the time scale of this research. This study demonstrates that intermittent shallow flooding can rapidly increase moisture content and soil salinity in surficial sediments and, in turn, adversely impact conditions suitable for agricultural crop production. The realignment zone serves as an engineered analog of coastal flooding, presenting an opportunity to investigate how low-lying coastal environments may experience regular flooding in the future due to sea-level rise and intensifying coastal storms.