Search Results (112)

The clarification of community assembly mechanisms in benthic macroinvertebrates and their respective contributions to the development of beta diversity is a fundamental concern in aquatic ecology. Nonetheless, the intrinsic complexity of community alterations and their non-linear reactions to gradients of explanatory variables present considerable obstacles to measuring the determinants of beta diversity. Fifty sampling points were set up along the major rivers of the Yellow River Irrigation Area (YRIA), the Central Arid Zone (CAZ), and the Southern Mountainous Area (SMA) in Ningxia in April, July, and October 2023. The findings demonstrate that the optimal parameter-based geographical detector (OPGD) model identified a 3000 m circular buffer as the spatial scale at which landscape structure most significantly influences water quality. A degradation in water quality presumably results in diminished differences in species composition among communities. The Sørensen index was determined to be more appropriate for this investigation, and the total beta diversity of the communities was relatively high (β_SOR ≥ 0.82), with no identifiable nested spatial patterns detected. Except in the YRIA, environmental variability contributed more significantly to the variance in beta diversity than spatial factors, and deterministic mechanisms dominated the community assembly of benthic macroinvertebrates across all three months. To improve biodiversity and aquatic ecosystem health, the study region should optimize its landscape structure by reducing the amount of bare land and increasing the percentage of forest land within buffer zones. Additionally, a multi-site conservation strategy should be put into place. Full article

The Ghris watershed in southern Morocco is a significant ecological and agricultural area. However, due to the current impacts of climate change, farming activities, and pollution, data on its quality and biological importance need to be updated. Therefore, this study aimed to evaluate the physico-chemical and biological quality of surface water in the Ghris River. The Water Quality Index (WQI) and the Iberian Biological Monitoring Working Group (IBMWP) index were used to assess water quality along four sampling sites in 2024. The collected data were analyzed with descriptive and multivariate statistics. In total, 424 benthic macroinvertebrates belonging to seven orders were identified in the surface waters of the Ghris basin. These microfauna were significantly variable among the studied sites (p < 0.05). Station S4 is significantly rich in species, including seven orders and nine families of macroinvertebrates, followed by Station S2, with seven orders and eight families. Stations S3 and S1 showed less species diversity, with three orders and one family, respectively. The Insecta comprised 95.9% of the abundance, while the Crustacea constituted just 4.1%. The physico-chemical parameters significantly surpassed (p < 0.05) the specified norms of surface water in Morocco. This indicates a decline in the water quality of the studied sites. The findings of the principal component analysis (PCA) demonstrate that the top two axes explain 87% of the cumulative variation in the data. Stations 2 and 3 are closely associated with high concentrations of pollutants, notably Cl⁻, SO₄²⁻, NO₃⁻, and K⁺ ions. Dissolved oxygen (DO) showed a slight correlation with S2 and S3, while S4 was characterized by high COD and PO₄ concentrations, low levels of mineral components (except Cl⁻), and average temperature conditions. Bioindication scores for macroinvertebrate groups ranging from 1 to 10 enabled the assessment of pollution’s influence on aquatic biodiversity. The IBMWP biotic index indicated discrepancies in water quality across the sites. This study gives the first insight and updated data on the biological and chemical quality of surface water in the Ghris River and the entire aquatic ecosystem in southeast Morocco. These data are proposed as a reference for North African and Southern European rivers. However, more investigations are needed to evaluate the impacts of farming, mining, and urbanization on the surface and ground waters in the study zone. Similarly, it is vital to carry out additional research in arid and semi-arid zones since there is a paucity of understanding regarding taxonomic and functional diversity, as well as the physico-chemical factors impacting water quality. Full article

Intensive forestry, particularly the establishment of monospecific plantations with exotic species, can deeply impact the ecological functioning of forest streams, where riparian leaf litter is the primary source of energy. In this study, we investigated the effects of Eucalyptus globulus afforestation on macroinvertebrate communities in 20 streams in Galicia (NW Spain) with varying levels of accumulated eucalypt leaf litter. Sampling was done in autumn 2020 and spring 2021. In autumn, six streams had leaf litter composed of >50% of eucalypt leaves, a proportion that increased to 12 streams in spring. A total of 24,705 individuals were found in autumn and 12,529 in spring, belonging to 125 taxa. Although some taxa decreased their abundance with an increase in the proportion of eucalypt litter, variability in overall macroinvertebrate abundance was mainly explained by season, stream flow, and water temperature. However, species richness and diversity were significantly lower in streams mainly subsided by Eucalyptus litter compared to those dominated by native riparian vegetation. Macroinvertebrate abundance, richness, and diversity peaked in autumn, coinciding with the influx of deciduous litterfall and lower proportion of eucalypt litter. The lower quality, low-nutrient content, and presence of feeding deterrents in Eucalyptus leaf litter compared to native deciduous tree species likely drive these observed patterns, underscoring the importance of preserving native riparian forests to sustain stream biodiversity, even in managed landscapes dominated by Eucalyptus plantations. Full article

The High Andean region of Peru, characterized by a complex orography, has unique and highly biodiverse ecosystems. This region has several headwater basins that play a critical role in the hydrological cycle, providing diverse ecosystem services essential to sustain biodiversity and supply water to human communities. Despite the importance of this region, it faces significant human intervention, particularly mining activities, which affect basin headwaters and jeopardize water security. This study aimed to calibrate the Biological Monitoring Working Party (BMWP) index to evaluate water quality in High Andean rivers in Peru affected by mining activities, using aquatic macroinvertebrates as bioindicators. We used a 15-year dataset (2008 to 2023) from three headwater basins in the High Andean region; this dataset included physicochemical water quality parameters, trace metals, and aquatic macroinvertebrates. The BMWP was calibrated for the High Andean region of Peru with this dataset (BMWP/PeIAZIM); afterward, it was validated to assess water quality in an area influenced by mining activities in this region. The results allowed us to differentiate between aquatic macroinvertebrate families tolerant to mining pollution and highly sensitive families. The sites heavily affected by mining activity returned very low BMWP/PeIAZIM scores; sites with no mining impact had the highest scores. These findings indicate that the calibrated index can be used for water resource management in the High Andean region, contributing to the conservation of its ecosystems. Full article

Freshwater macroinvertebrates, often used as indicators of environmental quality for freshwater ecosystems, may be compromised by microplastics (MPs). We investigated MPs occurring in benthic filter feeder, predator, and grazer macroinvertebrates collected from the catchment-independent but adjacent Olifants and Sabie rivers of Kruger National Park as duplicates. We counted 369 MPs in 376 organisms (1.0 n/organism) with a mean of 8.8 n/organism, 8.5 n/organism, and 0.16 n/organism in filter feeders, predators, and grazers, respectively. Based on MP colour, size, and morphotype, significant differences in proportional compositions between predatorial macroinvertebrates and all other macroinvertebrates in both rivers preclude predatorial macroinvertebrates as a proxy indicator for the other macroinvertebrates. Proportional compositions of MP characteristics in macroinvertebrates differed in all respects between the two adjacent rivers, except for one aspect. Microplastic morphotypes occurred in equal proportions in macroinvertebrates of both rivers, suggesting biological selection based on morphotype but not MP colour or size. We found little evidence of trophic transfer between feeding guilds. Of the six polymer types observed (n = 50), butyl and chlorobutyl dominated. Waste mismanagement, single-use plastics, inefficient wastewater treatment plants, mining, and road transportation may be the major MP pollution sources that need mitigation. Microplastics in freshwater ecosystems of nature conservation areas need more attention due to high biodiversity that may be exposed. Full article

Understanding the contribution of macroinvertebrate diversity indices to community stability in urban rivers is critical for developing more effective strategies to manage and conserve the ecological health of urban rivers and to maintain sustainable regional economic and social development. However, knowledge regarding the relationship between environmental factors, multidimensional biodiversity, and community stability in urban rivers remains limited. In this study, we investigated the relationships among macroinvertebrate multidimensional diversity, secondary productivity-to-biomass ratio (SP/B), and average variation degree (AVD) in a typical urban river—the North Canal River basin in Beijing—to identify which biodiversity metric best indicates community stability. Macroinvertebrates were extensively sampled from September to October 2020 in the North Canal River basin (BYH), a typical urban river in Beijing. We comparatively analyzed the spatial variation in different types of diversity—species diversity (SD), functional diversity (FD), and phylogenetic diversity (PD)—as well as SP/B and AVD between the upstream and midstream–downstream reaches of the river under varying degrees of urbanization and human disturbance. Partial Least Squares Structural Equation Modeling (PLS-SEM) was used to assess the relationships among multidimensional diversity, SP/B, and AVD. The results showed that upstream environmental factors and diversity indices together explained 52.9% and 52.0% of the variance in SP/B and AVD, respectively, while midstream–downstream factors explained 65.9% and 84.2%, respectively. These findings suggest that both SP/B and AVD are suitable indicators for examining the relationships between macroinvertebrate community stability, diversity indices, and environmental factors in the BYH. In the upstream region, total phosphorus (TP), FD, and PD were more indicative of SP/B in the central urban area, while SD and PD were more indicative of AVD. In contrast, in the midstream–downstream suburban areas, dissolved oxygen (DO), SD, and PD were more indicative of SP/B, while FD and PD were more indicative of AVD. These findings demonstrate that PD is a stronger indicator of both SP/B and AVD under varying anthropogenic disturbances and environmental conditions. The PLS-SEM results also indicated differences in the specific effects of FD and SD on community stability across the upstream and midstream–downstream sections, as well as differences in the direct effects of environmental factors such as TP and DO. These results suggest that PD is more sensitive than FD and SD in detecting the impacts of anthropogenic disturbances and environmental fluctuations on macroinvertebrate community stability in urban rivers. Our study provides evidence that PD outperforms FD and SD in predicting macroinvertebrate community stability in urban river ecosystems and that the combined use of SP/B and AVD better reveals the complex interactions between biodiversity and environmental factors influencing community stability. This combination can thus enhance our understanding of how biodiversity affects macroinvertebrate community stability in urban rivers. Full article

The present study aimed to characterize the benthic macroinvertebrate community of the Jabal Ali Marine Sanctuary (JAMS), the sole marine protected area in the Emirate of Dubai, during the summer and winter seasons of 2017. Limited research on the biological quality of the JAMS prompted this investigation, which involved 10 sampling stations to assess macroinvertebrate diversity and community composition in relation to abiotic factors such as sediment granulometry, trace metals, salinity, and temperature. Collected sediment samples were analyzed for macroinfauna, and their abundance was measured, revealing an average abundance of 2150 ind/m² in summer and 2132 ind/m² in winter without a significant difference between both seasons. Univariate indices, including the Margalef diversity index and Pielou evenness index, indicate a range of diversity values across sampling sites. Community composition was assessed through SIMPROF and Bray–Curtis similarity clustering, further elucidating the relationship between community structures and environmental gradients. The dominant macroinvertebrate species varied across seasons and stations, providing insights into seasonal variations in community dynamics. These findings contribute to the understanding of benthic community structures and biodiversity in the JAMS and serve as a baseline for future monitoring and management efforts aimed at preserving the ecological integrity of this important marine sanctuary. Full article

This study assessed the water quality and ecological integrity of the Columbe River micro-watershed in the Ecuadorian Andes through a multidimensional approach incorporating biotic, physicochemical, and structural indices. Indices such as the Andean Biotic Index (ABI), Biological Monitoring Working Party index adapted for Colombian conditions (BMWP-Col), Fluvial Habitat Index (IHF), Riparian Quality Index adapted for Andean conditions (QBR-And), and Water Quality Index (WQI) characterized environmental quality gradients and evaluated the impact of human activities across 11 monitoring sites. Hierarchical cluster analysis classified sampling sites into three groups: less polluted (LP), moderately polluted (MP), and highly polluted (HP). HP sites showed elevated levels of biochemical oxygen demand (BOD₅), chemical oxygen demand (COD), electrical conductivity (EC), and turbidity, alongside low biotic and structural scores, indicating advanced ecological degradation. Conversely, LP sites demonstrated greater ecological integrity, despite elevated BOD₅ and COD levels across the watershed, suggesting widespread diffuse contamination. The findings identify anthropogenic activities such as livestock, agriculture, and domestic discharges as major pressures on water quality and macroinvertebrate biodiversity. Significant correlations between physicochemical parameters—including BOD₅ and EC—and declining biotic indices underscore the link between chemical water degradation and ecological fragmentation. In this context, this study highlights the critical need for comprehensive management and restoration strategies to combat pollution, safeguard relatively pristine areas, and rehabilitate the ecological integrity and connectivity of high-altitude Andean aquatic ecosystems under anthropogenic pressure. Full article

Soil biological activity and macroinvertebrate diversity are key indicators of ecosystem function in tropical landscapes. This study evaluates the effects of different land-use systems—Amazonian Chakra agroforestry (timber-based and fruit-based), cocoa monoculture, and tropical rainforest—on soil microbial respiration, enzymatic activity, and macroinvertebrate diversity in the Ecuadorian Amazon. Forest soils exhibited the highest edaphic respiration (240 ± 64.3 mg CO₂ m² ha⁻¹, p = 0.034), while agroforestry systems maintained intermediate biological activity, surpassing monocultures in microbial diversity and enzymatic function. The soil organic matter (SOM) content at a 10 cm depth was significantly higher in monocultures (19.8 ± 3.88%) than in agroforestry and forest soils (p = 0.006); however, the enzymatic activity showed greater functional responses in agroforestry and forest systems. The relationship between recorded CO₂ respiration (REC_CO₂) and basal respiration (RBC_CO₂) exhibited a non-linear trend, as revealed by LOWESS smoothing, suggesting that microbial respiration dynamics are influenced by substrate availability and enzymatic thresholds beyond simple linear predictions. These findings underscore the potential of agroforestry as a sustainable land-use strategy that enhances soil biodiversity, carbon sequestration and nutrient cycling. Implementing optimized agroforestry practices can contribute to long-term soil conservation and ecosystem resilience in tropical agroecosystems. Full article

Citizen science is increasingly utilized for environmental monitoring and educational purposes. For lotic ecosystems, this approach could be used to implement traditional methods and gain more data on local biodiversity, particularly in areas where professional monitoring is limited. This study, conducted in Italy, aimed to complement data on river macroinvertebrates collected by the Regional Environmental Protection Agency (ARPA) with additional data gained by volunteers. Our results revealed taxonomic differences between the macroinvertebrate communities of ARPA and citizen science sites. ARPA sites host 34.4% of the total biodiversity, with 22 exclusive taxa, while citizen science sites, with 6 exclusive taxa, represent 9.4% of the total gamma diversity. Compositional differences are mainly explained by taxa turnover between sites. ARPA sites, located along the main river stretches, are richer in alpha and gamma diversity, while volunteer-monitored sites, mostly in agricultural ditches, show lower richness at the local and regional scales but host some unique taxa, increasing the total biodiversity. This study supports the implementation of volunteer programs to increase the number of monitored rivers, enhancing information on macroinvertebrate diversity and distribution and generating relevant data to support decision-making and develop strategies for river conservation and ecosystem restoration at a local scale. Full article

Kelp forests are recognized as biodiversity hotspots and ecosystem engineers, while the macroinvertebrates linked with their holdfasts serve as markers of pollution and ecological and environmental change. Notwithstanding the evident ecological and economic importance of this system, no research has been undertaken in South Africa to examine the macroinvertebrate community assemblage patterns within the Ecklonia radiata holdfast, nor the mechanisms driving the observed distribution patterns. This study identified and compared the assemblage patterns of holdfast-associated macroinvertebrates across several sites using univariate and multivariate approaches, and delineated physical factors influencing invertebrate community organization. The key findings indicated that abundance exhibited little variations among sites, with Dwesa presenting the highest average abundance and Kob-Inn the lowest. Mazeppa exhibited the greatest species richness, succeeded by Dwesa and Nqabara. Beta diversity measured 0.42, with turnover and nestedness contributing equally. Xhorha and Nqabara exhibited the largest local contribution to beta diversity (LCBD) regarding turnover, whereas Mazeppa and Kob-Inn demonstrated the highest LCBD in terms of nestedness. Substantial clustering among sites was observed, with each site harbouring a distinct assemblage of macroinvertebrates. Species that discriminated the sites were Zeuxoides helleri, Cirolana venusticauda and Amphipholis squamata. Full article

The study evaluates the implementation of check dams as nature-based solutions to address soil erosion, improve sediment quality, and enhance water retention in the Urku Huayku ravine, located on the Ilaló volcano in Ecuador. Weekly water and sediment samples were analysed from 2021 to 2023. Critical parameters measured include pH, electrical conductivity, nutrient concentrations, and organic matter content. Macroinvertebrates were collected to assess biodiversity changes using the Andean Biotic Index (ABI) and the Shannon Diversity Index. Results show significant improvements: water quality remained neutral (average pH 7.06), while sediment organic matter increased from 0.2% in 2021 to 3.2% in 2023. Additionally, biodiversity improved, with a 355.6% increase in macroinvertebrate abundance. Statistical tests confirmed the positive impact of check dams on sediment and water quality. The study also identified potential areas for additional check dam installations using QGIS analysis, emphasising steep slopes as ideal locations. This study demonstrates the efficacy of check dams in the restoration of degraded ecosystems and underscores their pivotal role in climate change mitigation. Through the enhanced storage of sediment organic matter, check dams facilitated the capture of approximately 58% of carbon. Additionally, they contributed to improved biodiversity. Further research is recommended to optimise dam placement and explore additional biodiversity indicators in Andes Mountain water bodies over 3000 m above sea level. Full article

Benthic macroinvertebrates are crucial to the health of river ecosystems. However, their conservation status is often overlooked. Due to their limited mobility and sensitivity to habitat changes, their survival is threatened. Given the current lack of research on their value composition and evaluation, this study refers to the total economic value (TEV) framework to preliminarily construct a systematic evaluation framework for freshwater benthic macroinvertebrates. Through field surveys, questionnaires, and market survey data, the value composition of benthic macroinvertebrates in the Tuojiang River Basin of Chengdu was systematically clarified. The total value was monetized using methods such as the market price method, substitute market method, and simulated market method. The main conclusions are as follows: (1) The biodiversity value of benthic macroinvertebrates in the study area ranges from 6.36 × 10⁸ to 12.76 × 10⁸ CNY/a, accounting for 0.17–0.34% of the region’s 2019 GDP. The various values in order of proportion are as follows: non-use value > direct service value > Direct Material value > indirect use value. This indicates that this biological group has enormous potential value and significant conservation importance. (2) The proportions of the value amounts of various species in the total value differ. The proportions of Viviparidae, Odonata, Ephemeroptera, and Palaemonidae are relatively high, reaching 9.8–23.8%. The proportions of Atyidae, Semisulcospiridae, and Bithyniidae are about 5%. The proportions of Unionidae, Corbiculidae, and Aillpullaridae are less than 3%. These differences are mainly influenced by factors such as species population numbers in the region, public value perception, aesthetic preferences, and dietary habits. This evaluation framework scientifically and comprehensively assesses the biodiversity value of regional benthic macroinvertebrates, providing a reference for the value assessment of other biological groups within the region and offering a scientific basis for the conservation and sustainable utilization of the target biological groups. Full article

Deep learning models, known as convolutional neural networks (CNNs), have paved the way for reliable automated image recognition. These models are increasingly being applied in research on freshwater biodiversity, aiming to enhance efficiency and taxonomic resolution in biomonitoring. However, insufficient or imbalanced datasets remain a significant bottleneck for creating high-precision classifiers. The highly imbalanced data, where some species are rare and others are common, are typical of the composition of most benthic communities. In this study, a series of CNN models was built using 33 species of aquatic insects, with datasets ranging from 10 to 80 individuals, to determine the optimal number of individuals each class should have to build a high-precision classifier. We also consider the effect of class imbalance in the training dataset and the use of oversampling technique. The results showed that a robust model with acceptable accuracy (99.45%) was achieved with at least 30 individuals per class. A strongly imbalanced dataset caused an approximately 2% decrease in classification accuracy, while a moderately imbalanced dataset had no significant effect. The application of the oversampling technique enhanced in 1.88% the accuracy of strongly imbalanced models. These findings can help effectively tailor future aquatic macroinvertebrate training datasets. Full article

Salt marshes are vital coastal ecosystems, increasingly threatened by rising sea level and human pressures, that provide essential services, including coastal protection, habitat support, and carbon sequestration. This study examines the effectiveness of different eco-engineering structures in restoring salt marshes in the Mondego Estuary, Portugal, by assessing their impacts on benthic macroinvertebrate communities as bioindicators of ecosystem health. The experimental design included five experimental cells: wood palisade (Fence), geotextile fabric (Geotextile), geotextile bags filled with sand (Bags), a cell with autochthonous vegetation (Plants), and a Control cell with bare soil. Monitoring took place from 2019 to 2021, with both before and after intervention sampling to evaluate species composition, biomass, and density. Key ecological indices, such as the AZTI’s Marine Biotic Index (AMBI), Shannon-Wiener Diversity, and Pielou’s Evenness, were calculated alongside measurements of environmental variables. The results indicated minimal impacts on biodiversity, with observed variations primarily attributed to seasonal dynamics. While the wood palisade enhanced species richness and density, geotextile provided better community stability. The findings emphasize the importance of long-term monitoring, stakeholder engagement, and sustainable use of materials to optimize restoration efforts and better inform coastal management strategies in the face of climate change. Full article