Effects Of Anthropogenic Activities Research Articles

Regulation of nitrite-dependent anaerobic methane oxidation bacteria by available phosphorus and microbial communities in lake sediments of cold and arid regions

As global anthropogenic nitrogen inputs continue to rise, nitrite-dependent anaerobic methane oxidation (N-DAMO) plays an increasingly significant role in CH4 consumption in lake sediments. However, there is a dearth of knowledge regarding the effects of anthropogenic activities on N-DAMO bacteria in lakes in the cold and arid regions. Sediment samples were collected from five sampling areas in Lake Ulansuhai at varying depth ranges (0–20, 20–40, and 40–60 cm). The ecological characterization and niche differentiation of N-DAMO bacteria were investigated using bioinformatics and molecular biology techniques. Quantitative PCR confirmed the presence of N-DAMO bacteria in Lake Ulansuhai sediments, with 16S rRNA gene abundances ranging from 1.72 × 104 to 5.75 × 105 copies·g−1 dry sediment. The highest abundance was observed at the farmland drainage outlet with high available phosphorus (AP). Anthropogenic disturbances led to a significant increase in the abundance of N-DAMO bacteria, though their diversity remained unaffected. The heterogeneous community of N-DAMO bacteria was affected by interactions among various environmental characteristics, with AP and oxidation-reduction potential identified as the key drivers in this study. The Mantel test indicated that the N-DAMO bacterial abundance was more readily influenced by the presence of the denitrification genes (nirS and nirK). Network analysis revealed that the community structure of N-DAMO bacteria generated numerous links (especially positive links) with microbial taxa involved in carbon and nitrogen cycles, such as methanogens and nitrifying bacteria. In summary, N-DAMO bacteria exhibited sensitivity to both environmental and microbial factors under various human disturbances. This study provides valuable insights into the distribution patterns of N-DAMO bacteria and their roles in nitrogen and carbon cycling within lake ecosystems.

Erratum to: Effects of anthropogenic activities and climate factors on the distribution of invasive alien species in China

Erratum to: Effects of anthropogenic activities and climate factors on the distribution of invasive alien species in China

Environmental and mineralogical studies on the stream sediments of Baltim–El Burullus coastal plain, North Delta, Egypt

This work is mainly concerned with the effect of anthropogenic activities and natural radioactivity due to the presence of highly radioactive black sand spots, factory construction, and shipping, in addition to other activities like agriculture on human beings. Forty samples were collected along Baltim–El Burullus coastal plain to detect the effect of these problems and determine the suggested solutions. The black sand of the Baltim–El Burullus coastal plain exhibits a considerable amount of economically heavy minerals, their ratio relative to the bulk composition in the investigated samples ranges from 3.18 to 10.5% with an average of 5.45%. The most important of them are magnetite, ilmenite, rutile, leucoxene, garnet, zircon and monazite. The existence of some radioactive-bearing accessory mineral deposits like zircon and monazite led to measuring the naturally occurring radionuclides 226Ra, 232Th and 40K to evaluate the excess lifetime cancer risk (ELCR). The results showed that these concentrations are 19.1 ± 9.73, 14.7 ± 9.53 and 211 ± 71.34 Bq kg−1 were lower than the corresponding reported worldwide average of 35, 45, and 412 Bq kg−1 for each radionuclide (226Ra, 232Th, and 40 K). The gamma hazard indices such as absorbed dose rate (Dair), the annual effective dose (AED), and excess lifetime cancer risk (ELCR) factor were computed in the investigated sediments and all the results were found (Dair = 26.4 nGy h−1, AED = 0.03 mSv year−1, ELCR = 0.0001) to be lower than the values suggested by the United Nations Scientific Committee on the effect of Atomic Research (59 nGy h−1, 0.07 mSv year−1 and 0.0029 for Dair, AED and ELCR, respectively). The study suggests that the black sand is safe to use in various infrastructure applications at Baltim–El Burullus coastal plain. The levels of radioactivity are not high enough to pose a risk to human health.

Benthic Foraminifera as Proxies of Paleoenvironmental Changes in the Sant’Elia-Foxi Canyon (Gulf of Cagliari, Italy, Western Tyrrhenian Sea)

Marine coastal areas are highly dynamic and fragile environments characterised by a complex interplay of biological, physical, and chemical factors. These areas are also affected by anthropogenic activities with the discharge of organic and inorganic contaminants that alters the quality of the environment. In this work, the effects of anthropogenic activities (i.e., urban and industrial development) on benthic foraminifera have been investigated along the A2TM core collected from the Sant’Elia-Foxi Canyon (Gulf of Cagliari, Sardinia—western Tyrrhenian Sea). The Gulf of Cagliari has experienced intense urbanisation since the beginning of the twentieth century with the establishment of petrochemical complexes and harbour activities. The A2TM core, dating from 1907 to 2013, was analysed with an integrated approach that includes grain size, organic matter, and benthic foraminifera characterisation compared with geochemical characterisation. The variations in the composition of the benthic foraminiferal assemblages and the Margalef diversity index are related to the altered environmental conditions that reflect the historical development of the area and to the land-based activities surrounding the Gulf of Cagliari. The statistical analysis identifies two main intervals (i.e., the years 1907–1986 and 1986–2013) that are typified by different benthic foraminiferal assemblages and diversity values. Accordingly, the increases in organic matter content and both organic and inorganic contaminants are well mirrored by a major drop in foraminiferal diversity after 1973 and a major foraminiferal turnover after 1989. The composition of the benthic foraminiferal assemblages in the uppermost part of the core (i.e., 1989–2013) might suggest a lowering of the oxygen availability at the seafloor. These changes might be related to the increase in organic matter and the silty fraction in the same interval likely triggered by damming on land and wetland reclamation.

Land Use and Land Cover Change Study Using RS-GIS and Its Impact on Biodiversity: Study from Arunachal Pradesh, India

This study aims to depict the intricate relationship between biophysical parameters, particularly land surface temperature (LST), and their impact on biodiversity at Itanagar Wildlife Sanctuary in Arunachal Pradesh. Focused on the consequences of anthropogenic activities, our research assesses changes in forest cover using Landsat images from 1990, 2003, and 2019. Utilizing satellite data, calculation of indices such as Normalized Difference Vegetation Index (NDVI), Normalized Difference Built-up Index (NDBI), Normalized Difference Water Index (NDWI), and LST were performed. Land use land cover (LULC) was determined through supervised classification, achieving accuracies of 75%, 87%, and 83% for 1990, 2003, and 2019, respectively. The analysis highlighted a substantial increase in settlement area from 9.37 km2 in 1990 to 22.86 km2 in 2019, indicative of significant urbanization impacts.Our findings reveal a pronounced positive correlation between settlement growth and elevated LST, indicating the influence of urbanization on thermal dynamics. Additionally, positive correlations were observed between LST and NDBI, while a negative correlation existed between LST and NDVI. Questionnaire-based surveys complemented remote sensing data, exposing a gradual decline in wildlife sightings, diminishing populations of rare plant species, and the proliferation of invasive plants within and around the Wildlife Sanctuary since 1990.This research underscores the substantial impact of urbanization on the biodiversity of the Itanagar Wildlife Sanctuary. Positive correlations between settlement growth, LST, and biophysical parameters emphasize the urgency for targeted conservation strategies. The decline in wildlife sightings and the encroachment of invasive species underscore the need for proactive measures to balance biodiversity conservation with the challenges posed by urban development. Our integrated approach, combining remote sensing, survey data, and ecological indices, offers valuable insights for sustainable management and conservation efforts in similar habitats globally.

Insights into the effects of anthropogenic activities on oil reservoir microbiome and metabolic potential

Microbial communities have long been observed in oil reservoirs, where the subsurface conditions are major drivers shaping their structure and functions. Furthermore, anthropogenic activities such as water flooding during oil production can affect microbial activities and community compositions in oil reservoirs through the injection of recycled produced water, often associated with biocides. However, it is still unclear to what extent the introduced chemicals and microbes influence the metabolic potential of the subsurface microbiome. Here we investigated an onshore oilfield in Germany (Field A) that undergoes secondary oil production along with biocide treatment to prevent souring and microbially induced corrosion (MIC). With the integrated approach of 16 S rRNA gene amplicon and shotgun metagenomic sequencing of water-oil samples from 4 production wells and 1 injection well, we found differences in microbial community structure and metabolic functions. In the injection water samples, amplicon sequence variants (ASVs) belonging to families such as Halanaerobiaceae, Ectothiorhodospiraceae, Hydrogenophilaceae, Halobacteroidaceae, Desulfohalobiaceae, and Methanosarcinaceae were dominant, while in the production water samples, ASVs of families such as Thermotogaceae, Nitrospiraceae, Petrotogaceae, Syntrophaceae, Methanobacteriaceae, and Thermoprotei were also dominant. The metagenomic analysis of the injection water sample revealed the presence of C1-metabolism, namely, genes involved in formaldehyde oxidation. Our analysis revealed that the microbial community structure of the production water samples diverged slightly from that of injection water samples. Additionally, a metabolic potential for oxidizing the applied biocide clearly occurred in the injection water samples indicating an adaptation and buildup of degradation capacity or resistance against the added biocide.

Estimation of national sources and sinks of greenhouse gases based on satellite observations

Human-driven Greenhouse gases (GHGs) are the most significant contributor to climate change. World countries and Egypt are moving towards achieving sustainable development goals (SDGs) 2030, and 2050, to reach Net-Zero emissions. Based on satellite observations, this research assesses and monitors the GHG emissions induced by human activities in Egypt. Different satellite sensors were utilized in this study to obtain Methane (CH4), Carbon Dioxide (CO2) amounts during 2015–2022. To get a deeper insight into the effects of anthropogenic activities on CO2 and CH4 amounts, they were correlated with land use and land cover, fire incidents, and industrial activities in Egypt. Results revealed a noticeable increase in CH4 and CO2 emissions over the country with a maximum level in 2022. CO2 has a seasonal variation mode, with the highest amounts in spring reaching 0.000409 CO2/mol dry-air. As well, the high CH4 concentration fluctuates all the year-round, with a peak around 1890 ppbv in August. The high levels of GHGs mostly concentrated in the Nile Delta and Nile Valley, where most of the anthropogenic activities are existing. Fire incidents, industries, and land cover change maps showed a spatial matching with the high emission zones. However, the emissions are increasing in Egypt it does not exceed the global average. In conclusion, unmanaged human activities in Egypt increased GHGs release and affected environmental sustainability. This study attempts to better understand the ambient environment in Egypt and support the decision-makers with full insight into the GHG emission hotspots in the country to mitigate their release into the atmosphere and achieve Net-Zero emissions.

Holocene climate variability and the effect of anthropogenic activities on the vegetation landscape of western-central Mexico

Atmospheric forcings control climate variability and at the same time control vegetation distribution and forest fires during the Holocene. Paleoenvironmental studies are scarce in western Mexico, particularly those documenting vegetation change, landscape dynamics, and fire regimes. This study presents a vegetation and fire occurrence reconstruction in the Etzatlán-Magdalena paleolake, western Mexico, during the Holocene. The reconstruction relies on fossil pollen, macrocharcoal and microcharcoal analyses of a clay sediment core. In the early Holocene (10–5.8 ka), climatic conditions were humid between 10 and 9 ka, represented by cloud forest of Liquidambar, Juglans, and Betulaceae. After 9 ka Quercus forest expanded and a trend towards warm conditions was detected, associated with high fire activity, suggesting the presence of a dry forest. Fire episodes at local and regional scale had a long-term negative effect on temperate and cloud forests. In the middle Holocene (5.8–2.1 ka), temperate forest was replaced by dry forest, indicating a drier climate. In the late Holocene (2.1–0.3 ka), the expansion of disturbance taxa and the low local fires indicated an open landscape and dry conditions. Human activity was documented by an increase of Cheno-Amaranthaceae, Poaceae and microcharcoal concentration after 3.5 ka. This research provides relevant information on the vegetation dynamics in a region with a long history of human settlement.

Biological Invasions in Fresh Waters: Micropterus salmoides, an American Fish Conquering the World

Biological invasions in fresh waters cause biodiversity loss and impairment of ecosystem functioning. Many freshwater invasive species are fish, including the largemouth bass Micropterus salmoides, which is considered one of the 100 worst invasive species in the world. Fast individual growth rates, high dispersal ability, ecological tolerance, and trophic plasticity are among the characteristics contributing to its success. The negative impact of M. salmoides on littoral fish communities is believed to be mitigated by habitat structural complexity resulting from aquatic vegetation and coarse woody debris, while the main limits on its spread seem to be strong water flows and high turbidity, which impairs visual predation. Together with the human overexploitation of its potential fish antagonists, habitat alteration could result in M. salmoides having seriously detrimental effects on native biodiversity. The purpose of this study is to critically review the life history and ecology of M. salmoides, its impact on ecosystems outside North America, and the effects of anthropogenic activities on its spread. This will highlight environmental factors that favor or limit its invasive success, helping to identify management measures that might mitigate its negative effects on freshwater biodiversity.

MORPHOLOGICAL INDICATORS OF THE NARROW-CRUSTED VOLE OF THE ANTHROPOGENIC TERRITORY OF NORTH-EASTERN KAZAKHSTAN

This study delves into the intricate relationships between ecological factors, adaptation, and the effects of anthropogenic activities on small mammals in the Northeastern region of Kazakhstan. External traits, including body mass, length, tail length, ear height, and hind foot length, provide valuable insights into adaptive adjustments in response to various climatic and ecological conditions. Industrial areas reveal a reduction in average body mass, attributed to patchy vegetation and proximity to factories and roads. Size variations are closely tied to food availability, with a reduction in body size and growth rates observed in technogenic zones. Tail sizes differ by age and sex, while foot sizes tend to even out as animals mature. Notably, anthropogenic pollution has minimal impact on ear length. The heart index reflects an individual’s mobility and thermoregulation, while the liver index is influenced by food availability and energy resources. Notably, the analysis extends beyond average differences, considering the range of variability to identify increased diversity, even in ecologically challenging areas. Small mammals exhibit a high metabolic rate and limited physiological stress adaptability, yet the population demonstrates remarkable adaptation. Enlarged heart indices suggest increased locomotor activity associated with overcoming anthropogenic barriers, such as railways and highways. In addition to heart indices, liver mass calculations reflect the accumulation of energy reserves and materials for growth. The study highlights that the liver mass index of field mice in industrial zones exceeds that of the control group, indicating the impact of anthropogenic activities on these organisms. This research provides valuable insights into the intricate relationships between ecological factors, adaptation, and human influence on small mammal populations in the Northeastern region of Kazakhstan. Keywords: small mammals, narrow-crusted vole, morphophysiological indicators method, exterior signs, interior signs.

Long-term variation in nutrients in the South Yellow Sea in response to anthropogenic inputs

Based on historical data from 1976 to 2019, the effects of anthropogenic activities on long-term changes in nutrients and their ecological effects in the South Yellow Sea were investigated. The dissolved inorganic nitrogen (DIN) concentrations increased continuously from 1990 until the mid-2000s, followed by a shift from an upward trend to a downward trend. The phosphate (PO4-P) and silicate (SiO3-Si) concentrations also showed obvious interannual variations throughout the study period. The concentrations of DIN, PO4-P and SiO3-Si have decreased significantly in recent decade and more. These changes mainly resulted from the reduction in terrestrial input, while the main reason for the decrease in DIN and PO4-P concentrations is the reduction in anthropogenic input. The long-term nutrient changes in the South Yellow Sea have potential ecological impacts on green tide features.

Financial values of bushmeat and effects of anthropogenic activities on mammal’s species in the Douala-Edea National Park, Cameroon

Financial values of bushmeat and effects of anthropogenic activities on mammal’s species in the Douala-Edea National Park, Cameroon

Oxidative status of Ctenomys flamarioni (Rodentia: Ctenomyidae) in natural areas with different levels of anthropic activity in southern Brazil

Rampant urbanization in coastal environments turns areas close to the seafront into a highly impacted ecosystem, possibly affecting the health and well-being of resident animal species. The tuco-tuco Ctenomys flamarioni is an endemic and endangered subterranean mammal from southern Brazil, and the anthropic influence was considered one of the main threats to the species. In this context, the present study aimed to investigate the patterns of oxidative status of the species in natural areas with different levels of anthropogenic disturbance. We evaluated two populations of C. flamarioni, one located in an area with intense anthropogenic impact due to urbanization and tourist activity, and the other in a non-impacted area. Oxidative injury parameters (lipid peroxidation and carbonylated protein levels), and the activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, glucose 6-phosphate dehydrogenase, glutathione S-transferase and carboxylesterase were measured. Individuals inhabiting the impacted area had lower G6PDH activity and higher levels of carbonylated proteins. This combination of higher level of oxidative damage and lower antioxidant activity is an indication that the oxidative status of animals in the impacted population is possibly being affected as a consequence of anthropogenic activities in this environment. The values of the parameters obtained in the current study can be used as a reference of the oxidative state of C. flamarioni in future studies with tuco-tucos.

Hydroclimate reconstruction during the last 1000 years inferred from the mineralogical and geochemical composition of a sediment core from Lake-Azuei (Haiti)

This study aims to reconstruct the hydro-climatic variations over the last 1000 years in Haiti using mineralogical and geochemical composition of well dated lacustrine sediment core retrieved from Lake Azuei. The results show changes in sedimentological processes linked to environmental and climatic variations. The general pattern suggests a wetter Medieval Climate Anomaly (MCA), drier Little Ice Age (LIA), high climate variability during the MCA-LIA transition and more anthropogenic impacts that dominate natural climate during the Current Warm Period (CWP). The MCA period (~1000–1100 CE) thus appears marked by increase sedimentation rate supported by higher terrigenous input linked to erosive events particularly increases in precipitation. During the LIA, particularly from ~1450 to 1600 CE, there is a great variation toward a decrease of terrigenous input, which is related to a decrease on sedimentation rate and increase Mg-calcite precipitation, suggesting less precipitation and high evaporation respectively during dry climate conditions. The MCA-LIA transition (~1200–1400 CE) is characterized by variations between terrigenous input, Mg-calcite formation and organic matter deposition, which indicate succession of dry and humid conditions. The CWP (1800–2000 CE) shows a progressive increase on sedimentation rate and decrease of gray level, which indicate more organic matter sedimentation as consequence of anthropogenic activities in the surrounding basin of the lake. High-resolution gray level analysis, which reflects principally variations in terrigenous input, carbonate mineral formation and organic matter deposition, shows that the AMO, NAO, PDO and ENSO are the principal modes affecting the hydro-climatic changes in Haiti during the last millennium. In addition, temporal correlation of other Caribbean paleoclimate records with our geochemical and mineralogical data, suggests that trends observed in Lake Azuei were controlled by regional climate, likely associated with shifts in the position of the ITCZ.

Antibiotic resistance gene abundance and bacterial community composition in macroinvertebrates of an urban stream

Abstract Increase in antibiotic resistance genes (ARGs) in freshwater ecosystems as a consequence of anthropogenic activities is a matter of public health concern. Although researchers have looked at ARG abundance and the factors affecting them in biofilms, water and sediment, the role of freshwater macroinvertebrate gut microbiomes in harbouring and disseminating ARGs is unknown. In the current study, we tested whether: (a) macroinvertebrate gut microbiomes serve as hotspots of ARGs in comparison to their immediate environment, (b) functional feeding groups (FFGs) impact ARG abundance in macroinvertebrate guts, (c) bacterial community composition and ARG abundance are correlated, and (d) macroinvertebrates can be potential vectors of ARGs. Macroinvertebrates, sediment and water samples were collected from seven different sites along northeastern Ohio (U.S.A.) streams and abundances of three ARGs (sulI, sulII and tetW) were determined. Bacterial community composition also was examined for respective microbiomes and a microcosm study was designed for testing hypothesis 4. In many cases, the gut microbiome had higher relative ARG abundance (sulI and sulII) at sites along Tinker's Creek compared to the surrounding substrate and water. ARG abundances along with taxonomic differences in bacterial community composition were different among the FFGs (ARG abundance higher in omnivores). Certain bacterial taxa were significantly correlated with one or more ARGs. We did not find that freshwater macroinvertebrates can serve as vectors of ARGs (from the microcosm study). Overall, our site‐based results suggest that freshwater macroinvertebrate guts may serve as reservoirs of ARGs, differences in ARG abundance among FFGs was possibly a result of differences in bacteria ingested and gut morphophysiological conditions. Because this study indicates that macroinvertebrate guts can be potential reservoirs of ARGs, future studies can be designed to understand the role of macroinvertebrates in dissemination of ARGs in freshwater ecosystems.

Temporal variability of global potential water erosion based on an improved USLE model

Assessing spatiotemporal variation in global soil erosion is essential for identifying areas that require greater attention and management under the effects of anthropogenic activities and climate change. Soil erosion can be modelled using the universal soil loss equation (USLE), which includes rainfall erosivity (R-factor), vegetation cover (C-factor), topography (LS-factor), soil erodibility (K-factor), and management practices (P-factor). However, global soil erosion modeling faces numerous challenges, including data acquisition, calculation processes, and parameter calibration under different climatic and topographic backgrounds. Thus, we presented an improved USLE-based model using highly distributed parameters. The R-, C-, and P-factors were modified by the climate zone, country, and topography. This distributed model was applied to estimate the intensity and variations in global soil erosion from 1992 to 2015. We validated the accuracy of this model by comparing simulations with measurements from 11,439 plot years of erosion data. The results showed that i) the average global erosion rate was 5.78 t ha−1 year−1, with an increase rate of 4.26 × 10−3 t ha−1 year−1; ii) areas with significantly increasing erosion accounted for 16% of the land with water erosion, whereas those with significantly decreasing erosion accounted for 7%; and iii) areas with severe erosion included the western Ghats, Abyssinian Plateau, Brazilian Plateau, south and east of the Himalayas, and western coast of South America. Intensified erosion occurred mainly on the Amazon Plain and the northern coast of the Mediterranean. This study provides an improved water erosion prediction model and accurate information for researchers and policymakers to identify the drivers underlying changes in water erosion in different regions.

Double‐edged effects of anthropogenic activities on lake ecological dynamics in northern China: Evidence from palaeolimnology and ecosystem modelling

Abstract Climate change and anthropogenic activities mutually degraded global lake ecosystems during the Anthropocene. Nutrient mitigation via catchment management has been a constant priority for lake ecological restoration; however, the outcomes after mitigation remain uncertain. In particular, there is limited knowledge on the effects of large‐scale forest restoration and soil erosion reduction in catchments on the ecological dynamics of downstream aquatic systems. Here, we study a strategically chosen alpine lake from the Loess Plateau in northern China, which has been extensively afforested in the past decades. We present high‐resolution, multi‐proxy records to reconstruct environmental and ecological dynamics since 1960. To quantify the potential mechanisms, we combined evidence from palaeolimnological records, contemporary field observations and process‐based ecosystem modelling. We developed palaeorecord‐based proxies for water transparency, nutrient concentrations and algal composition, and applied these proxies to ecosystem modelling. Our results show that despite the concurrent decline in nutrient levels, the lake ecosystem has experienced large‐magnitude rapid shifts since 2000, characterised by unambiguously increased algae proliferation and community changes. The modelling results revealed that the reduction in soil erosion acts as a “double‐edged sword”; that is, lower external nutrient loading via soil erosion is ideal for in‐lake algae inhibition, whereas increasing light availability counteracts the reduced yet still sufficient nutrient concentrations and, ultimately, promotes temporary algal proliferation via extended habitats and intensive photosynthesis. Intriguingly, lake warming plays a secondary role in driving these ecological dynamics. Our results emphasised the unexpected algal proliferation when the nutrient level declined in lake ecosystems; thus, other compound factors, including water transparency and climate warming, need to be incorporated for reliable prediction and effective restoration. A multi‐disciplinary approach integrating palaeorecords as ecological indicators and process‐based ecosystem modelling holds great potential for investigating long‐term lake ecological dynamics in the context of rapid global changes.

Riverine inputs, spatiotemporal variations, and potential sources of phthalate esters transported into the Bohai Sea from an urban river in northern China

The effects of anthropogenic activities on pollutant transport and inputs to the sea remain unclear. This study aimed to evaluate the impacts of sewage discharge and dam interception on riverine inputs, spatiotemporal variations, and potential sources of phthalate esters (PAEs) throughout the Haihe River, one of the largest rivers in northern China. Based on seasonal observations, the yearly inputs of the total concentrations of 24 PAE species (Σ24PAEs) from the Haihe River to the adjacent Bohai Sea were in the range of 5.28–19.52 tons, a considerable amount compared with those of other large rivers worldwide. The value of Σ24PAEs in the water column ranged from 1.17 to 15.46 μg/L and showed the following overall seasonal pattern: normal season > wet season > dry season, with dibutyl phthalate (DBP) (31.0 ± 11.9 %), di (2-ethylhexyl) phthalate (DEHP) (23.4 ± 14.1 %), and diisobutyl phthalate (DIBP) (17.2 ± 5.4 %) as the dominant components. Σ24PAEs were higher in the surface layer, slightly lower in the intermediate layer, and higher in the bottom layer. Σ24PAEs increased from the suburban section to the urban and industrial sections, which may indicate the effects of runoff, biodegradation, regional urbanization, and industrialization levels. The Erdaozha Dam intercepted 0.29–1.27 tons of Σ24PAEs inputs into the sea, but induced a substantial quantity accumulated behind the dam. The dominant sources of PAEs were the basic residential necessities (18.2–25.5 %) and industrial production (29.1–53.0 %). This study provides insights into the direct effects of sewage discharge and river dams on the inputs and variations in the PAEs entering the sea, which can be leveraged to manage and control PAEs in megacities.

A First Insight into the Microbial and Viral Communities of Comau Fjord-A Unique Human-Impacted Ecosystem in Patagonia (42∘ S).

While progress has been made in surveying the oceans to understand microbial and viral communities, the coastal ocean and, specifically, estuarine waters, where the effects of anthropogenic activity are greatest, remain partially understudied. The coastal waters of Northern Patagonia are of interest since this region experiences high-density salmon farming as well as other disturbances such as maritime transport of humans and cargo. Here, we hypothesized that viral and microbial communities from the Comau Fjord would be distinct from those collected in global surveys yet would have the distinctive features of microbes from coastal and temperate regions. We further hypothesized that microbial communities will be functionally enriched in antibiotic resistance genes (ARGs) in general and in those related to salmon farming in particular. Here, the analysis of metagenomes and viromes obtained for three surface water sites showed that the structure of the microbial communities was distinct in comparison to global surveys such as the Tara Ocean, though their composition converges with that of cosmopolitan marine microbes belonging to Proteobacteria, Bacteroidetes, and Actinobacteria. Similarly, viral communities were also divergent in structure and composition but matched known viral members from North America and the southern oceans. Microbial communities were functionally enriched in ARGs dominated by beta-lactams and tetracyclines, bacitracin, and the group macrolide-lincosamide-streptogramin (MLS) but were not different from other communities from the South Atlantic, South Pacific, and Southern Oceans. Similarly, viral communities were characterized by exhibiting protein clusters similar to those described globally (Tara Oceans Virome); however, Comau Fjord viromes displayed up to 50% uniqueness in their protein content. Altogether, our results indicate that microbial and viral communities from the Comau Fjord are a reservoir of untapped diversity and that, given the increasing anthropogenic impacts in the region, they warrant further study, specifically regarding resilience and resistance against antimicrobials and hydrocarbons.

Effects of anthropogenic activities and climate factors on the distribution of invasive alien species in China

全球变化引起的生物入侵已经严重地威胁了生物多样性分布和生态系统功能与服务. 生物入侵分布格局及其影响因素的深入研究有助于更好地预测和管理外来入侵物种, 从而有效地保护生物多样性和生态系统功能与服务. 然而, 目前尚未有研究系统地讨论不同时期人类活动与自然因子对中国外来入侵植物、外来入侵昆虫和外来入侵微生物分布格局的影响. 本研究基于最近出版的外来入侵生物相关资料, 首先描述了3个外来入侵类群在我国的省级分布格局. 然后利用单因素普通最小二乘法模型和空间自回归模型探讨了不同时期人类活动和自然因素对这些分布格局的影响. 结果表明3个外来入侵类群丰富度在我国各省份的分布呈现相似的格局, 即东南偏多, 西北偏少; 相较于入侵植物和入侵昆虫, 入侵微生物在东北和华北的丰富度也较高. 2000年的国内生产总值是影响3个分类群丰富度最大的人类活动指标, 且均呈显著正相关关系. 在自然因子中, 年均温和年降水对入侵植物丰富度和入侵昆虫丰富度解释率也较高, 且呈显著正相关关系, 但对入侵微生物丰富度影响不显著. 值得一提的是, 即使在控制自然因子的影响后, 2000年的国内生产总值依然是对3个分类群丰富度影响最大的因子. 研究结果表明尽管我国东南地区温湿的气候有利于外来入侵生物的生存和扩散, 该区域大量的社会经济活动也是促进外来生物入侵的重要因素. 因此, 未来我国在开展对外贸易与发展经济的同时, 应该更加重视对外来入侵生物的管控.