Search Results (125)

Tidal freshwater forested wetlands (TFFWs) typically occur at the interface between upriver non-tidal forests and downstream tidal marshes. Due to their location, these forests are susceptible to estuarine and riverine influences, notably periodic saltwater intrusion events. The Mobile-Tensaw (MT) River Delta, one of the largest river deltas in the United States, features TFFWs that are understudied but threatened by sea level rise and human impacts. We surveyed 47 TFFW stands across a tidal gradient previously determined using nine stations to collect continuous water level and salinity data. Forest data were collected from 400 m² circular plots of canopy and midstory species composition, canopy tree diameter and basal area, stem density, and tree condition. Multivariate hierarchical clustering identified five distinct canopy communities (p = 0.001): Mixed Forest, Swamp Tupelo, Water Tupelo, Bald Cypress, and Bald Cypress and Mixed Tupelo. Environmental factors, such as river distance (p = 0.001) and plot elevation (p = 0.06), were related to community composition. Similar to other TFFWs along the northern Gulf of Mexico, forests closest to Mobile Bay exhibited lower basal areas, species density, diversity, and a higher proportion of visually stressed individual canopy trees compared to those in the upper tidal reach. Results indicate a strong tidal influence on forest composition, structure, and community-level responses. Full article

Spaceborne spectroscopic imaging offers the potential to improve our understanding of biodiversity and ecosystem services, particularly for challenging and rich environments like mangroves. Understanding the signals present in large volumes of high-dimensional spectroscopic observations of vegetation communities requires the characterization of seasonal phenology and response to environmental conditions. This analysis leverages both spectroscopic and phenological information to characterize vegetation communities in the Sundarban riverine mangrove forest of the Ganges–Brahmaputra delta. Parallel analyses of surface reflectance spectra from NASA’s EMIT imaging spectrometer and MODIS vegetation abundance time series (2000–2022) reveal the spectroscopic and phenological diversity of the Sundarban mangrove communities. A comparison of spectral and temporal feature spaces rendered with low-order principal components and 3D embeddings from Uniform Manifold Approximation and Projection (UMAP) reveals similar structures with multiple spectral and temporal endmembers and multiple internal amplitude continua for both EMIT reflectance and MODIS Enhanced Vegetation Index (EVI) phenology. The spectral and temporal feature spaces of the Sundarban represent independent observations sharing a common structure that is driven by the physical processes controlling tree canopy spectral properties and their temporal evolution. Spectral and phenological endmembers reside at the peripheries of the mangrove forest with multiple outward gradients in amplitude of reflectance and phenology within the forest. Longitudinal gradients of both phenology and reflectance amplitude coincide with LiDAR-derived gradients in tree canopy height and sub-canopy ground elevation, suggesting the influence of surface hydrology and sediment deposition. RGB composite maps of both linear (PC) and nonlinear (UMAP) 3D feature spaces reveal a strong contrast between the phenological and spectroscopic diversity of the eastern Sundarban and the less diverse western Sundarban. Full article

The need to find a trade-off between protecting water-related ecosystems and increasing safe water-use for human society is recognized in the 2030 Agenda of the European Union. We assess the ecological status of a riverine system in order to mitigate human impacts, considering its importance for supplying drinking water to more than 4 million users in Rome. We used an integrated approach, analyzing animal and plant communities at riverbanks and the riverbed. A macrobenthos analysis revealed a well-structured community with a good ecology for all sampling stations. The highest value was found immediately upstream and downstream of the springs collection system, while the lowest richness value was where the river collects urban wastewater. A floristic inventory showed Hemicryptophytes composing almost 45% of all species, and prevalence of Euroasiatic (35%) and Orophilous (34%) chorotypes. A positive correlation between riverbed vegetation and the quality of the benthic community was revealed, while tree height seems to have a negative trend. Our data suggest a river stretch affected by resurgence and water abstraction did not highlight irreversible alterations to the landscape. Indeed, the composition of vegetation and correlated animal communities mirrored a clinal gradient expected for an Apennine river system. Our study has the potential to improve the approach used to monitor the impacts of humans on freshwater ecosystems, aiming at preserving the integrity of the water-related landscape. Full article

Conflicts between human populations and Nile crocodiles are widespread with crocodiles posing significant threats to fisherfolk and riverine communities across r-Saharan Africa. Hundreds of deadly attacks take place annually, and mortality rates may range from 50% to 100%. Attitudes and perceptions towards crocodiles were studied using structured questionnaires among fisherfolk along the River Nile and the Sudd wetlands in South Sudan. Local communities used crocodiles for their meat and skin/leather trades. The meat is regarded to enhance longevity, sexual potency, and protection against witchcraft. Crocodiles are perceived as a main threat to lives and livelihoods as they restrict people’s freedom of movement along water bodies, attack livestock and humans, and devastate fishing equipment. To assess whether responses were influenced by the intensity of crocodile threats, published data on fatal crocodile attacks on humans and livestock were analysed using Generalised Linear Models (GLMs). This analysis indicated a direct link between the number of crocodile attacks and human attitudes. Crocodiles were generally feared and hated, and there was the agreement of the need to destroy breeding habitats. However, some attitudes were complex and nuanced as highlighted by the agreement of local communities on the need to destroy Nile Crocodile breeding habitats on the one hand and the need to establish crocodile sanctuaries as the the preferred strategy to mitigate risks and conflict on the other hand. There is a need for the creation of a crocodile sanctuary in the Sudd wetlands to minimise the risks of illegal hunting and to buffer the increasing pressure on crocodiles due to human population growth and economic upturn after the civil war. Full article

Numerous organic chemicals exist within aquatic environments, yet effectively screening and prioritizing them is a huge challenge. This study provides a comprehensive investigation into the ecological dynamics of the North Oconee River within Athens-Clarke County, Georgia, with a specific focus on the distribution of 33 identified compounds, including a prominent pesticide. The research, conducted in the riverine ecosystems proximal to the Firefly trail, employs advanced analytical techniques to elucidate potential contamination sources arising from agricultural and urban runoff. Intriguingly, the study reveals North Oconee River near the Firefly Trail as a notable site for heightened pesticide contamination, warranting a meticulous exploration of its origins. Furthermore, the investigation unveils the intricate microbial degradation processes of malathion within the North Oconee River, elucidating the pivotal role played by microbial activity in river water. The detection of degradant byproducts prompts the considerations of bioavailability and toxicity, associating potential implications for the river’s overall ecological health. Ongoing research endeavors to precisely quantify environmental risks and unravel indigenous microbial degradation pathways, presenting pivotal contributions to the scientific community’s understanding of complex riverine ecosystems. This research serves as a foundational piece in informing sustainable environmental management practices and emphasizes the urgency of comprehensive stewardship in safeguarding aquatic ecosystems. Full article

Although reclaimed water (RW) has become a promising alternative source for alleviating water shortage in arid and semiarid regions, the ecological risks it poses to the receiving water bodies remain largely unknown. Dissolved organic matter (DOM) is crucial for affecting the quality of RW and strongly influences bacterial communities (BCs) in aquatic ecosystems. In this study, we aimed to unravel the role of DOM signatures on the spatiotemporal composition of microbial communities (MCs) in a seasonally ice-sealed urban river that had been chronically replenished by RW. We found that discharging RW resulted in elevated DOM levels in the receiving river. Notably, an increase of 10% in protein-like substances was revealed. The differences between compositional characteristics of DOM and the abundance of riverine BCs between freezing and non-freezing periods were revealed. In the freezing season, humic-like components, aromaticity, and hydrophobicity of DOM were more significant, and bacterial taxa such as Bacteriodetes and Flavobacterium were increased, while Proteobacteria was decreased. Similarly, co-occurrence network analysis revealed an enhanced interplay between DOM and BCs at the same time. However, Klebsiella pneumoniae markedly decreased during the ice-sealed period. These results suggest that variations in DOM characteristics have remarkable impacts on the dynamics of aquatic BCs, which points to the need for a DOM−oriented RW quality monitoring strategy. Full article

Onchocerciasis, or river blindness, has historically been one of the most important causes of blindness worldwide, and a major cause of socio-economic disruption, particularly in sub-Saharan Africa. Its importance as a cause of morbidity and an impediment to economic development in some of the poorest countries in the world motivated the international community to implement several programs to control or eliminate this scourge. Initially, these involved reducing transmission of the causative agent Onchocerca volvulus through controlling the vector population. When ivermectin was found to be a very effective drug for treating onchocerciasis, the strategy shifted to mass drug administration (MDA) of endemic communities. In some countries, both vector control and ivermectin MDA have been used together. However, traditional vector control methods involve treating rivers in which the black fly vectors breed with insecticides, a process which is expensive, requires trained personnel to administer, and can be ecologically harmful. In this review, we discuss recent research into alternatives to riverine insecticide treatment, which are inexpensive, ecologically less harmful, and can be implemented by the affected communities themselves. These can dramatically reduce vector densities and, when combined with ivermectin MDA, can accelerate the time to elimination when compared to MDA alone. Full article

Chagas disease (CD) is a typical tropical illness caused by Trypanosoma cruzi. The objective of this study was to assess the prevalence of Chagas disease in communities in two states of the Brazilian Amazon. Data collection occurred in July in the Alto Juruá region of Acre and in December in the communities of Humaitá, Amazonas, in 2019. A total of 477 participants were included in the study. In the communities of Alto Juruá, triatomine collections and analyses of T. cruzi infection were also carried out. All confirmed cases were found in the state of Acre, resulting in a total prevalence of 1.67. Of these eight cases, seven underwent ECG, all of which were concluded as normal by the physician team’s cardiologists. Seventeen triatomine bugs, all belonging to the Rhodnius genus, were captured. The natural infection rate by T. cruzi was 25% in the Nova Cintra community and 66.67% in the Boca do Moa community (Alto Juruá). This research found that more than 1% of the studied population exhibited positive serological results for Chagas disease in the riverine communities during the study period, representing a small portion of cases among those who have not yet been diagnosed. Full article

The edaphic and environmental changes in Bujagh grasslands have led to a gradual decline in the wintering waterbird populations in the associated national park. This has particularly affected forage habitats for birds, especially migratory geese. Our aim was to identify the reasons for the loss of habitat quality by examining the structure of the plant community and the edaphic factors that have been instrumental in shifting the grass community pattern to a Rush–Rubus type along the succession route. Bujagh National Park is surrounded by marine, riverine fresh water, and lagoon habitats, and the seasonal floodings of the Sefidrud and Ushmak rivers impact the grassland area along the deltaic pathway to the Caspian Sea. We used the TWINSPAN classification function to extract plant groups and their dominant species. Subsequently, we analyzed land cover changes in the study area over two times (2010 and 2020) to identify alterations in the coverage of main plants and land uses. Following the evaluation of unconstrained ordination methods and the selection of NMDS ordination, we compared the dominant species of groups to the main edaphic predictors. The results indicated that the chemicals and heavy metals in the soil did not play a direct role in the shift from grassland to Rush–Rubus plant type. However, these elements could have a significant impact on the evolution of the structure and the competitive capability among the main dominant species of the grass group. In conclusion, the dominance of the Rush–Rubus type is likely related to other unmeasured environmental and anthropogenic factors that support and enhance their reproductive attributes and herbal proliferation in the grassland territory. Full article

The riverine region of Bayelsa State, Nigeria, faces a critical issue as the impacts of climate change, including rising sea levels, extreme weather events, and disruptions to traditional livelihoods, disproportionately affect women. This qualitative study aimed to fill a gap in understanding by exploring the nuanced ways in which these environmental challenges influence the migration decisions of women who have fled floods, remain displaced, and have opted not to return to prevent potential negative experiences linked to future flooding in the region. The research delves into the interplay between climate change, gender dynamics, and community resilience. Employing an exploratory research design with purposive and snowball sampling techniques, the study selected 51 female participants. Through 24 in-depth interviews and three focus group discussions, the research captured the nuanced experiences of women grappling with the challenges posed by climate change. Thematic analysis was applied to analyze the collected data. The study unveiled that climate change significantly shapes the migration decisions of women in the riverine area of Bayelsa State. This influence manifests through disrupted livelihoods, flooding, water scarcity, diseases and health challenges, housing insecurity, increased environmental vulnerabilities, and uncertain future prospects. These findings underscore the pressing need for gender-responsive policies and community-based strategies to address the complex interplay between climate change impacts and women’s migration experiences. Full article

Rabies, caused by the Lyssavirus genus, is a highly lethal zoonotic disease transmitted by animals such as bats and domestic and wild carnivores to humans, claiming nearly 100% of lives. In Brazil, recent evidence suggests an increasing role of bats in human deaths from rabies, particularly in the Amazon region. This neglected tropical disease disproportionately affects impoverished and vulnerable populations in rural areas, where approximately 80% of human cases are concentrated. This article presents research conducted in riverine communities of the Tapajós/Arapiuns Extractive Reserve in Brazil to combat rabies in September 2022. The study adopted a participatory and collaborative approach, involving community members, healthcare professionals, and educators. Prioritizing proactive interventions, the health team administered prophylactic vaccinations to 30 individuals residing in communities exposed to the Lyssavirus. Educational activities focused on dispelling myths and raising awareness about preventive measures, with 100% of individuals reporting prior doubts about the disease, emphasizing the essential nature of the clarification, especially regarding preventive aspects. This study underscores the importance of community involvement, personalized interventions, and ongoing education to effectively combat rabies. By reinforcing public health policies and promoting health education, we can empower communities to take proactive measures in rabies prevention, leading to a reduction in incidence and an improvement in quality of life. Full article

Erosion presents a significant challenge to coastlines worldwide, and the Ilaje area in Nigeria’s Niger Delta is no different. Aggressive flooding along this shoreline has led to property damage, economic disruption, and a looming threat to the survival of riverine communities in the region. This study presents a comprehensive analysis of spatial and temporal changes in the Ilaje coastal area of Ondo state from 1986 to 2020. The analysis utilized the SCE, EPR, and LRR methods to examine shoreline changes. Additionally, spatial digitization was performed for Ayetoro, a highly susceptible coastal community, spanning from 2008 to 2023. The results indicate that approximately 86% of the coastline experienced erosion, while the remaining 14% underwent accretion. Notably, the western and central sections of the coastline emerged as the areas most vulnerable to erosion. Ayetoro, situated centrally, faces dire circumstances. The interplay of natural geomorphic processes and human activities played a role in driving these changes. Beyond the immediate physical alterations, erosion has reverberated through the local ecosystems, livelihoods, and infrastructure, posing risks to numerous communities. This study emphasizes the need for urgent actions through integrated coastal zone management (ICZM) strategies to promote coastal stability in the region. The results of the study further provide valuable insights into the need for coastal managers and planners to regularly assess the state of the coastline and proactively proffer suitable solutions to reduce rampant coastal degradation. Full article

The present study is the first structured attempt to analyze the species composition and distribution of freshwater invertebrates in the lakes, streams, and rivers of the Shantar Islands and to compare the diversity of the hydrobiont fauna of the archipelago and the continental part of Khabarovsk Krai on the basis of the original and literature data. The research revealed 57 zooplanktonic, 47 meiobenthic, and 142 macrobenthic taxa in the waters of the island and the adjacent continental areas. Different patterns of variability in the species richness, abundance, and the community structure are observed for different groups of hydrobionts along the salinity gradient in the unique, brackish Lake Bolshoe. Zooplankton show no directional variability, reaching a maximum in a frontal zone where riverine and brackish water mix. Meiobenthos show the highest diversity in the most saline zone of the lake, where marine species are abundant. The characteristics of the macrozoobenthos gradually increase with the salinity of the lake, with a dramatic change in the dominance structure at the critical salinity threshold, where amphibiotic insects, dominant in the desalinated water zone, are replaced by amphipods. Latitudinal variability in species richness and biogeographic structure of the fauna are closely related for different groups of freshwater invertebrates. A smooth decline in species richness from southern to northern areas was observed when comparing the faunas of the Shantar water bodies with those located to the south. This trend is shown for amphibiotic insects and microcrustaceans and is most pronounced for mollusks. The fauna of the Shantar Islands is predominantly represented by species with a wide Palaearctic, Holarctic, and cosmopolitan range, with a small proportion of species restricted to the Arctic zone of Eurasia or specific to Eastern Siberia and the Far East. Only three brackish water species have a Beringian type of distribution. The assemblage structures of the zooplankton and meiobenthos communities of continental coastal and island lakes do not greatly differ. On the contrary, brackish communities are clearly distinct from the others. The taxonomic composition of macroinvertebrates differed significantly between the islands and the mainland. Full article

Among the impacts of dam construction on river ecosystem, runoff regulation and habitat fragmentation are the two major concerns. Herein, the response characteristics of phytoplankton communities to reservoir impoundment and dam interception were explored by taking Manjiang and Songjiang rivers, where a man-made engineering project was constructed, and the natural stretches located in the up-streams as the research objects. The results obtained revealed that the compositions of phytoplankton communities, collected from the 21 sampling sites in the riverine wetlands of reservoir stretch, flow-reduced stretch, and natural stretch, were dissimilar. The communities of phytoplankton were clustered into three groups. The co-occurrence network analysis indicated that the interspecific relationship structures of phytoplankton communities of each group were different. The indicator species Chlamydomonas ovalis, Synedra acus, and Chlamydomonas globosa, belonged to the Reservoir Wetlands Group, Diatoma vulgare, Fragilaria ca pucina, and Meridion circulare belonged to the Flow-reduced Wetlands Group, and Ceratoneis arcus and Treubaria crassispina belonged to the Natural Wetlands Group. The functional group L0 was the absolute dominant group in all three groups of the riverine wetlands, but a discrepancy was that the proportions of functional group X2 and functional group C in the Reservoir Wetlands Group were remarkably higher, while the proportion of functional group MP in the Flow-reduced Wetlands Group was noticeably higher. By assessing the status of the phytoplankton community composition and the functional group structure, we concluded that current velocity and water depth were crucial influencing factors, and the functional group structure based on the classification of livable water could be applied as a good indication for demonstrating phytoplankton community succession. Full article

Riparian predatory arthropods represent one of the main trophic links between lotic and terrestrial ecosystems along riverine landscapes. The use of the trait-based approach promises to enhance our understanding of how these predatory communities interact with their environment through their response to various drivers of change and through their trophic interactions. We reviewed the scientific literature focused on the interaction between drivers of community change (natural and anthropogenic) and the functional traits and functional diversity components that characterize riparian ground beetles and spiders and, ultimately, on their role as cross-ecosystem trophic links. We highlight land use changes and river regulations as the strongest drivers that change the communities we study, often through various interacting mechanisms that favor the replacement of riparian specialists with generalist species, thus altering aquatic–terrestrial connectivity and the resilience of riverine arthropod consumers. Tropical regions and traits related to community responses to extreme climatic events (e.g., submersion tolerance and desiccation resistance) are less studied, while inconsistent patterns are noticed for well-studied traits, especially for spiders (e.g., their feeding preference response to aquatic subsidy availability and their body size response to flooding and bank hydrological connectivity). Future research should focus on the aforementioned drivers and knowledge gaps, along with the functional diversity changes in predatory arthropod communities along environmental and anthropogenic impact gradients, in order to improve riparian conservation. Full article