The impact of marine pollution on the probability of business failure: A case study of the Mar Menor lagoon.

The impact of coastal water quality and its interaction with business results is still an unexplored field. This study uses a probit model and estimates marginal effects to investigate the impact of chlorophyll a concentration in the Mar Menor (Spain) coastal waters on the probability of business failure of firms located in this area. This coastal area has been in a critical ecological condition since 1980 when intensive irrigation agriculture expanded to the surroundings of this salted lagoon. Therefore, identifying the most damaging productive activities is crucial to convince companies and policymakers to overcome this situation. The most remarkable findings of our study are the following. First, we find opposing geographical impacts on the probability of business failure for companies located on the Mar Menor coast: A location effect showing a decreasing probability of business failure for companies located near the Mar Menor and a pollution effect indicating an increased probability of failure due to proximity to water pollution. Second, we further identify the economic sectors in which the pollution effect outweighs the location effect. We find that most of the examined productive activities seem to be negatively affected by the pollution effect, overcoming the positive effect of being located near the Mar Menor. Third, marine eutrophication increases the probability of business failure for some economic activities but not for others. Concretely, agricultural and transport activities benefit from being near the coast despite the quality of the water. These firms' probability of failure decreases when they are located near the sea), whereas a 1 mg/m3 increase of chlorophyll a raises the probability of business failure for accommodation services (8.4%), minor trade (9.5%), financial and real estate services (11%), and industrial and building activities (14.4%). This paper highlights the need to design effective environmental regulations to preserve the area of Mar Menor, considering the specific productive characteristics of the different agents. We highlight the sectors requiring additional incentives to implement pro-environmental strategies and reduce their contribution to environmental pollution. The main insights from this analysis are applicable to other coastal areas around the world that suffer from marine eutrophication due to human activities.

Unraveling the enzymatic and antibacterial potential of rare halophilic actinomycetes from Algerian hypersaline wetland ecosystems.

The study aimed to isolate rare halophilic actinomycetes from hypersaline soils of Algerian inland Wetland Ecosystems "Sebkhas-Chotts" located in arid and hot hyperarid lands with international importance under the Ramsar Convention and to explore their enzyme-producing and antibacterial abilities. The halophilic actinomycetes were selectively isolated using agar-rich media supplemented with 5, 10, and 15% (W/V) of total salts. Thirty-one isolates were obtained and 16S rRNA gene sequencing analysis revealed the presence of members affiliated to rare halophilic actinobacterial genera (Actinopolyspora and Nocardiopsis) accounting for 74.19% (23 isolates out of 31) and 25.8% (8 isolates), respectively. Both phylotypes are alkalitolerant and halophilic thermotolerant actinomycetes displaying significant hydrolytic activities relative to (amylase, asparaginase, cellulase, esterase, glutaminase, inulinase, protease, pectinase, xylanase), and over 96% of tested isolates exhibited all common enzymes, mainly active at 10% of growing salt. In addition, high antibacterial activity was observed against Bacillus cereus, Bacillus subtilis, Micrococcus luteus, and Staphylococcus aureus. The findings showed that saline wetlands ecosystems represent a rich reservoir for the isolation of significant rare halophilic actinomycetes with potential adaptive features and valuable sources for novel bioactive metabolites and biocatalysts of biotechnological interest.

Effects of Polycyclic Aromatic Hydrocarbons on the Composition of the Soil Bacterial Communities in the Tidal Flat Wetlands of the Yellow River Delta of China.

Polycyclic aromatic hydrocarbons (PAHs) are pervasive organic pollutants in coastal ecosystems, especially in tidal flat wetlands. However, the mechanisms through which PAHs impact the soil bacterial communities of wetlands featuring a simple vegetation structure in the Yellow River Delta (China) remain largely unclear. In this study, we examined soil samples from two sites featuring a single vegetation type (Suaeda salsa) in the Yellow River Delta. Specifically, we investigated the impacts of PAHs on the diversity and composition of soil bacteria communities through high-throughput 16 S rRNA sequencing. PAHs significantly increased the soil organic carbon content but decreased the total phosphorus content (p = 0.02). PAH contamination notably reduced soil bacterial community α diversity (Shannon index) and ß diversity. Furthermore, PAHs significantly altered the relative abundance of bacterial phyla, classes, and genera (p < 0.05). Specifically, PAHs increased the relative abundance of the bacterial phyla Acidobacteriota and Gemmatimonadota (p < 0.05), while decreasing the relative abundance of Bacteroidota, Desulfobacterota, and Firmicutes compared to the control wetland (p < 0.05). Moreover, PAHs and certain soil properties [total nitrogen (TN), soil organic carbon (SOC), total phosphorus (TP), and total salt (TS)] were identified as key parameters affecting the community of soil bacteria, with the abundance of specific bacteria being both negatively and positively affected by PAHs, SOC, and TN. In summary, our findings could facilitate the identification of existing environmental problems and offer insights for improving the protection and management of tidal flat wetland ecosystems in the Yellow River Delta of China.

Selenium volatilization in plants, microalgae, and microorganisms.

The augmented prevalence of Se (Se) pollution can be attributed to various human activities, such as mining, coal combustion, oil extraction and refining, and agricultural irrigation. Although Se is vital for animals, humans, and microorganisms, excessive concentrations of this element can give rise to potential hazards. Consequently, numerous approaches have been devised to mitigate Se pollution, encompassing physicochemical techniques and bioremediation. The recognition of Se volatilization as a potential strategy for mitigating Se pollution in contaminated environments is underscored in this review. This study delves into the volatilization mechanisms in various organisms, including plants, microalgae, and microorganisms. By assessing the efficacy of Se removal and identifying the rate-limiting steps associated with volatilization, this paper provides insightful recommendations for Se mitigation. Constructed wetlands are a cost-effective and environmentally friendly alternative in the treatment of Se volatilization. The fate, behavior, bioavailability, and toxicity of Se within complex environmental systems are comprehensively reviewed. This knowledge forms the basis for developing management plans that aimed at mitigating Se contamination in wetlands and protecting the associated ecosystems.

Phenolic compounds weaken the impact of drought on soil enzyme activity in global wetlands.

Soil enzymes play a central role in carbon and nutrient cycling, and their activities can be affected by drought-induced oxygen exposure. However, a systematic global estimate of enzyme sensitivity to drought in wetlands is still lacking. Through a meta-analysis of 55 studies comprising 761 paired observations, this study found that phosphorus-related enzyme activity increased by 38% as result of drought in wetlands, while the majority of other soil enzyme activities remained stable. The expansion of vascular plants under long-term drought significantly promoted the accumulation of phenolic compounds. Using a 2-week incubation experiment with phenol supplementation, we found that phosphorus-related enzyme could tolerate higher biotoxicity of phenolic compounds than other enzymes. Moreover, a long-term (35 years) drainage experiment in a northern peatland in China confirmed that the increased phenolic concentration in surface layer resulting from a shift in vegetation composition inhibited the increase in enzyme activities caused by rising oxygen availability, except for phosphorus-related enzyme. Overall, these results demonstrate the complex and resilient nature of wetland ecosystems, with soil enzymes showing a high degree of adaptation to drought conditions. These new insights could help evaluate the impact of drought on future wetland ecosystem services and provide a theoretical foundation for the remediation of degraded wetlands.

Non-negligible impact of microplastics on wetland ecosystems.

There has been much concern about microplastic (MP) pollution in marine and soil environments, but attention is gradually shifting towards wetland ecosystems, which are a transitional zone between aquatic and terrestrial ecosystems. This paper comprehensively reviews the sources of MPs in wetland ecosystems, as well as their occurrence characteristics, factors influencing their migration, and their effects on animals, plants, microorganisms, and greenhouse gas (GHG) emissions. It was found that MPs in wetland ecosystems originate mainly from anthropogenic sources (sewage discharge, and agricultural and industrial production) and natural sources (rainfall-runoff, atmospheric deposition, and tidal effects). The most common types and forms of MPs identified in the literature were polyethylene and polypropylene, fibers, and fragments. The migration of MPs in wetlands is influenced by both non-biological factors (the physicochemical properties of MPs, sediment characteristics, and hydrodynamic conditions) and biological factors (the adsorption and growth interception by plant roots, ingestion, and animal excretion). Furthermore, once MPs enter wetland ecosystems, they can impact the resident microorganisms, animals, and plants. They also have a role in global warming because MPs act as unique exogenous carbon sources, and can also influence GHG emissions in wetland ecosystems by affecting the microbial community structure in wetland sediments and abundance of genes associated with GHG emissions. However, further investigation is needed into the influence of MP type, size, and concentration on the GHG emissions in wetlands and the underlying mechanisms. Overall, the accumulation of MPs in wetland ecosystems can have far-reaching consequences for the local ecosystem, human health, and global climate regulation. Understanding the effects of MPs on wetland ecosystems is essential for developing effective management and mitigation strategies to safeguard these valuable and vulnerable environments.

Mechanisms underpinning microplastic effects on the natural climate solutions of wetland ecosystems.

Wetland ecosystems are vital carbon dioxide (CO2) sinks, offering significant nature-based solutions for global climate mitigation. However, the recent influx of microplastic (MP) into wetlands substantially impacts key drivers (e.g., plants and microorganisms) underpinning these wetland functions. While MP-induced greenhouse gas (GHG) emissions and effects on soil organic carbon (SOC) mineralization potentially threaten the long-term wetland C-climate feedbacks, the exact mechanisms and linkage are unclear. This review provides a conceptual framework to elaborate on the interplay between MPs, wetland ecosystems, and the atmospheric milieu. We also summarize published studies that validate possible MP impacts on natural climate solutions of wetlands, as well as provide extensive elaboration on underlying mechanisms. We briefly highlight the relationships between MP influx, wetland degradation, and climate change and conclude by identifying key gaps for future research priorities. Globally, plastic production, MP entry into aquatic systems, and wetland degradation-related emissions are predicted to increase. This means that MP-related emissions and wetland-climate feedback should be addressed in the context of the UN Paris Climate Agreement on net-zero emissions by 2050. This overview serves as a wake-up call on the alarming impacts of MPs on wetland ecosystems and urges a global reconsideration of nature-based solutions in the context of climate mitigation.

Recent advances towards micro(nano)plastics research in wetland ecosystems: A systematic review on sources, removal, and ecological impacts.

In recent years, microplastics/nanoplastics (MPs/NPs) have received substantial attention worldwide owing to their wide applications, persistence, and potential risks. Wetland systems are considered to be an important "sink" for MPs/NPs, which can have potential ecological and environmental effects on the ecosystem. This paper provides a comprehensive and systematic review of the sources and characteristics of MPs/NPs in wetland ecosystems, together with a detailed analysis of MP/NP removal and associated mechanisms in wetland systems. In addition, the eco-toxicological effects of MPs/NPs in wetland ecosystems, including plant, animal, and microbial responses, were reviewed with a focus on changes in the microbial community relevant to pollutant removal. The effects of MPs/NPs exposure on conventional pollutant removal by wetland systems and their greenhouse gas emissions are also discussed. Finally, current knowledge gaps and future recommendations are presented, including the ecological impact of exposure to various MPs/NPs on wetland ecosystems and the ecological risks of MPs/NPs associated with the migration of different contaminants and antibiotic resistance genes. This work will facilitate a better understanding of the sources, characteristics, and environmental and ecological impacts of MPs/NPs in wetland ecosystems, and provide a new perspective to promote development in this field.

Reveal the threat of water quality risks in Yellow River Delta based on evidences from isotopic and hydrochemical analyses.

This study aims to evaluate the seasonal and spatial characteristics of hydrochemistry and DO isotopes and identify the eco-environmental threats under the background of saline intrusion and human activities in Yellow River Delta (YRD). Analyses for major ions (i.e., K+, Na+, Ca2+, Mg2+, SO42-, HCO3- and Cl-), nitrate ion (NO3-) and isotopic composition are performed for precipitation, river water, wetland water and sea water. Based on the range of δ2H and δ18O as well as their relations, the mixing between multiple sources and evaporation are confirmed. Electrical conductivity (EC), concentration of NO3-, soluble sodium percentage (SSP) and magnesium hazard (MH) are employed as indicators to reflect the ecological risks from salinity, agricultural pollutants, sodium and magnesium. By hierarchical cluster analysis (HCA), the samples of wetland water are grouped associated with those of river water. The characteristic reflects 3 patterns of risks in wetlands, including saline intrusion, human activities and their mixed influence.

From source to sink: Review and prospects of microplastics in wetland ecosystems.

The source, distribution, migration, and fate of microplastics (MPs) in aquatic and terrestrial ecosystems have received much attention. However, the relevant reports in wetland ecosystems, the boundary area between water and land, are still rare. Where are the sources and sinks of MPs in the wetland? The latest researches have shown that the sources of MPs in wetlands include sewage discharge, surface runoff, and plastic wastes from aquaculture. Fibers and fragments are the most common shapes, and PE, PP, PS can be detected in water or sediment matrices, and biota of wetlands. The distribution is affected by hydrodynamic conditions, sediment properties, and vegetation coverage. Factors affecting the vertical migration of MPs include their own physical and chemical properties, the combination of substances that accelerate deposition (mineral adsorption and biological flocculation), and resuspension. Minerals tend to adsorb negatively charged MPs while algae aggregates have a preference for positively charged MPs. The wetlands vegetation can trap MPs and affect their migration. In water matrices, MPs are ingested by organisms and integrated into sediments, which makes them seem undetectable in the wetland ecosystem. Photodegradation and microbial degradation can further reduce the MPs in size. Although recent research has increased, we are still searching for a methodological harmonization of the detection practices and exploring the migration rules and fate patterns of MPs. Our work is the first comprehensive review of the source, distribution, migration, and fate of MPs in wetland ecosystems. It reveals the uniqueness of wetland habitat in the research of MPs and indicates the potential of wetlands acting as sources or sinks for MPs.