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The Water Framework Directive (WFD) requires member states to routinely assess the river ecological status using community-based indices. However, there is still a lack of published WFD-compliant methods for the French West Indies, especially using diatom-based indices. Martinique and Guadeloupe exhibit diverse landscapes shaped by their complex geological history and tropical climatic conditions. These strong particularities make the existing indices developed for the European mainland unusable. Based on diatom sampling from to 2013 (607 samples) and through multivariate analyses, we developed the Indice Diatomique des Antilles (IDA). We first identified the key abiotic factors influencing diatom communities on both islands, and then characterized taxon sensitivity by considering their presence probability along a pressure gradient.. The index was based on the presence and relative abundance of these taxa in each sample. The last step consisted of using new data from the 2014–2022 sampling surveys (457 samples) as a validation dataset to verify IDA accuracy. Our results suggest that the IDA methodology is well designed to assess the ecological status of rivers in the West Indies. [ABSTRACT FROM AUTHOR]

The ecological quality status (EcoQS) of Vellar and Uppanar estuaries (Southeast coast of India) has been monitored monthly, using a combination of foraminiferal (Foram Stress Index: FSI and exp(H'bc) indices and abiotic (Pollution Load Index: PLI, Dissolved Oxygen: DO, and Total Organic Carbon: TOC) parameters. The Uppanar Estuary shows relatively higher values of PLI and TOC and lower DO values than Vellar Estuary. The highest value of TOC and PLI are recorded during the monsoon season. These variations are well mirrored by the change in exp(H'bc) and FSI. The lowest values of exp(H'bc) are observed with the monsoon season and could be ascribed by an overall reduction of salinity, and to the highest level of TOC and PLI in response to enhanced river discharge. The FSI also exhibits great variability with significant higher values in the Vellar Estuary than in the Uppanar Estuary. The EcoQS evaluated by a combination of pollution- (i.e., PLI, TOC and DO) and foraminiferal-based [i.e., FSI and exp(H'bc)] indices are highly consistent (73.4%). The most frequent disagreement among indices is mostly associated to Uppanar Estuary and, particularly, in the inner stations. This difference might be related to a time-lag response of benthic foraminifera in terms of diversity and assemblages' compositions as well as of the pollution indicators in response to enhanced riverine input. This study further supports the application of foraminiferal-based indices in EcoQS assessment in transitional environments including tropical Indian estuaries. It also fills the gap of knowledge by providing a seasonal perspective on the variation of EcoQS based on a monthly-scale sampling. [ABSTRACT FROM AUTHOR]

Nematodes play a key role in ecological environments. Biotic indices based on soil nematode community are effectively used for assessing soil health status. This work represents the opportunity to investigate three different management practices continuously maintained for 40 or more decades on soils with the same geological origin. This unique feature allows us to reduce variables and link biotic with abiotic factors. Therefore, the nematode communities of three neighboring volcanic soils under different managements were examined. The maximum values in soil biodiversity were found in the forest environment in which all the trophic groups were detected and well balanced. Instead, in permanent grassing and carnation crop greenhouse (CG), biodiversity indices progressively decreased with the intensification of agricultural practices. Furthermore, CG showed a stronger dominance of a specific plant-parasitic nematode identified as Heterodera daverti. Nematode indicators demonstrated that changes in the nematode community gradually varied from anthropic to natural environments whereas soil properties were feebly correlated to nematode community indicators. In conclusion, we demonstrated that biodiversity and ecological indices applied to the soil nematode community are effective at detecting alterations due to anthropogenic impact. Nematodes seem to be susceptible to perceiving the soil dynamics. [ABSTRACT FROM AUTHOR]

As bioindicators, benthic macroinvertebrates are often used to assess stream quality. Based on standard hydrobiological study techniques, the physicochemical and biological health status of the Missolé stream was assessed. Waters of the Missolé stream were found to be slightly acidic (pH: 6.23–6.26) and well-oxygenated (O2: 69.80–76.80%), with low values of temperature (T°: 23.60–24° C), turbidity (49.40–88.40 FTU) and mineralized ions (NH4+: 0–1.19 mg/L; NO2-: 0–1.61 mg/L; NO3-: 0.02–6.80 mg/L). Concerning aquatic invertebrate communities, a total of 489 individuals, grouped in two classes, eight orders and 35 families, all belonging to the phylum Arthropoda, were collected and identified. The class of Insecta was the most diversified, with seven orders and 32 families, while that of Crustacea had only one order and three families. Overall, Insecta accounted for 52.35% of the total abundance, and Decapod Crustacea was 47.65%. The three predominant families were Palaemonidae, Dytiscidae and Atyidae. Shannon and Weaver (H’) and Piélou’s evenness (J) indices were high at all stations and showed a slight decrease from upstream to downstream. In the same vein, the Hilsenhoff Biotic Index (HBI) classified the water quality of the Missolé stream as medium. Overall, this suburban aquatic ecosystem offers moderately favorable living conditions for aquatic biota.

This study was carried out to determine water quality of the Kum Stream and to compare the performance of the Saprobe Index (SI), several modifications of Biological Monitoring Working Party (BMWP), several modifications of Average Score Per Taxon (ASPT), Belgian Biotic Index (BBI), Family Biotic Index (FBI), EPT-Taxa [%], Simpson's (SDI), Shannon-Wiener (SWDI) and Margalef (MDI) diversity indices. Six sampling stations were determined and the samplings were carried out seasonally. Biotic and diversity indices based on benthic macroinvertebrates have been applied using Asterics software. Pearson's based correlations were applied to the indices in order to determine the proper biotic indices. A total of 37 taxa which belong to Gastropoda, Oligochaeta, Crustacea and Insecta were detected. The dominant group of the benthic macroinvertebrates was Insecta with 26 taxa. According to the result of ANOSIM (Analysis of Similarity); no statistically significant difference was found between the seasonal distributions of the species (p = 0.267; R: 0.038). According to the MANOVA (Multivariate Analysis of Variance) result, the seasons didn't show a significant difference on the linear combination with environmental variables (p = 0.138 > 0.05). According to the results of CCA (Canonical Correlation Analysis), it was determined that the groups known for their sensitivity to pollution showed a positive correlation with the DO and pH variables, while the groups with high tolerance levels and containing many species as pollution indicators showed a positive correlation with the temperature, TU and EC variables. As a result of this research, the water quality of the Kum Stream was determined as polluted. BBI, ASPT and BMWP indices were more proper than SI and FBI indices to determine the water quality of the Kum Stream. [ABSTRACT FROM AUTHOR]

The Yalvaç Stream is one of the important sources feeding Lake Eğirdir, the second largest freshwater lake in Turkey. Determining the pollution of the stream used for drinking water and agricultural irrigation is important not only for the continuation of the usability of water, but also for determining the pollution load it carries to Lake Eğirdir. In addition, the macrozoobenthic invertebrate fauna of the stream was revealed in the study. The study was carried out between April 2022 and January 2023, and water and macrozoobenthic invertebrate samples were taken from six stations seasonally. Belgian Biotic Index, BMWP (original and Spanish versions), and species diversity indices were applied for determining the water quality by using the ASTERICS software program. Physicochemical water quality assessment made according to the Türkiye Surface Water Quality Regulation. As a result, a total of 49 taxa were detected: three taxa from Gastropoda, two taxa from Hirudinea, one taxon from Malacostraca, and 43 taxa from Insecta. Stations were clustered by using UPGMA based on organisms. Station 6 was the most different one for the macrozoobenthic invertebrates. The lowest species diversity values were also found at this station. Physicochemical parameters and biotic indices showed that while the first three stations were in water quality class I, there was a decrease in the water quality of the other stations. The reasons for the decrease in water quality are due to domestic and agricultural wastes and livestock activities. Additionally, all of the identified taxa were reported as new records for this stream. [ABSTRACT FROM AUTHOR]

One of the key landscapes on earth are the wetland ecosystems which are extremely crucial for the sustenance of various ecological realms as they provide immense ecosystem services to them. From serving impressive hosts to many organisms, particularly migratory birds, and successfully aiding in useful interactions between various biotic and abiotic components, wetlands have a remarkable repute. It has been a matter of only few decades that interaction of man with wetlands has resulted in severe degradation of these ecological repositories. Similar is the case of Pargwal wetland of lower Shivalik, located about 5 km from the international border in Akhnoor tehsil of Jammu and Kashmir division. Continuous interference from the human habitation, encroachment of wetland area, conversion into agricultural area, illegal sand mining, construction of cemented pillars for bridge, are just to name a few leading causes of its dwindling status. The present study is a data generated for seasonally for one year and assessment of the degrading parameters were made. Based on the water quality parameters, the wetland turned out moderately alkaline in nature and WQI showed poor water quality at all the study stations, depicting its deteriorating state. Also, aquatic insects that serve as important bioindicators were implemented for assessing the water quality using various biotic indices. Thus, a pioneer attempt has been made to decipher the causes of the continuing deterioration status of this immensely important wetland by analyzing its hydrobiology, which if not paid heed, will result in total territorialization of this intermediate water resource. [ABSTRACT FROM AUTHOR]

As bioindicators, benthic macroinvertebrates are often used to assess stream quality. Based on standard hydrobiological study techniques, the physicochemical and biological health status of the Missolé stream was assessed. Waters of the Missolé stream were found to be slightly acidic (pH: 6.23–6.26) and well-oxygenated (O2: 69.80–76.80%), with low values of temperature (T°: 23.60–24° C), turbidity (49.40–88.40 FTU) and mineralized ions (NH4+: 0–1.19 mg/L; NO2-: 0–1.61 mg/L; NO3-: 0.02–6.80 mg/L). Concerning aquatic invertebrate communities, a total of 489 individuals, grouped in two classes, eight orders and 35 families, all belonging to the phylum Arthropoda, were collected and identified. The class of Insecta was the most diversified, with seven orders and 32 families, while that of Crustacea had only one order and three families. Overall, Insecta accounted for 52.35% of the total abundance, and Decapod Crustacea was 47.65%. The three predominant families were Palaemonidae, Dytiscidae and Atyidae. Shannon and Weaver (H') and Piélou's evenness (J) indices were high at all stations and showed a slight decrease from upstream to downstream. In the same vein, the Hilsenhoff Biotic Index (HBI) classified the water quality of the Missolé stream as medium. Overall, this suburban aquatic ecosystem offers moderately favorable living conditions for aquatic biota. [ABSTRACT FROM AUTHOR]

To address ongoing threats from human pressures and climate changes, water managers and users require a visual tool that provides accurate information about the health of waterbodies for decision making. However, there is a lack of less sophisticated methods, such as biotic scoring, to assess the health of rivers in West Africa. To bridge this gap, we have developed a macroinvertebrate-based scoring system for monitoring the health of rivers in the Sahelian regions. We adopted a multi-habitat sampling approach to collect macroinvertebrates using hand nets, and these specimens were identified mostly to family taxonomic level using keys. We recorded more than 75 taxa of macroinvertebrates, each assigned relative sensitivity scores to human disturbances ranging from 1 (very tolerant) to 10 (highly sensitive). The Burkina Biotic Score System (BBIOSS) and the Average Score Per Taxa (ASPT) demonstrated a strong and significant correlation with environmental variables, including anthropogenic pressures types (r = 0.6; p < 0.01) making it a robust tool for monitoring rivers. Here, our findings revealed that all taxa scored are expected to be those reported in Western African freshwater. This study has produced an effective tool that can be used or adapted to monitor other riverine ecosystems in West Africa, potentially contributing to the preservation of water and biological resources. [ABSTRACT FROM AUTHOR]

Diatoms are commonly used in environmental assessments to detect pollution and eutrophication. The specific pollution sensitivity index (SPI) is one of the most frequently used indices, which assigns scores to diatom taxa based on their sensitivity to pollution. The study analyzed diatom communities in the Duero River basin in Spain to examine the relationship between SPI scores and various limnological variables. A GLM model showed that phosphates, nitrites, and water temperature were the main factors explaining SPI variability. The study also reviews previous results using SPI for water quality monitoring in different world regions, highlighting the role of nutrients in general as major drivers of SPI values worldwide. Overall, the findings reinforce the reliability of SPI as a metric for biological monitoring in various watercourses. [ABSTRACT FROM AUTHOR]

Water quality and self-purification capacity of the Disam River (Iran) was studied using macroinvertebrate-based indices and Qual2kw mathematical modeling tools. We evaluated the water quality and self-purification status of the Disam River through biotic indices of macroinvertebrates and mathematical modeling (Qual2kw). A total of 10,370 macroinvertebrate specimens were collected monthly using a Surber sampler (30 × 30 cm) at five sampling sites from 2019 through 2020. The Hilsenhoff Family Biotic Index (HFBI) and Average Score Per Taxon (ASPT) indexes categorized the sampling sites 2 and 3 in "Moderate " and "Very poor " water quality classes. The Ephemeroptera, Plecoptera, Trichoptera (EPT) index categorized the river at "Good", and the Biological Monitoring Working Party (BMWP) at "acceptable " classes of water quality. We used Canonical correspondence analysis (CCA) to explain the relationships between biotic indices and physicochemical parameters. The EPT index showed a positive correlation (axis1 = 1/43, axis2 = 0.065) with most physicochemical factors of the Qual2kw. Analyses of the Qual2kw output and macroinvertebrate occurrence showed that the family Chironomidae was dominant (S2 = 37.66% and S3 = 47.33%) in all seasons except summer. Family Baetidae was dominant in S2 (79%) and S3 (78%) with a weak positive correlation with increasing stream temperature (r = 0.21) and slightly negative correlation with increasing stream velocity (r = -0.053). Analyses of BOD and DO fluctuations confirmed the ongoing flushing of pollutants along the Disam River. Our findings highlight the importance of simultaneous study of biotic indices and mathematical modeling in assessment of "ecological integrity" and flexibility of aquatic ecosystems subjected to anthropogenic impacts. [ABSTRACT FROM AUTHOR]

Nature-based solutions, such as shellfish reefs, can support natural coastal defence and be a potential solution for climate-resilient shorelines in the future. In the Belgian Part of the North Sea, the "Coastbusters" projects aim to develop nature-based coastal protection by favouring subtidal mussel bed establishment on the seafloor through typical longline aquaculture techniques. Mussel beds are dependent on environmental conditions, and both influence the physical and biogeochemical features in a soft-sediment environment. Therefore, a comprehensive ecological monitoring program is essential to assess the success of future mussel bed development and its influence on the surrounding ecosystem. For establishing a monitoring baseline of the two experimental areas, a combination of conventional benthic assessment methods (grab sampling and granulometry) and non-invasive techniques (sediment profile imaging and transect diving video surveys) were utilised. Although mussel reefs did not yet develop by the time of this study, clear differences in ecological and sedimentological characteristics were found between two experimental areas (sheltered and exposed), subjected to slightly different hydrodynamic conditions. The one sheltered by coastal sandbanks was dominated by fine-muddy sand, higher species richness, biomass, and higher biological activity (burrows, fauna, and biological beds) as observed by all methods in one or another way. Moreover, functional diversity indices revealed a higher partitioning of the total available resources, suggesting more complex ecological processes in the sheltered area. Conversely, the area more exposed to the open sea was dominated by more sandy sediments, and fewer organisms were found. The combination of those different monitoring tools provides an integrated, complementary view, from different perspectives, on the biological, physical and functional characteristics of the study areas. [ABSTRACT FROM AUTHOR]

The macroinvertebrate community, physical–chemical water variables and hydromorphological indices were studied in the Turón River (Málaga, Southern Spain). Our study aims to improve the knowledge of the most influential environmental factors at different spatial and temporal scales in Mediterranean rivers, in order to establish better management of Mediterranean river ecosystems. To this end, in this work, seasonal sampling was carried out for one year to evaluate the effect of the characteristics of the drainage basin (i.e., geology, topography, land use) on the macroinvertebrate community. To this end, the environmental variables of the catchment basins were evaluated at three different scales: (i) watershed level, (ii) valley segment level and (iii) local level. The results showed that 13 environmental variables, 3 at the watershed scale, 5 at the valley segment scale and 5 at the local scale, influenced the macroinvertebrate community. Land use is the main explanatory variable at the watershed scale, while stream channel curvature is the most common variable at the valley segment scale, and the habitat assessment index is the variable with the strongest influence at the local scale. The influence of different spatial scales presented a seasonal variation. During spring, autumn and winter, the watershed scale exhibited the highest resolution (adjusted R2 = 0.20–0.29), while in summer, the local scale became the most significant in explaining the presence of macroinvertebrate taxa (adjusted R2 = 0.17). The obtained results emphasize the significance of temporal and spatial scales in Mediterranean rivers for adequate river ecosystem management. [ABSTRACT FROM AUTHOR]

This article presents the results of a study of zoobenthos of the Ural River in an area from the town of Verkhneuralsk to the city of Orenburg (about 1000 km) with sampling upstream and downstream of sources of anthropogenic impact: large cities, metallurgical plants, treatment facilities (TFs), and reservoirs. The degree of pollution was estimated using the Shannon and EPT indices, as well as the Woodiwiss index, an indicator that partially takes into account the first two indices. It is shown that the selected parameters decrease downstream of the sources of anthropogenic impact, thereby reflecting a decrease in the species diversity of benthic biocenoses and a decrease in the number of indicator species sensitive to pollution. Small streams are particularly affected; pools are subject to greater transformations than riffles. An integrated indicator of water quality based on biological parameters is proposed. It was used to rank all studied areas by the degree of pollution. It is shown that ten of the 23 studied river areas are assigned to the 1st class of water quality (conventionally clean areas), seven areas to the 2nd class (weakly polluted areas), three areas to the 4th class (dirty areas), and three areas to the 5th class (extremely dirty areas). This indicates that, despite multiple sources of pollution, the Ural River has a high self-purification capacity and most of the studied areas are quite clean and favorable for the habitation of benthic invertebrates. [ABSTRACT FROM AUTHOR]

Continuous wetland restoration initiatives in China are increasing, due to the global degradation of wetland ecosystems. However, monitoring of the restoration situation remains incomplete. In this study, we investigated the effects of wetland restoration on the macroinvertebrate taxonomic structure and feeding functional groups (FFGs) in the Naolihe National Nature Reserve (NNNR). Macroinvertebrate taxonomic diversity can be used to monitor wetlands, and we hypothesized that FFGs serve the same function. We calculated the diversity index, performed a non-metric multidimensional analysis based on macroinvertebrate taxonomics and FFGs, and subsequently, performed a t-test on the results. The results showed that macroinvertebrate diversity and FFGs analyses were in general agreement with taxonomic diversity, indicating that the macroinvertebrate community in the wetland with five years of fallow land was resembled that of the natural wetland. In contrast, the macroinvertebrate community in the wetland with two years of fallow differed significantly from that in the natural wetland. Additionally, the results of the ecosystem attributes based on biomass and FFGs showed that restored wetlands exhibited lower habitat stability than natural wetlands. Nutrients (NH4+-N, NO3−-N, and total phosphorus) explained the changes in macroinvertebrate FFGs in the restored wetlands to a greater extent than in the natural wetlands. The results of this study highlight the importance of macroinvertebrate FFGs in wetland monitoring, which supports the use of macroinvertebrate FFGs in the NNNR to monitor wetland restoration.

This study shows the results of a water quality assessment for the Basin of the Cane River, which belongs to Iguaque Flora and Fauna Sanctuary National Natural Park, a naturally protected area formed by the Andean Forest and paramo ecosystems in Colombia. The water quality of this river is impacted by agricultural runoff and domestic wastewater from human activities in the buffer area. This was assessed by using chemical, physical, and biological indexes. The IDEAM, NSF and water quality indexes were based on the European standards of measurement. Further to this, BMPW/Col and ETP biological indexes were analyzed and, amongst these, IDEAM WQI (Water quality index) and ETP showed a good correlation. A similar trend was found between the IDEAM water quality index and BMWP/Col index, showing their potential as a good tool for water catchment, diagnosis, assessment, and management in Andean paramo basins. In total, 537 specimens of macroinvertebrates were collected, identifying 8 taxonomic orders, 16 families and 18 genera. Predominant orders were Trichoptera, Ephemeroptera, and Diptera. Baetidae and Planariidae taxas were found in the three water quality levels, showing a decrease in number with a decrease in water quality. Thus, both species have shown sensibility to water quality parameters and also to riverine habitat quality, being then interesting species to determine water quality, deserving more detailed studies for similar cases in high Andean forests and paramo basins.

Qualitative assessment by macro-invertebrates is known as a suitable method to determine the health of the river. In this study, the diversity and abundance of Baliqlu River macro-invertebrates were evaluated from June 2019 to May 2021. SamplingsSamples were taken by Surber sampler during four seasons and physico-chemical parameters such as TEM, DO, pH, BOD, and some heavy metals (Cd and Pb) were measured. Diversity indices (Shannon-Wiener), and biotic indices (EPT, HFBI, and BMWP) were calculated in four stations. A total of 8328 macro-invertebrates from the Diptera, Ephemeroptera, and Isopoda were identified. The highest frequency percentage of the dominant groups was related to the Caenidaed, Chironomidae, and Simuliidae. The results of heavy metal accumulation in two classes showed more cadmium and lead accumulation in the Clitellata class (suborder Hirudinea) than the Insecta class (Caenidae family). The results of conventional comparative analysis (CCA) demonstrate that the distribution of most macro-invertebrate families is influenced by the DO parameter. According to the HFBI, the water quality decreased from upstream to downstream in all seasons, and the level of pollution was higher in station 5 compared to other stations, due to human activities, cattle crossing, and sewage output of fish farms.

With the growing global focus on marine environmental conservation and management, it is imperative to evaluate the ecological quality of marine ecosystems accurately. In this study, we employed seven biotic indices, namely the AZTI marine biotic index (AMBI), BENTIX, benthic opportunistic polychaetes amphipods index (BOPA), benthic pollution index (BPI), multivariate AZTI marine biotic index (M-AMBI), abundance biomass comparison (W-value), and Shannon diversity index (H'), to assess the benthic ecological quality in the intertidal zone of Cheonsu Bay, South Korea. Except for the H' and W-value, the indices (AMBI, BENTIX, BOPA, BPI, and M-AMBI) suggest that the ecological quality at most stations in the intertidal zone of Cheonsu Bay was acceptable. Furthermore, the influx of a large amount of eutrophic freshwater has impacted the intertidal zone of Cheonsu Bay, but the applicability of the seven biotic indices requires further investigation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Qualitative assessment by macro-invertebrates is known as a suitable method to determine the health of the river. In this study, the diversity and abundance of Baliqlu River macro-invertebrates were evaluated from June 2019 to May 2021. SamplingsSamples were taken by Surber sampler during four seasons and physico-chemical parameters such as TEM, DO, pH, BOD, and some heavy metals (Cd and Pb) were measured. Diversity indices (Shannon-Wiener), and biotic indices (EPT, HFBI, and BMWP) were calculated in four stations. A total of 8328 macro-invertebrates from the Diptera, Ephemeroptera, and Isopoda were identified. The highest frequency percentage of the dominant groups was related to the Caenidaed, Chironomidae, and Simuliidae. The results of heavy metal accumulation in two classes showed more cadmium and lead accumulation in the Clitellata class (suborder Hirudinea) than the Insecta class (Caenidae family). The results of conventional comparative analysis (CCA) demonstrate that the distribution of most macro-invertebrate families is influenced by the DO parameter. According to the HFBI, the water quality decreased from upstream to downstream in all seasons, and the level of pollution was higher in station 5 compared to other stations, due to human activities, cattle crossing, and sewage output of fish farms. [ABSTRACT FROM AUTHOR]

Habitat degradation is one of the major reasons for freshwater species decline. Hydrogeomorphological processes (such as sediment transport, bank erosion, and flooding) operate at the catchment scale and determine habitat features in river reaches. However, habitat quality indices and restoration for freshwater fish species are often implemented at small spatial scales of a few hundred metres. The Morphological Quality Index (MQI) considers fluvial processes at larger scales as well as channel forms, human impacts, and historical changes, but few studies have assessed its relevance for ecosystem health. We investigated relationships between the MQI, habitat quality (using the Qualitative Habitat Evaluation Index, QHEI), land cover, and fish metrics (number of fish species, index of biotic integrity (IBI), and trout biomass) in 26 salmonid streams in Aotearoa New Zealand and Southern Ontario, Canada. We found a significant correlation between the MQI and QHEI, and both metrics were correlated with urban and native forest proportion in the catchment. However, we found no relation between the MQI and the proportion of agricultural land in the catchment, while the QHEI was correlated with agricultural land in the riparian zone, highlighting the importance of vegetated riparian buffers in providing fish habitat. Establishing a strong correlation with fish metrics remains challenging. Nevertheless, a modified MQI targeting ecological health could be used as an effective management tool for aquatic conservation. [ABSTRACT FROM AUTHOR]

Nayband Bay has been greatly influenced by a variety of human disturbances over the last three decades. The present study was undertaken to assess the ecological quality status of macrobenthic communities in Nayband Bay sediments using four benthic indices namely AMBI, M-AMBI, BENTIX, and H´. The sediment samples were taken for macrobenthos extractions and determination of grain size analysis, Total Organic Matter (TOM), and Total Organic Carbon (TOC) using a Van Veen grab. A total of 47 macrobenthos taxa (genus and species) were identified among 34825 individuals in the sampling area. Polychaeta, Malacostraca, Bivalve, Gastropoda and Echiura were the most abundance taxon with 23 (48.9%), 11 (23.4%), 6 (12.7%), 5 (10.6%), and 2 (4.2%) species. The results showed that the macrobenthic communities were characterized by sensitive (EGI) or indifferent (EGII) species of AMBI ecological groups. The opportunistic species (EGIV and V) namely Capitella capitata, Cirratulus ciratus, and Scolelepis sp. were dominated at stations with high TOC. These stations were close to the beach, where the organic matter discharges and wastewater have been released from industrial outfalls. In general, the EcoQs were “good” or “acceptable”, although four indices showed some differences in the EcoQs classifications for a given site. The results of the present study indicate that the complementary use of different indices, especially sensitivity/tolerance-based indices, is recommended for the ecological status assessment of the Iranian coastal waters of the Persian Gulf. [ABSTRACT FROM AUTHOR]

Assemblages of infralittoral periphytic algae are understudied due partially to the historical emphasis on phytoplankton and other water-column characteristics to evaluate the integrity of lentic systems. We tested the null hypothesis that characteristics of epilithic algal assemblages at infralittoral sites in reservoirs of Middle and East Tennessee do not infer trophic state. One infralittoral site in five mesotrophic and five eutrophic reservoirs in Middle and East Tennessee was sampled to determine the relative abundance of the most common epilithic diatoms and soft algae, concentrations of epilithic chlorophyll (chl) a, and water concentrations of chl a, total phosphorus (TP), and total nitrogen (TN). The concentration of epilithic chl a correlates significantly to the concentration of TP but not to TN as determined by the probability values for Pearson's correlation coefficients. The water concentration of chl a does not correlate significantly to concentrations of TP, TN, or epilithic chl a. Trophic-state indicator values for 162 epilithic diatom taxa and 102 epilithic soft-algal taxa are calculated as the abundance-weighted average of the concentration of epilithic chl a normalized between 0 and 100. The trophic-state indicator values indicate the relationship of the abundance of algal taxa to trophic state and contribute to our limited knowledge of the effects of eutrophication on infralittoral algal taxa. Trophic-state indices are calculated as the mean abundance-weighted average of trophic-state indicator values for algal taxa of an assemblage. The index values infer the trophic state of the sites and are the first to use epilithic concentrations of chl a as opposed to water-column characteristics to indicate trophic-state optima for periphytic algae of lentic systems. The indices are easy to calculate and provide novel tools to help evaluate and monitor the trophic state of infralittoral sites in reservoirs of Middle and East Tennessee. [ABSTRACT FROM AUTHOR]

For the sustainable use of lake ecosystem services—water resources, aquatic habitats for biodiversity conservation, and aesthetic values as waterfront space—ecosystem health assessments using biota are implemented as important national environmental monitoring projects. Zooplankton play a key role as an important linkage in the material circulation as secondary producers in lake ecosystems. At the same time, they influence the composition and biomass of other communities through biological interactions. In this review, we summarize useful zooplankton indices for ecosystem health assessment and suggest considerations for their use. Suggestions are provided for the practical application of indirectly measured zooplankton biomass, as well as the potential and limitations of eDNA application, which has recently been actively utilized in biological monitoring. [ABSTRACT FROM AUTHOR]

Today, the application of ecological indicators based on organisms has replaced traditional saprobic approaches for assessment of the quality of rivers impaired due to organic pollution and some other environmental disturbances. This study aimed to weigh the quality of the Ojarud River in Ardabil, Iran, applying biological and physiological indices of macro‐invertebrates. A total of 12,524 samplings were fulfilled at four stations (S1, S2, S3, S4) from the headstream to downstream by a Surber sampler (30 × 30 cm2) from June/2020 to April/2021. All year round, the highest frequent families were Chironomidae (2658), Simuliidae (1025) from Diptera and Caenidae (1855), and Baetidae (724) from Ephemeroptera. The diversity pattern was analyzed by PAST software, and Primer 7 (BIO‐ENV analysis) was utilized to understand what factor has the most impact on the distribution of macro‐invertebrates. The least similarity of S4 to other stations was recognized by Cluster analysis. As per the ANOSIM (analysis of similarities), a statistically significant difference in the macroinvertebrates' frequency was established between S3 and other stations (p =.0001, r =.63). Moreover, the relationship between heavy metals and macro‐invertebrate showed that the three families of Simuliidae, Gomphidae, and Caenidae had a positive correlation with the concentrations of heavy metals in the sediment. As per the Ephemeroptera, Plecoptera and Trichoptera index, the water quality was placed in the "excellent" class, but the Biological Monitoring Working Party and Hilsenhoff Family Biotic Index indices scored the water quality "good" class at S1 and the "poor" class at S3. Based on the results of this study, the use of physicochemical and hydro‐morphological indicators can support the biological indicators but cannot replace them. In addition, careful evaluation of biological indicators is required to develop conservation strategies. [ABSTRACT FROM AUTHOR]

The relationship between spatial patterns of macrobenthic community characteristics and environmental conditions (dissolved oxygen, temperature, salinity, organic matter content and sediment particle size) was studied at 12 stations in Gorgan Bay (South Caspian Sea, Iran), seasonally in 2017. A total of 8803 individuals belonging to 11 families and 11 species were identified. Three species of polychaeta including Streblospio gynobranchiata, Tubificidae and Hediste diversicolor were the most dominant group in terms of abundance, making up 79.3% of all specimens. The highest density (4733 ind m-2) was observed at St. 1 while the lowest (1166 ind m-2) at St. 9. Biotic indices (i.e. AMBI, BOPA and BENTIX) were used to determine the quality of the bay. Gorgan bay is divided into two distinct zones (eastern and western regions) based on MDS analysis and ecological status. Generally, eastern part of the bay revealed the lowest abundance and biodiversity of macrobenthos. Our results suggest the effect of sediment particle size and TOM as significant parameters on distribution of macrobenthic community in Gorgan bay, South Caspian Sea. [ABSTRACT FROM AUTHOR]

The aquatic ecosystem is compromised by many contaminants that may reduce ecosystem functions and severely affect human health. This study aimed at determining suitable phytoplankton bioindicators of water quality for biomonitoring of freshwater streams in the monomodal agroecological zone of Cameroon. Water physicochemical and hydrological parameters, together with phytoplankton abundance and diversity, were measured from June 2016 to May 2017 along the Benoe Stream. Principal component analysis and redundancy analysis were used to determine phytoplankton spatial and temporal distribution and identify indicator species. The Shannon–Wiener diversity and Pielou's evenness indices indicated a clean to mildly polluted stream with a diverse phytoplankton community consisting of 84 genera belonging to 51 families that was dominated by the Bacillariophyta (64%), followed by Chlorophyta (13%) and Cyanophyta (10%). The total dissolved solids, electrical conductivity, stream water velocity, and discharge were the most important stream characteristics affecting the abundance of the dominant phytoplankton genera. Seasonal variations in the stream characteristics as well as spatial community distribution along an urban—small-scale farming – large-scale farming gradient were unveiled and their influence on the phytoplankton relative abundances. Increased abundance of Synedra ulna was indicative of low TDS and EC, which was the contrary for Gyrosigma baltium dominance. High Pleurosira laevis abundance was associated with the urban zone while high Diatoma sp. and Oscillatoria sp. abundances were related to the large-scale farming zone of the stream. These phytoplankton species have good potential for use as bioindicators for stream water quality monitoring in the monomodal agroecological zone. [ABSTRACT FROM AUTHOR]

Resumption of shipping in the Bystryi branch in the Ukrainian part of the Danube Delta, one of the largest aquatic-wetland areas of Europe and the world, has made it necessary to control the anthropogenic impact on the neighboring water areas of the Danube Biosphere Reserve. The objective of the study was comparing the compositions and structure of phytoplankton, microphytobenthos, macrophytes, benthic invertebrates and ichthyofauna of the mouth area of the Bystryi branch with such communities of the mouths of the branches Vostochnyi, Tsyhanka and Starostambulskyi, which are situated in the protected zone and characterized by limited anthropogenic activity. We also determined the correspondence of the descriptors of biotic groups to the categories of the ecological status according to the Water Framework Directive of the EU. The studies were performed in the autumn and summer periods in 2020–2021. We recorded 367 species of animals and plants, the richest biodiversity was seen for the biota of the Bystryi branch – 250 species, and 180–231 species of hydrobionts were found in the undisturbed mouths. We determined 25.3% of shared species for the water areas, and therefore high values of similarity of the species compositions according to Bray-Curtis (47.5% to 81.5%). We determined no significant differences between the groups of the mouths of the examined branches according to most indicators of taxonomic and ecological structure. As the descriptors of ecological status, we chose assemblage indices of phytoplankton and microphytobenthos, which are based on ratios of biomass of functional groups of algae, and also the Macrophyte Biological Index for Rivers, saprobic index of Zelinka & Marvan and Biological Monitoring Working Party Index of Benthic Invertebrates and Representation of Species of Ichthyfauna according to vulnerability to actions of environmental factors. We determined that the range of descriptors of phytoplankton and microphytobenthos corresponded to the “high” ecological status category, such of macrophytes and benthic invertebrates to “good”, and such of ichthyofauna varied “high” to “good”. In general, all the mouth areas were characterized by “good” ecological status. Similarities of the species composition and the structure of biotic communities of the mouths of the studied branches of the delta indicate the absence of negative impact of the deepwater shipping on adjacent ecosystems, which may be related to the peculiarities of reactions of groups in the water areas with natural stress, as well as local impact of the hydrotechnical construction.

Abstract Today, the application of ecological indicators based on organisms has replaced traditional saprobic approaches for assessment of the quality of rivers impaired due to organic pollution and some other environmental disturbances. This study aimed to weigh the quality of the Ojarud River in Ardabil, Iran, applying biological and physiological indices of macro‐invertebrates. A total of 12,524 samplings were fulfilled at four stations (S1, S2, S3, S4) from the headstream to downstream by a Surber sampler (30 × 30 cm2) from June/2020 to April/2021. All year round, the highest frequent families were Chironomidae (2658), Simuliidae (1025) from Diptera and Caenidae (1855), and Baetidae (724) from Ephemeroptera. The diversity pattern was analyzed by PAST software, and Primer 7 (BIO‐ENV analysis) was utilized to understand what factor has the most impact on the distribution of macro‐invertebrates. The least similarity of S4 to other stations was recognized by Cluster analysis. As per the ANOSIM (analysis of similarities), a statistically significant difference in the macroinvertebrates' frequency was established between S3 and other stations (p = .0001, r = .63). Moreover, the relationship between heavy metals and macro‐invertebrate showed that the three families of Simuliidae, Gomphidae, and Caenidae had a positive correlation with the concentrations of heavy metals in the sediment. As per the Ephemeroptera, Plecoptera and Trichoptera index, the water quality was placed in the “excellent” class, but the Biological Monitoring Working Party and Hilsenhoff Family Biotic Index indices scored the water quality “good” class at S1 and the “poor” class at S3. Based on the results of this study, the use of physicochemical and hydro‐morphological indicators can support the biological indicators but cannot replace them. In addition, careful evaluation of biological indicators is required to develop conservation strategies.

AbstractAssemblages of infralittoral periphytic algae are understudied due partially to the historical emphasis on phytoplankton and other water-column characteristics to evaluate the integrity of lentic systems. We tested the null hypothesis that characteristics of epilithic algal assemblages at infralittoral sites in reservoirs of Middle and East Tennessee do not infer trophic state. One infralittoral site in five mesotrophic and five eutrophic reservoirs in Middle and East Tennessee was sampled to determine the relative abundance of the most common epilithic diatoms and soft algae, concentrations of epilithic chlorophyll (chl) a, and water concentrations of chl a, total phosphorus (TP), and total nitrogen (TN). The concentration of epilithic chl a correlates significantly to the concentration of TP but not to TN as determined by the probability values for Pearson’s correlation coefficients. The water concentration of chl a does not correlate significantly to concentrations of TP, TN, or epilithic chl a. Trophic-state indicator values for 162 epilithic diatom taxa and 102 epilithic soft-algal taxa are calculated as the abundance-weighted average of the concentration of epilithic chl a normalized between 0 and 100. The trophic-state indicator values indicate the relationship of the abundance of algal taxa to trophic state and contribute to our limited knowledge of the effects of eutrophication on infralittoral algal taxa. Trophic-state indices are calculated as the mean abundance-weighted average of trophic-state indicator values for algal taxa of an assemblage. The index values infer the trophic state of the sites and are the first to use epilithic concentrations of chl a as opposed to water-column characteristics to indicate trophic-state optima for periphytic algae of lentic systems. The indices are easy to calculate and provide novel tools to help evaluate and monitor the trophic state of infralittoral sites in reservoirs of Middle and East Tennessee.

With the growing global focus on marine environmental conservation and management, it is imperative to evaluate the ecological quality of marine ecosystems accurately. In this study, we employed seven biotic indices, namely the AZTI marine biotic index (AMBI), BENTIX, benthic opportunistic polychaetes amphipods index (BOPA), benthic pollution index (BPI), multivariate AZTI marine biotic index (M-AMBI), abundance biomass comparison (W-value), and Shannon diversity index (H’), to assess the benthic ecological quality in the intertidal zone of Cheonsu Bay, South Korea. Except for the H’ and W-value, the indices (AMBI, BENTIX, BOPA, BPI, and M-AMBI) suggest that the ecological quality at most stations in the intertidal zone of Cheonsu Bay was acceptable. Furthermore, the influx of a large amount of eutrophic freshwater has impacted the intertidal zone of Cheonsu Bay, but the applicability of the seven biotic indices requires further investigation.

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.

In the present study, we tested the effectiveness of biological trait analysis (BTA) as an ecological indicator in support of the assessment of the Ecological Quality Status (EQS) of a Mediterranean transitional system by commonly used macrobenthic assemblage diversity (e.g. H’ and Margalef) and biotic (BENTIX, M−AMBI and M−bAMBI) indices. Ten biological traits describing morphological, behavioral and life history characteristics were considered for the analysis of the functional structure of macrobenthos. As a test study, a historical dataset obtained from the Cabras lagoon (Sardinia, Italy) comprising a riverine site, the lagoonal main body, a confined pond, a seaward creek and a marine channel connected to the Gulf of Oristano was analyzed. Our results showed clear spatial changes in macrobenthic density, number of species and diversity indices along the riverine-lagoon-sea gradient, which were well reflected in the EQS values based on M−AMBI and to a lesser extent on M−bAMBI. The abundance-based functional diversity was significantly related to the structure and taxonomic diversity of the benthic community. Similarly, the Community-level Weighted Mean test computed with abundance data, rather than with biomass data, supported major evidence for differences in the ecological conditions of the different study sites. In particular, all riverine, lagoonal and confined stations had poor or bad EQS, indicating unstable and warning conditions in this Mediterranean transitional water body. Overall, the BTA approach appeared to be a very promising method in reporting the expected environmental and biotic variability in the Cabras lagoon system and in supporting the EQS assessment by M−AMBI. We conclude that an in-depth knowledge of the benthic communities in terms of both taxonomic and functional aspects is an indispensable basic tool for understanding the variability of the brackish-water systems and for properly assessing their environmental quality.

Developing multi-metric indices (MMIs) as a tool for inland water ecosystem assessment has attracted the attention of the global scientific community. The number of studies, which developed macroinvertebrate-based multi-metric indices for wetlands, however, was very limited. Thus, more work is needed to refine and implement it depending on the ecological contexts of wetlands. On top of this, we developed multi-metric indices based on macroinvertebrate assemblages that could be used for the ecological health assessment of wetlands that are impacted by agricultural activities in North-western Ethiopia. About 20 sampling sites were established in four wetlands along the disturbance gradient to take water and macroinvertebrates samples. The reference sites, which were least disturbed by human intervention, were established for the construction of multi-metric indices. Six core metrics were selected for the development of the final multi-metric indices from fifty-six potential metrics of macroinvertebrate assemblages after passing through sensitivity and statistical tests. The findings demonstrated all reference sites had good or high ecological conditions. On the contrary, the ecological statuses of nearly 70% of the impaired sites were found to be in bad to poor conditions. A significant distinction between reference and impaired sites suggested our index ability to identify the gradient variation in the ecological condition of wetlands. A strong negative relationship of the multi-metric indices model with most of the physicochemical variables and all human disturbance factors also suggested the appropriateness of the developed index in informing the ecological status of wetlands. Thus, we believe that our multi-metric indices could be a useful biomonitoring tool for the assessment and monitoring of wetland ecological conditions in predominantly agricultural landscapes in the Upper Blue Nile basin and beyond.

The time required for diatom assemblages to integrate the abiotic variables of the aquatic environment has been subject of discussion for many years, with contrasting opinions as shown by field observations and experiments. Numerous diatom-based water quality indices are being used in the bioassessment of freshwaters; one of the most widely used (Specific Polluosensitivity Index or SPI) is compared in this study with water quality status as measured by the Water Quality Index (WQI) obtained from limnological parameters measured at 37 fluvial stations belonging to the Duero Basin (NW Spain). The correlation existing between both metrics was determined using different time lags between water and diatom sample collection. Results show that the correlation coefficient increases as the time gap decreases, but is maximal when comparing WQI scores measured one month before diatom sampling. We thus confirm the initial hypothesis that diatom indices actually indicate past (1 month ago) and not current water conditions in rivers. The practical consequences of this finding are briefly discussed. [ABSTRACT FROM AUTHOR]

An ecological index of macrobenthic communities is an important tool for assessing the biological quality of habitats and ecosystems. We tested the performance of the inverse function of the Shannon–Wiener evenness proportion (ISEP) with data from the entire west coast of Korea, seasonally sampled from 2006 to 2008. Two validations were performed: (1) examination of the relationship between ISEP and environmental factors and (2) correspondence between the ISEP and the Pearson–Rosenberg (P-R) model for the species-abundance-biomass (SAB) patterns and taxonomical variations. The ISEP was significantly correlated with suspended solids but independent of other natural habitat conditions due to their low to moderate contamination levels. From this, ISEP performed as expected in transitional zones of low salinity and applications across habitats of various sediments. The SAB patterns and taxonomic variations along the ISEP grades showed marked similarities to the P-R model. The only departure was biomass, which increased after the normal status. The increase was interpreted as reflecting a healthier and more mature status. Taxonomic variation patterns and the taxa composition that characterized either poor or healthy status corresponded well with the P-R model. The conformity to the P-R model indicates the capability and potential applicability of the ISEP to other coastal systems. [ABSTRACT FROM AUTHOR]

A long-term assessment of the benthic habitat quality of intertidal flats in Liaohe Estuary was conducted by three integrating ecological indices, AZTI's Marine Biotic Index (AMBI), Multivariate-AMBI (M-AMBI), and Shannon–Wiener diversity index (H′) based on macrobenthos data from 2013 to 2020. The results showed that the macrobenthic communities were characterized by indifferent and sensitive species of AMBI ecological groups. The annual ranges of H′, AMBI, and M-AMBI were 0.77–1.56, 1.44–3.73 and 0.36–0.54, respectively. Noticeable differences were found among assessment obtained by these biotic indices. Approximately 100%, 24%, and 78% sampling sites had "moderate", "poor", and "bad" statuses as assessed by H′, AMBI, and M-AMBI, respectively. Compared with H′ and AMBI, M-AMBI may be more applicable to evaluate the benthic habitat quality of intertidal flats in Liaohe Estuary. Results suggest that the benthic habitat quality in the middle parts of intertidal flats still had an unacceptable status and has not improved radically to date after large-scale "mariculture ponds restored to intertidal flats". [ABSTRACT FROM AUTHOR]

The relatively rare freshwater ecosystems in the arid southwestern United States serve as biodiversity hotspots, yet they remain among the most threatened systems in the world due to human impacts and climate change. Globally, arid region wetlands remain understudied with respect to their ecology, making assessments of quality or restoration efforts challenging. To address these needs, this project aims to better understand the factors that drive water quality and macroinvertebrate community composition of wetlands of the US desert Southwest. Water quality and macroinvertebrate data were collected over three years from 14 different wetland and riparian sites spanning across West Texas, New Mexico and Arizona. Principal Component Analysis (PCA) indicated that salinity related variables such as chloride, sulfate and conductivity were the greatest drivers of environmental variance (32%) among sampled desert wetlands. Nutrients such as nitrate and phosphate described a second axis, with 22% of variation in environmental data explained, where we found a clear distinction between wastewater and non-wastewater wetlands. Nutrients were shown to have the greatest impact on macroinvertebrate communities with wetlands receiving wastewater showing more uneven distribution of functional feeding groups and lower Simpson Index scores. These sites were dominated by filter feeders and had lower relative abundances of predator and collector-gatherer taxa. There was also a significant decrease in metrics related to diversity and environmental sensitivity such as % Ephemeroptera-Odonata-Trichoptera (EOT) within high nutrient sites. Increased salinity levels were also shown to correlate with lower Simpson Index scores indicating that increased salinity resulted in a decline in macroinvertebrate diversity and evenness. Overall, the nutrients within effluent water have shown to significantly alter community composition especially in desert wetlands where macroinvertebrates may be more adapted to high salinity. Though macroinvertebrate communities in wastewater sites may not fully resemble those of natural wetlands over time, creation of these sites can still benefit landscape level diversity. [ABSTRACT FROM AUTHOR]

Harbours are one of the most disturbed coastal ecosystems due to intensive anthropogenic pressures. This study aimed for the first time to compare anthropogenic impacts in three harbours from the central coast of Tunisia (Mediterranean Sea) employing analysis of heavy metal contamination and ecological quality status (EcoQS). Sampling was carried out in spring 2019 in the fishing harbour of Teboulba, the marina of Monastir, and the commercial harbour of Sousse. The high levels of concentration in heavy metals and organic matter were closely related to the fine-grained fraction of the sediment in the fishing and commercial harbours. A total of 94 macrobenthic species, including five nonindigenous species, were identified belonging to six zoological groups. Multivariate analyses highlighted a strong influence of the harbour activity on the diversity of macrozoobenthic communities. Three benthic assemblages were identified according to their environmental characteristics such as sediment type, organic matter content, and heavy metal contamination. Benthic and biotic indices (H′, J′, AMBI, and BO2A) showed that the EcoQS varied from poor (commercial harbour) to good (marina), and was significantly influenced by harbour activity, organic matter, and heavy metal contamination of the sediment. The present work could be considered as providing important baseline data for the implementation of national environmental policies and management plans in the future. [ABSTRACT FROM AUTHOR]

Bioturbation promoted by benthic macrofauna impacts the biogeochemical processes in the sediment and water column, being an important process in estuaries, which are depositional ecosystems of high ecological importance. Functional diversity provides clear connections between biota and environmental variables, enabling researchers to comprehend the structure and functioning of ecosystems. The functional approach is still an emerging field of studies for estuaries, especially in the context of weather events such as the ENSO – El Niño. We investigated the functional diversity on a sandflat in the Patos Lagoon Estuary, regarding the bioturbation related traits of the benthic macrofauna, during and following the 2002/2003 El Niño event. Our study evidenced that the decrease in salinity caused by the high precipitation during the El Niño was the most influential factor affecting the functional diversity of the macrofauna. This led to assemblages with less potential for bioturbation, decreased stability, and higher prevalence of opportunistic traits. We also found that despite using bioturbation related traits for our analysis, the proportions of sand, silt, and clay in the sediment were not the main drivers of changes in the functional indices or trait composition, presenting less influence than the seasonal variation of temperature. [Display omitted] • Changes in salinity due to the El Niño were the most influential environmental factor affecting the functional diversity. • Although the traits studied related to bioturbation, sediment composition had a minor influence over functional diversity. • Sediment reworking and irrigation, with different taxa as the most influential, both varied similarly due to the ENSO. [ABSTRACT FROM AUTHOR]

The ecological integrity of the Hassar Stream (suburban of Casablanca city, Morocco) is monitored using aquatic indicators (macroinvertebrates). In this study, monitoring water physicochemical quality reveals a high level of organic pollution and nutrients in this stream, mainly due to allochthonous inputs from Mediouna treated wastewater and greywater and solid waste from riparian settlements. In parallel, a total of 85 macrobenthic taxa belonging to three major faunistic groups (annelids, molluscs, and arthropods) were identified in this hydrosystem. The species richness and faunistic diversity increase progressively from upstream to downstream according to the organic and nutrients loads, and the mineralisation of waters. The assessment of the biological quality of the water using index methods (Belgian Biotic Index "BBI", Family Biotic Index "FBI", Iberian Biological Monitoring Working Party "IBMWP" and Iberian Average Score Per Taxon "IASPT") indicates average or acceptable quality levels. Compared to its previous bioecological condition, the improvement of the faunal diversity and the biological quality of Hassar Stream water indicates a progressive recovery of the macroinvertebrates community and its resilience despite the chronic disturbance linked to the discharge of treated water from the Mediouna wastewater treatment plant. Finally, this study shows that biotic indices can constitute a complementary approach to the taxonomic richness and faunal diversity metrics to appreciate the resilience degree of a Mediterranean disturbed stream. [ABSTRACT FROM AUTHOR]

Benthic macroinvertebrates can provide an integrated picture of environmental changes. Health of freshwaters can be assessed based on measured changes in the ecological structure of benthic macroinvertebrates. During the study period, 33 taxa were determined in Ilke Stream. As a result of principle component analysis (PCA), mainly nine components (T °C, EC, TDS, BOD5, NH4–N, NO2–N, NO3–N, PO4–P and CI–) account for 92% of the total variance among the water quality parameters. As a result of the UPGMA analysis, the highest similarity value was observed between the 1th and 2nd sampling points. SI, BMWP, ASPT and BBI indices were more proper than FBI index to determine the water quality of Ilke Stream. The results indicate that these indices should be adapted based on the ecological, geomorphological and environmental features of the regions. [ABSTRACT FROM AUTHOR]

Geothermal waters utilization is generally considered an environmentally friendly compared to non-renewable sources. However, the discharge of spent geothermal waters, legally classified as wastewater, poses potential environmental burdens. This study aimed to determine the extent to which treated spent geothermal waters impact the quality of the river into which they are discharged. Analyses were conducted on the effluent prior to its mixing with the receiver, and on the receiving waters both downstream and upstream of the effluent outflow. Additionally, aquatic macroinvertebrates were sampled at the outflow, 100 m downstream, and 150 m upstream. The results revealed no statistically significant differences in most analysed parameters (temperature, pH, chlorine, nitrites, phosphorus, and BOD) between the reference section and the section below the outflow. A total of 4519 aquatic macroinvertebrates were collected during the field survey. Multi-metric multidimensional scaling indicated significant differences in assemblages between the sections just upstream of the outflow and those above and below, which showed no variation in taxonomic composition. The lowest values of diversity and biotic indices occurred in the site where the effluent was discharged closest to the bank (1 m) and in the transect 3 m from the bank. In contrast, the transect furthest from the bank (5 m) exhibited parameters comparable to the reference section. No significant differences were observed for most parameters between the sections 100 m below and 150 m above. The findings suggest that the discharge of treated effluent into the river has a localized impact confined to the immediate vicinity of the outflow and does not extend over a broader gradient. The results highlight that with sufficient wastewater treatment and a hydromorphologically diverse receiving body, the negative impacts of geothermal discharge on river biodiversity are mitigated. This study provides a novel examination of a relatively under-applied approach., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In the Anthropocene, man has imposed his activities above the natural processes of ecosystems. Rivers have undergone major changes associated with urban centers, so monitoring them is important to determine their status and suitability to provide environmental services. Studies applying the community ecology approach, such as energy flow in aquatic macroinvertebrate assemblages, may be appropriate to determine their status and functioning. This study characterized an Andean river that runs across the city of Ayacucho (Peru). Water physicochemical parameters and biotic quality indices were used and compared with the abundance of trophic guild components and functional feeding groups to demonstrate that the latter are at least equally suitable to estimate water quality. The river section studied ranged from 2640 to 2900 m a.s.l. and was monitored in the wet and dry seasons. Six monitoring stations were established according to the extent of the influence of the urban center. Water physicochemical variables and macroinvertebrate abundances were determined. A Surber net was used for multihabitat sampling; macroinvertebrates were identified to genus level (in most cases) and counted to estimate relative abundances. Trophic guilds (detritivore, predator, herbivore) were formed using the genus data from identification according to the information available in Argentina, Colombia, Ecuador, Bolivia, and Peru. Functional feeding groups were set based on the classification of families. The sensitivity of trophic metrics was assessed by relating them to environmental variables and the Andean Biotic Index (ABI), the Biological Monitoring Working Party adapted for Colombia (BMWP/Col.), and the Ephemeroptera, Plecoptera, Trichoptera (EPT) indices. Environmental variables and biotic indices increased significantly in the most impacted stations, where the abundance of most taxa decreased. The components of trophic guilds and functional groups varied, and those feeding on fine particles increased in sites with a higher urban impact. The metrics based on trophic characteristics were highly correlated with the BMWP/Col and ABI indices. Therefore, these indices can be used to estimate river water quality and provide information on its functioning.