Environmental Monitoring and Assessment最新文献

Fish mass mortality events (FMMEs) represent an escalating ecological crisis, significantly threatening aquatic biodiversity, particularly in North African freshwater ecosystems. Addressing a critical knowledge gap in this region, our study presents the first comprehensive assessment of FMMEs in Moroccan aquatic ecosystems, including freshwater systems and estuaries, based on meticulous monitoring from January 2020 to December 2022. During this three-year period, we documented 18 FMMEs across 16 distinct ecosystems, with a notable increase in frequency observed during the summer and autumn months. Estuaries emerged as critical hotspots for these events, exhibiting the highest frequency of FMMEs and highlighting their vulnerability to climatic and anthropogenic pressures. Our findings indicate a staggering loss of at least 7.8 million fish, with Atherina boyeri, accounted and identified as the most affected species by FMMEs. The families Cyprinidae and Mugilidae experienced the most substantial impacts, including significant biomass losses in Chelon saliens, Chelon labrosus, and Cyprinus carpio. Additionally, endemic species such as Luciobarbus maghrebensis and Luciobarbus rabatensis also faced considerable declines. These events underscore severe ecological disruptions and provide novel insights into species distribution and interactions, including the first recorded presence of Oreochromis niloticus in previously undocumented regions. This research underscores the urgent need for targeted conservation strategies and proactive interventions to mitigate the ecological and socioeconomic ramifications of FMMEs. By addressing these critical issues, we can better protect Moroccan freshwater ecosystems that are at risk of further biodiversity loss.

Permanent crops rely heavily on pesticides. Their short-term behaviour has already been characterised under laboratory conditions. However, their degradation in the field is still poorly understood. Furthermore, studies that relate pesticide residues in soil with their application history are still scarce, despite their relevance for inferring the historical and diffuse dimensions of pollution. This work explores the spatial and temporal dynamics of pesticide residues in soil under the light of their application records and the accuracy of the predicted environmental concentrations (PEC). To achieve these purposes, 270 soil samples were collected at 5 sampling times over the 2022 growing season, in 18 peach orchards from east-central Portugal. Moreover, the data extracted from the application records was used to obtain predicted levels which were compared with the measured results. A total of 37 residues were analysed. Overall, 32 of these were detected back in, at least, one sample. Glyphosate and AMPA were the most frequently found and had the highest median concentrations. The comparison between predicted and measured environmental concentrations (MEC) suggests that pesticide decay was generally slower than expected. Glyphosate, AMPA, fluopyram and tebuconazole showed a high potential for resulting in background concentrations in soil. Our results highlight the need for regular and comprehensive monitoring, being recommended long-term assessments of the persistence and fate of pesticides under realistic conditions. Furthermore, our results also stress the necessity of more studies on reasons for PEC-MEC mismatch, a factor of concern considering the regulatory relevance of PEC values.

Acacia invasion has shown a negative impact on the water resources of forest streams. Therefore, studies need to be conducted demonstrating the importance of managing invasive species to preserve stream and forest ecosystems. This study investigates the effects of Acacia invasion on the water quality of Kerangas forest streams in Brunei. Water samples were collected from an Acacia-invaded (IN) stream and a non-invaded (NIN) stream during the dry season at three locations along each stream. Water properties, including pH, conductivity, salinity, total dissolved solids (TDS), phosphate, nitrate, ammonia, and nitrite, were analyzed using in situ and laboratory methods. The results showed that Acacia invasion significantly increased pH (from 4.01 to 5.68), nitrate (by 256%), and phosphate (by 250%) levels, while reducing conductivity (by 208%) and salinity (by 20%) compared to non-invaded streams. These findings suggest that Acacia invasion alters water chemistry, potentially posing risks to aquatic ecosystems. Effective management strategies, such as controlling Acacia spread and restoring native vegetation, are essential to mitigate these impacts and preserve forest water resources.

Sikkim, located in the Eastern Himalayas, is a prominent tourist destination. The state exhibits a diverse climatic range spanning from subtropical to alpine zones. Springs and glacier-fed rivers serve as the primary water sources for both residents and tourists. Furthermore, rapid urbanization, climate change, altered precipitation patterns and frequent landslides have significantly stressed these water sources, especially in the lower subtropical regions, resulting in declining water quality. This study aimed to assess heavy metal contamination in surface water, considering both natural and anthropogenic sources, and its impact on different population groups. A total of 155 water samples were collected from households, rivers, springs and hot springs across pre-monsoon, monsoon and post-monsoon seasons. Heavy metals (Al, As, Cd, Co, Cr, Cu, Hg, Fe, Mn, Ni, Pb and Zn) were analyzed, and water quality was assessed using various water pollution indices. The findings revealed that the water is unsuitable for consumption without treatment. A novel approach, Monte Carlo simulation, was employed in health risk assessment, incorporating sensitivity and uncertainty analyses. This method provided greater accuracy in evaluating both carcinogenic and non-carcinogenic risks, with the results indicating moderate to high cancer risks through ingestion and dermal absorption. It is strongly recommended that treated water be used for drinking to mitigate exposure to heavy metal contamination in the region.

Drought events are complex and uncertain, and drought sensitivity assessments are beneficial for ecological conservation and improving early warning mechanisms. Understanding ecosystems’ response to drought is vital for ecological conservation and climate change research. Ecological drought, a concept describing drought from an ecosystem perspective, lacks sufficient research regarding its effects on agricultural ecosystems, especially in the Huang-Huai-Hai Plain. This study identifies ecological drought using a three-dimensional clustering method and examines its spatiotemporal patterns. By developing the Winter Wheat Ecological Drought Sensitivity Index (EDSIWW), it quantifies the impact of drought on winter wheat and employs machine learning models to assess environmental factors influencing this relationship. Findings show that 26 ecological drought events occurred between 2000 and 2022, predominantly in autumn and winter, with an average duration of 132 days, affecting over 80% of the study area. These events coincided with winter wheat’s growth cycle, significantly impacting its gross primary production, followed by solar-induced chlorophyll fluorescence, leaf area index, and near-infrared reflectance. Environmental factors like land surface temperature, soil moisture, and vapor pressure deficit exhibited complex influences on wheat’s sensitivity to drought. This research offers new insights into the drought-wheat relationship and provides scientific guidance for agricultural management and drought prevention.

The urbanization process is complex and lengthy, typically resulting in dual changes in the socioeconomic structure and ecological environment. However, in the context of arid environments and initial urbanization, emerging towns undergo evolutionary processes different from those of traditional cities. This study focuses on a typical town, analyzing its growth under the combined effects of arid conditions and incipient urbanization. The results reveal a unique urbanization trajectory in the hinterland of southern Xinjiang: transitioning from refined agricultural planting to shrubland and bare land dominated by natural factors and then to impervious surfaces. While the pattern was complex, the direction of transition was clear. Using the town’s establishment in 2014 as a critical node for urbanization initiation, shrubland emerged as the most sensitive land type, with a proportional increase by a factor of 2.6 from 2010 to 2015. This was driven by the abandonment of cultivated land, which decreased by 11.3% during the study period, with 78% of the newly added shrubland area converted from cropland. By applying the Markov model together with the InVEST model, the study predicted urban land-use transition patterns over the next 5 years and revealed that urbanization primarily exacerbates the instability of water yield in the surrounding region. This study uniquely addresses the gap in understanding the impacts of the urbanization process of emerging towns in arid regions and its associated ecological processes. A detailed investigation of such urbanization is crucial to mitigating issues like disorderly land use and promoting the sustainable development of small and medium-sized towns.

Heavy metals are the primary pollutants in surface sediments of coastal area, and they can affect aquatic organisms and human health through accumulation and release into the environment. To investigate the spatial distribution, sources, and ecological hazards of heavy metals, this study analyzed the data on the contents of heavy metals in surface sediments of coastal areas in Lianyungang. The results indicate that significant spatial differences exist in the distribution of these metals. The average contents of As, Cd, Cr, Ni, Pb, and Zn were 5.6, 0.53, 41.4, 21.2, 12.4, and 49.6 mg/kg, respectively. Only the average value of Cd exceeded the background value, while the others were all lower than their respective background values. The ecological risk index of individual elements ranked from high to low is as follows: Cd > As > Ni > Pb > Cr > Zn. Additionally, the comprehensive ecological hazard index suggests that the ecological risk of the coastal sediments in Lianyungang is generally at a low to moderate level, with Cd being the major contributor. Numerous analyses show that Cr, Ni, and Zn mainly stem from industrial wastewater discharge, As and Cd mainly originate from agricultural and aquaculture activities, and Pb mainly comes from port traffic and atmospheric deposition.

Air pollution is a significant global issue that impacts public health, particularly in urban areas where pollution levels often exceed safe limits. The Air Quality Index (AQI) serves as a key metric to assess the concentration of harmful pollutants such as particulate matter (PM), ozone, and nitrogen oxides. This study conducts an extreme value analysis (EVA) of AQI data from five major Indian cities—Delhi, Mumbai, Kolkata, Chennai, and Hyderabad—and eight other metropolitan cities worldwide, including Dhaka, Chengdu, and Bogota. The goal is to evaluate the probability of extreme pollution events and compare the seasonal patterns of air quality in these cities. Our findings indicate that cities like New Delhi and Dhaka consistently experience AQI levels that exceed hazardous thresholds, particularly during the winter months and festival seasons. This study provides critical insights into the air quality crisis in India and other regions, emphasizing the need for targeted policy interventions, including stricter emission regulations, adoption of cleaner energy sources, and enhanced public awareness campaigns to mitigate the effects of extreme pollution events.

Pulicat is India’s second-largest freshwater lagoon having unique biological ecosystem and economical importance. The lagoon systems are highly polluted by the microplastics (MP) due to anthropogenic activity and microplastics are highly emerging kind of contaminant in the environment. Samples were collected from a part of the lagoon near the mouth region. Morphological identification of microplastics with microscope and polymer identification using ATR-FTIR and Micro-Raman spectroscopy was carried out. From the result, average abundance of the MP particles in surface water ranges 3.12 ± 1.53 particles per 1000 l and 701 ± 198 particles per kg for sediments, respectively. Microplastics < 1 mm (1–1000 microns) are dominant in size. Fibres, fragments and films were most occupied in physical form, respectively, in microplastic samples and polypropylene (PP) and polyethylene (PE) were the predominant polymer types composited in MP particles. This study concludes that Pulicat lagoon is significantly polluted by microplastic, which is mostly contributed by fishing and mismanagement of plastic wastes.