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Biological assessment of rivers is critical for evaluating ecosystem health, detecting ecological changes, validating physicochemical monitoring data, assessing the effectiveness of water treatment systems, conserving biodiversity, and guiding water resource management. In this study, the surface water quality of the Karkheh River basin was evaluated using the National Sanitation Foundation Water Quality Index (NSFWQI) and the Iranian Surface Water Quality Index (IRWQIsc) for qualitative analysis. For biological monitoring, the Biological Monitoring Working Party (BMWP) index, along with the Average Score per Taxon (ASPT) and the Hilsenhoff Biotic Index (HFBI), was employed to provide a comprehensive assessment. Water quality was analyzed across 18 sampling stations, revealing significant spatial variation. Upstream areas exhibited relatively good conditions, with NSFWQI and IRWQIsc values of 59 and 68, respectively. In contrast, downstream locations near urban and agricultural areas demonstrated poor water quality, with values of 27 and 33, respectively.Overall, approximately 70% of the river's length has been severely impacted, highlighting the need for targeted planning and management to mitigate pollution. The biological indices corroborated the physicochemical results, revealing severe ecological stress in polluted regions. The close alignment between the NSFWQI and biological indicators emphasizes the importance of a multifaceted approach in assessing aquatic health. Key factors contributing to the river's degradation include excessive water extraction, untreated wastewater discharge, and diminished self-purification capacity, particularly in downstream areas. [ABSTRACT FROM AUTHOR]

Background: Water quality is usually measured using various indicators based on physical, chemical and biological parameters. By using the biological index that is based on the identification of the arthropod families, it is possible to make a logical judgment about the ecosystem condition. The aim of this study was measuring correlation coefficients between qualitative and biological Indices. Methods: Water samples were collected 27 samples in northwest of Iran and aquatic insects’ samples 54 in 2019. The NSFWQI and IRWQISC as the most important indices of physical and chemical quality of water ranged from 54.45– 76.21 and from 41.32 to 77.40, respectively. Results: A total of 2,953 aquatic insects were collected, and biological Index ranged from 6.26 to 3.38. It can be stated that increasing in the concentration of pollutants in the source and end of the river could lead to a sharp decrease in biological index. IRWQISC index, the effluent stations of fish farms can fit into ‘fairly bad quality’ and ‘moderate quality’ categories. Conclusion: The linear regression analysis revealed a significant relationship between the Hilsenhoff biological Index and the physiochemical parameters of pH, DO (Dissolved Oxygen) and total dissolved solids. The activity of fish farms and discharging their effluents into water sources, can change the physical, chemical and biological parameters of receiving waters, therefore it is recommended that the location of these units be reviewed and also the appropriate treatment for such effluents should be considered, so that the health risks caused by them can be effectively reduced. [ABSTRACT FROM AUTHOR]

Most of the world's aquatic ecosystems are experiencing a substantial decline in their ecological services. This research was conducted to investigate the ecological condition of the Tajen estuary using the Nygaard-Palmer index at six stations during both cold and warm seasons. The results led to the identification of 32 genera belonging to 27 orders and 8 classes of phytoplankton. The identified phytoplanktons were classified into five orders: Ochrophyta, Chlorophyta, Cyanophyta, Euglenophyta, and Pyrrophyta. The highest species richness was observed in Bacillariophyceae. Thirteen genera that are tolerant to pollution were identified, and the results indicated that the ecological condition of the Tajen estuary is undesirable, with a status index calculated as very polluted, exceeding 20 in both warm and cold seasons. Field investigations also revealed that the Tajen estuary is affected by various environmental hazards at both local and catchment scales. These hazards have created unfavorable conditions and pressure on this habitat, resulting in a shift towards more pollution-tolerant species within the estuary. Overall, this index can be recommended for the biological and ecological assessment of other estuaries in the southern Caspian Sea basin. To reduce uncertainty, other suitable complementary indices may also be employed. [ABSTRACT FROM AUTHOR]

Soil is a very fragile ecosystem, often subject to many threats. Wildfires can affect edaphic communities depending on the intensity and seasonality of the fire. Different groups of soil fauna tend to respond differently to this type of disturbance, but the lack of data prevents to fully analyze the impact of fire. Soil microarthropods show a particular sensitivity to disturbances of different nature, making them excellent biological indicators. That is why in recent years many biotic indices to assess soil quality, like QBS-ar (Soil Biological Quality based on arthropods), have been developed. The objective of this study was to evaluate whether there might be a significant difference between areas affected or not by fire in the locality of Andonno (Piedmont, Italy) in terms of QBS-ar values, 18 years after this disturbance, and whether the reforestation intervention is having a positive effect on soil quality. Two sampling sites were selected within the sampling area and in each, six soil samples were taken. Microarthropods were extracted with a Beriese-Tüiigren extractor and soil biological quality was calculated using the QBS-ar index. No significant difference in QBS-ar values were found between the fire burned and unburned areas (p=0.37). The number of biological and euedaphic forms in the two sites was similar. It appears that microarthropod communities manage to recover in a short time, indicating that in the study area soil fauna has shown a fast recovery after extreme events like wildfires. [ABSTRACT FROM AUTHOR]

This research summarizes the data on benthic macroinvertebrates collected in the 15 streams during spring (June) and fall (September–October) of 2022. The objectives of this study were (i) to evaluate the quality of surface waters, sediments, and benthic macroinvertebrates; and (ii) to compare the relationship with the environmental variables in water, sediments and benthic macroinvertebrates that inhabit 15 streams. A total of 114 taxa were collected. The assemblages from the 15 sites were dominated by Chironomidae and Tubificidae, especially Chironomidae constituted 45.0% density occurrence. The low grades of Benthic Macroinvertebrate Index (BMI) were calculated in 10 sites with disturbed ("poor" or "very poor"). Low BMI sites mostly showed Tubificidae or Chironomidae dominant characteristics. The biological indices, BMI, % Tubificidae, and % Chironomidae, were significantly correlated with DO and conductivity. DO was also significantly correlated with all the benthic macroinvertebrate factors and diversity except percent Tubificidae. The heavy metal parameters were correlated mostly with species number, BMI, and diversity index. The objectives of this study examine the diversity of benthic macroinvertebrate in the 15 streams and investigate the relative importance of environmental quality for benthic macroinvertebrate distribution. [ABSTRACT FROM AUTHOR]

The spawning stock of sockeye salmon in the Bolshaya River is evaluated for 1929–2022. Long-term tendencies are determined for their most important biological parameters, in particular, a juvenilization of returning spawners with decreasing of their body size, weight, and fecundity. Possible causes of these processes are considered. Biological indices of the sockeye salmon belonged to different races, ecological forms, ecotypes, and genders are compared statistically for different periods of time, with the frequency analysis. Changes in the size and age structure are revealed — range of the size and age variability has decreased. The age structure in the sea adjacent to the Bolshaya River mouth contradicts the hypothesis of a significant portion of sockeye salmon from Lake Kurilskoye in seine by-catch. The sockeye salmon abundance has changed periodically and recently is at the top of the wave. Compared to the 1929–2000 average, the stock has increased 6–7 times by 2020, and more than tenfold in 2022, whereas the average multiplicity of reproduction has increased 9 times (such a high value is obviously due to underestimation of spawning).

Soil is a very fragile ecosystem, often subject to many threats. Wildfires can affect edaphic communities depending on the intensity and seasonality of the fire. Different groups of soil fauna tend to respond differently to this type of disturbance, but the lack of data prevents to fully analyze the impact of fire. Soil microarthropods show a particular sensitivity to disturbances of different nature, making them excellent biological indicators. That is why in recent years many biotic indices to assess soil quality, like QBS-ar (Soil Biological Quality based on arthropods), have been developed. The objective of this study was to evaluate whether there might be a significant difference between areas affected or not by fire in the locality of Andonno (Piedmont, Italy) in terms of QBS-ar values, 18 years after this disturbance, and whether the reforestation intervention is having a positive effect on soil quality. Two sampling sites were selected within the sampling area and in each, six soil samples were taken. Microarthropods were extracted with a Berlese-Tüllgren extractor and soil biological quality was calculated using the QBS-ar index. No significant difference in QBS-ar values were found between the fire burned and unburned areas (p=0.37). The number of biological and euedaphic forms in the two sites was similar. It appears that microarthropod communities manage to recover in a short time, indicating that in the study area soil fauna has shown a fast recovery after extreme events like wildfires.

Soil fauna has a crucial importance for the functioning of ecosystems and their conservation. Soil biota has a role in soil formation and distribution of organic matter, and groups like microarthropods can be used as indicators to assess soil quality and are often employed in monitoring programs. In the present study, the QBS-ar index, an index based on the presence/absence of microarthropod groups, was used to assess the level of soil quality in nine different sampling sites in the “Parco Naturale delle Alpi Marittime” and in the “Parco Naturale del Marguareis” (Cuneo, Piedmont). Forest soils, with different degree of management, and open environments (e.g., grasslands and peatlands) were analyzed comparatively, to investigate whether microarthropod fauna might be influenced by management and habitat type. The results show QBS-ar values are significantly higher in woodland soils compared to grasslands and peatlands (p < 0.05). The latter shows no significant difference between each other, although grasslands show a large range of values (108–214). Forest management does not seem to influence QBS-ar values (183–239), showing stable microarthropod communities both in the managed and unmanaged areas. In addition to this, QBS-ar values do not differ significantly in the different forest coenoses, confirming that woodlands have similar index values (p = 0.7). This study confirms that QBS-ar values in natural areas can vary depending on the environment. It is therefore important to consider clustering habitat types before assessing quality classes for QBS-ar values. Finally, sustainable forest management in the study area does not seem to affect significantly soil microarthropod presence in woodland sites. [ABSTRACT FROM AUTHOR]

Grassland health assessment (GHA) is a bridge of study and management of grassland ecosystem. However, there is no standardized quantitative indicators and long-term monitor methods for GHA at a large scale, which may hinder theoretical study and practical application of GHA. In this study, along with previous concept and practices (i.e., CVOR, the integrated indexes of condition, vigor, organization and resilience), we proposed an assessment system based on the indicators monitored by unmanned aerial vehicles (UAVs)-UAVCVOR, and tested the feasibility of UAVCVOR at typical household pastures on the Qinghai-Tibetan Plateau, China. Our findings show that: (1) the key indicators of GHA could be measured directly or represented by the relative counterpart indicators that monitored by UAVs, (2) there was a significantly linear relationship between CVOR estimated by field- and UAV-based data, and (3) the CVOR decreased along with the increasing grazing intensity nonlinearly, and there are similar tendencies of CVOR that estimated by the two methods. These findings suggest that UAVs is suitable for GHA efficiently and correctly, which will be useful for the protection and sustainable management of grasslands. [ABSTRACT FROM AUTHOR]

Lakes within river-floodplain ecosystems are key biodiversity refuges majorly threatened by eutrophication and hydrologic river-lake fragmentation. However, an integrative index, specifically designed to comprehensively assess the health of floodplain lakes, considering multiple biological taxa and major stressors, remains unavailable. Based on biological data collected from 68 isolated lakes in the eastern plain lake region of China, we constructed a reliable index for assessing floodplain lake ecosystem health: Integrated Bioassessment Index (L-IBAI). The L-IBAI consists of components of overall health and species diversity, eutrophication, and hydrological connectivity and water level regimes. To construct the L-IBAI, we firstly used the observed species (SO)-area (A) model to predict the expected species richness (SE), and then developed observed to expected indices by calculating the SO/SE ratio for fish (F-O/E-SA) and benthos (B-O/E-SA). The health level thresholds for the other four indices, namely the ratio of Secchi depth and water depth (ZSD/ZM), chlorophyll a in phytoplankton (Chl a), the percent of rheophile fish species, and emergent macrophytes coverage, were determined using cumulative frequency curves. The final L-IBAI score was obtained by summing the weighted values of the three components mentioned earlier. The L-IBAI can significantly discriminate rural from urban lakes, and is a reliable index for assessing lake ecosystem health. Moreover, we developed three simplified three-index integrated bioassessment indices, which consists of three indices belonging to the three elements are also effective. The developed L-IBAI is flexible to be extended and applied to other floodplain lakes, and outcomes of health assessments for the eastern plain lakes in China helped to identify conservation and restoration priorities.

The Datong Lake is the largest freshwater aquaculture lake in Hunan Province. The macrofauna community and the environmental quality status were investigated in the Datong Lake in June 2019. Species composition, diversity and community structure of macrofauna were analyzed. The water quality was assessed by Shannon-Wiener diversity index (H'), biological index (BI) and Goodnight-Whitley index (IGW). A total of 32 species, belonging to 5 classes, 3 phyla were recorded. The dominant species were Bellamya aeruginosa, Paratanytarsus grimmii, Limnodrilus helveticus, Limnodrilus claparedianus, Limnodrilus hoffmeisteri, and Aulodrilus prothecatus. The values of Shannon-Wiener diversity, species evenness index and richness index were 1.51-3.62, 0.58-0.94 and 0.63-2.30, respectively. Compared with the historical data investigated in 1997 and 2008-2009, the species number, abundance and biomass of mollusks decreased, and the dominant group of mollusks showed a trend of succession from Bivalvia to Gastropoda. Assessment results by BI and IGW showed that most sites were in medium-heavy pollution status, and some sites were in light pollution status, while results of Shannon-Wiener index showed that most sites were in light pollution status. [ABSTRACT FROM AUTHOR]

Fluorescence dissolved organic compound indexes, such as Biological Index, Humification Index, and Fluorescence Index has been developed to identify the characteristic of organic compound properties in the water, as well as use phytoplankton biology index to monitor surface water quality. This study aimed to identify characteristic organic compounds and analyze the correlation between the biological phytoplankton index and the fluorescence dissolved organic carbon indexes in monitoring surface water quality. The results show a difference in the fluorescence of dissolved organic compounds along the surface water ecosystem during the dry and wet seasons. The upstream contains more allochthonous organic compounds, while the downstream contains more autochthonous organic compounds. According to the biological index value, the autochthonous matter is higher in the dry season, and the allochthonous humic compound is higher in the wet season, as identified by the humification index value. However, the uniformity index of phytoplankton and fluorescence dissolved organic compound indexes exhibited a lack of correlation, probably due to the fluorescence index applied particular intensity, which could not represent the phytoplankton properties. [ABSTRACT FROM AUTHOR]

The in vitro compatibility of the entomopathogenic fungus, Cladosporium cladosporioides BOU1, with the crude extract of three plants viz. Calotropis gigantea, Vitex negundo and Carissa macrocarpa at a concentration of 1% and 2% was investigated. The compatibility of the fungal isolate with the plant extracts was calculated using the biological index formula from the germination percentage, radial growth and spore production of BOU1. The compatibility of the plant extracts with the fungal isolate was also assessed based on the protease and lipase activities of the treated fungus. Both concentrations of plant extracts did not significantly inhibit the germination percentage, radial growth and spore production of BOU1 in a dose-depended manner. The average mean values of the biological index for the three plant extracts with two concentrations were more than 98%. The analyses of the data with the compatibility index formula suggest that irrespective of concentration, all three plant extracts were compatible with BOU1. When the plant extracts were added to the fungal isolate, the protease and lipase activities of the fungal isolate were not significantly inhibited compared to the untreated control. The reduction in all the variables of fungal growth and the enzymatic activity was less than 10% and 20%, respectively. From these findings, we can conclude that the fungal biocontrol agent C. cladosporioides BOU1 is compatible with the investigated plant extracts in terms of the fungal growth and enzymatic activities.

Aquatic macroinvertebrates are widely used as indicators for water quality assessment around the world. Modern strategies for environmental assessment implement molecular analysis to delimitate species of aquatic macroinvertebrates. Delimitation methods have been established to determine boundaries between species units using sequencing data from DNA barcodes and serve as first exploratory tools for taxonomic revisions. This is useful in regions such as the neotropics where aquatic macroinvertebrate habitats are threatened by human interference and DNA databases remain understudied. We asked whether the biodiversity of aquatic macroinvertebrates in a stream in Nicaragua, within the Central American Dry Corridor, could be characterized with biological indices and DNA barcoding. In this study, we combined regional biological indices (BMWP‐CR, IBF‐SV‐2010) along with distance‐based (ASAP, BIN) and tree‐based (GMYC, bPTP) delimitation methods, as well as nucleotide BLAST in public barcode databases. We collected samples from the upper, middle, and low reaches of the Petaquilla river. The three sites presented excellent water quality with the BMWP‐CR index, but evidence of high organic pollution was found in the middle reach with the IBF‐SV‐2010 index. We report a total of 219 COI sequences successfully generated from 18 families and 8 orders. Operational taxonomic units (OTUs) designation ranged from 69 to 73 using the four methods, with a congruency of 92% for barcode assignation. Nucleotide BLAST identified 14 species (27.4% of barcodes) and 33 genera (39.3% of barcodes) from query sequences in GenBank and BOLD system databases. This small number of identified OTUs may be explained by the paucity of molecular data from the Neotropical region. Our study provides valuable information about the characterization of macroinvertebrate families that are important biological indicators for the assessment of water quality in Nicaragua. The application of molecular approaches will allow the study of local diversity and further improve the application of molecular techniques for biomonitoring. [ABSTRACT FROM AUTHOR]

Wickered-constructed floating wetland in the Gedebage pond was built as an integrated tourist attraction with the floating mosque. According to the governing ordinance, it should conform to the quality standard requirements. This study aimed to assess the pollutant removal efficiency of constructed floating wetland from domestic waste in the Cinambo river as an influent on the pond and the pond's ecological status. The assessment of ecological status was based on three methods: 1) the physicochemical index using the pollution index (PI) and the water quality index (WQI), 2) the biological index using phytoplankton diversity including the trophic index, and 3) canonical correspondence analysis (CCA) describes the multivariate correlation between the physicochemical index and the biological index. The results indicated a pollutant removal efficiency of total dissolved solids (TDS) was 46.5-49.5%, of total suspended solids was (TSS) 33.5-39.8%f biochemical oxygen demand (BOD) was 34.0-37.3%, of chemical oxygen demand (COD) was 11.8-17.5%, of total nitrogen (TN), was 76.3-79.6%, of total phosphate (TP) 89.1-89.9%, of boron (B) was 29.7-54.5%, of detergent (MBAS) was 72.9-82.2%, and of dissolved oxygen (DO) was 2.8 to 3.6 times. The ecological status indicated the improvement of water quality from heavily polluted in influent to lightly polluted in the pond (PI) and changed from poor to fair (WQI), the same results with biological index were indicated in moderately polluted after treatment. However, trophic index results showed the pond was in eutrophic to hypertrophic condition. CCA indicated eutrophication was correlated to the abundance of Microcystis and Lyngbya genera. [ABSTRACT FROM AUTHOR]

The investigation on the compatibility of the indigenous isolate Lecanicillium saksenae (Kushwaha) Kurihara and Sukarno (ITCC 7714), a potent entomopathogen for the rice bug Leptocorisa oratorius (Thunberg), isolated from Vellayani soils of Kerala, India was undertaken with the prime objective of integrating it in the IPM package for sucking pest management in paddy. The insecticides recommended by Central Insecticide Board and Registration Committee (CIB & RC) for pest management in paddy were tested for compatibility at their recommended, half the recommended and double the recommended doses using the poisoned food technique. We found that, among the new generation insecticides tested, flubendiamide 39.35% SC, chlorantraniliprole18.5% SC, imidacloprid 17.8% SL and thiamethoxam 25% WG were found to be compatible with L. saksenae at all the three doses. Flubendiamide 39.35% SC and imidacloprid 17.8% SL were least inhibitive at recommended dose with the highest Biological index (BI) of 89. Of the old generation insecticides, dimethoate 30 % EC was compatible at the half and recommended doses, while malathion 50 % EC, quinalphos 25% EC and chlorpyrifos 20% EC were toxic to L. saksenae. Quinalphos 25 % EC was the highly inhibitive insecticide with a BI of 14-22, exhibiting a significant reduction in growth, sporulation as well as germination of the fungus. [ABSTRACT FROM AUTHOR]

The in vitro compatibility of the entomopathogenic fungus, Cladosporium cladosporioides BOU1, with the crude extract of three plants viz. Calotropis gigantea, Vitex negundo and Carissa macrocarpa at a concentration of 1% and 2% was investigated. The compatibility of the fungal isolate with the plant extracts was calculated using the biological index formula from the germination percentage, radial growth and spore production of BOU1. The compatibility of the plant extracts with the fungal isolate was also assessed based on the protease and lipase activities of the treated fungus. Both concentrations of plant extracts did not significantly inhibit the germination percentage, radial growth and spore production of BOU1. The average mean values of the biological index for the three plant extracts with two concentrations were more than 98%. The analyses of the data with the compatibility index formula suggest that irrespective of concentration, all three plant extracts were compatible with BOU1. When the plant extracts were added to the fungal isolate, the protease and lipase activities of the fungal isolate were not significantly inhibited compared to the untreated control. The reduction in all the variables of fungal growth and the enzymatic activity was less than 10% and 20%, respectively. From these findings, we can conclude that the fungal biocontrol agent C. cladosporioides BOU1 is compatible with the investigated plant extracts in terms of the fungal growth and enzymatic activities. [ABSTRACT FROM AUTHOR]

The Crop protection system is dominated by the use of synthetic insecticides however incorporation of fungal biocontrol agents (FBA) at lower doses is considered to consolidate the integrated pest management (IPM) program. The success of IPM is delimited and relies on the understanding of how its performance is affected by adverse effects on FBA by agrochemicals deployed for its management as well as of other pests and diseases. In this study, laboratory grade actives of three different insecticides used for the control of Tetranychus urticae were tested at different concentrations to determine their effects on germination, mycelial growth and sporulation of eight entomopathogenic fungal isolates under in vitro conditions. The fungal isolate with the most adverse effects on the biological index was further studied for underlying reasons of antagonism. This paper reports for the first time changes in conidial surface morphology, its germination and penetration capacity on mite cuticle, post insecticide treatment. Bioassays showed that all insecticide actives at their lowest concentration (12.5% MC) were most toxic to Beauveria bassiana P isolate. Ethion and chlorpyriphos were compatible with Hirsutella thompsonii PDBC-1 at 12.5% MC while propargite showed compatibility with B. bassiana MTCC 6097, Metarhizium anisopliae MTCC 4104 and Cordyceps fumosorosea MTCC 4636 at the same concentration. Further, SEM studies showed that post-insecticide treatments, there were structural deformations on the conidial surface with a decrease in its germination and germ tube penetration capacity on the cuticle of T. urticae. Future studies in this area will help in improving IPM along with overcoming insecticide resistance problems. [ABSTRACT FROM AUTHOR]

The role and importance of benthic organisms in the food chain and ecological pyramid of aquatic ecosystems is highly recognized. This study was conducted to investigate the benthic population and water quality of Karaj River, located in Alborz Province. In this study, a total of four stations along the river were selected and their benthic fauna were sampled seasonally. Samples were fixed with 4% formalin, isolated, identified, and counted in the laboratory. In the sampling procedure, 24 families, 5 categories and 5 orders were identified. The highest benthic density with 177 specimens (number per square meter) was reported in summer and the lowest benthic density with 105 specimens reported in winter. The benthic population and composition of Karaj River benthic was consisted of two classes of Oligocheata, Platyhelminthes and Coleoptera order and these groups had the highest density in all stations. During this study, the average Shannon-Wiener diversity index was 1.61. The highest Shannon-Wiener diversity index in the first station was 1.92, Based on the Hilsenhof Biological Index (HFBI), resulting that the water quality of Karaj River classified at the levels of good to desirable. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water quality is presented by its physicochemical and biological specification. The aim of this study was to analyze the physicochemical characteristic of waters (river, drinking, hybrid and pure water) including total hardness, magnesium, nitrite and ammonia (mg/L) which were determined based on the standard protocols of the EPA (2010) using photometer, Palintest, 8000. Furthermore, dissolved oxygen (mg/L), temperature (ºC) and pH were determined by oxygen meter, calorimeter and pH meter, respectively, with 3 repeats and in the limnology laboratory of Birjand University. In river water, the concentration of nitrogen is higher compared to other water sources due to the physicochemical reactions (especially due to the disposal of ammonia into water). For the hybrid water, consisting of drinking water plus pure water, the chlorine concentration (0.4 mg/L) was greater than the average (0.15 mg/L). The total hardness of the same (125 mg/L) was however lower than the average (185 mg/L). Finally, it is recommended that biological indicators such as the presence of rotifers, tubular cross-sectional fish, and salmon (which normally live in clean water) be used to assess the qualitative characteristics of the water. This is due to the fact that there are normally more living creatures in waters which can hold salts.

This research was conducted to determine the concentration of heavy metals (Cu, Pb, and Ni) in the sediments as well as the gill and muscle tissue of Siganus javus and two species of algae (Padina australis and Sargassum vulgare) collected from the Persian Gulf coasts of Bushehr province, which were studied using standard laboratory methods. The general form and trend of metal uptake at different stations in the gill and muscle tissue was Cu > Ni > Pb. The results of the study of metal uptake in both algae showed that the uptake of all three metals was higher in Padina species (Pb ˂ Cu ˂ Ni). The estimated daily intake (EDI), estimated weekly intake (EWI), allowable fish consumption rate limit (CRlim), and the target hazard quotients (THQ) for the consumption of this fish were also calculated. It was found that the concentration of heavy metals in the edible parts of the fish did not exceed the permissible limits proposed by the WHO, MAFF, JECFA, and NHMRC for human consumption, but the Ni concentration was higher than standard. The consumer risk indexes for non-cancerous diseases due to all metals were lower than standard. Also, the total risk index (HI) in this study was 0.065. [ABSTRACT FROM AUTHOR]

Background Periportal fibrosis (PPF) is the major pathological consequence of Schistosoma mansoni infection. The Coutinho index—the alkaline phosphatase (ALP) to platelet ratio ([ALP/upper limit of normality {ULN}]/platelet count [106/L] x 100)—was validated. Validation consisted of modest laboratory tests to predict advanced PPF. Methods A total of 378 individuals from an endemic area of Brazil with a previous history of the disease and/or a positive parasitological examination were evaluated. We used ultrasound examination as the gold standard for classification of the PPF pattern and measured the biological markers of the index. Results Forty-one individuals (10.8%) without PPF, 291 (77%) with moderate PPF and 46 (12.2%) with advanced PPF, were identified. ALP and platelet count were used for the index. The cut-off point ≥0.228 predicted the presence of fibrosis with an area under the receiver operating characteristic curve (AUROC) of 0.56, sensitivity of 68.6% and specificity of 46.3%. There was an absence of PPF in 46.3% of individuals without fibrosis and the presence of PPF in 68.5% of cases with moderate and advanced ultrasound fibrosis. The identification of advanced fibrosis with a cut-off point ≥0.316 revealed an AUROC curve of 0.70, sensitivity of 67.4% and specificity of 68.3%, thus confirming the advanced phase in 65.2% of cases compared with ultrasound. Conclusion The Coutinho index was able to predict advanced PPF in most individuals. It is valid as a new tool, uses routine laboratory tests and therefore is more accessible for screening patients with a severe form of the disease in endemic areas. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Fisheries is the property of University of Tehran and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Viticulture is one of the most important agricultural sectors in the Mediterranean area but also one with substantial impact on the soil ecosystem. Some of the most common practices in viticulture, such as tillage, inter-row management, fertilization and use of pesticides, can have important effects on soil communities. The latter significantly contribute to several fundamental soil processes such as decomposition, nutrient and carbon cycling, and microbiota regulation. In perspective, it is therefore necessary to assess the effects of agronomical practices on soil biological communities. The increasing shift towards organic viticulture is seen as a promising management model to maintain soil functionality and preserve soil biodiversity. Below, we present an appraisal of the main practices in conventional and organic viticulture and their possible effects on soil mesofauna. Understanding the extent to which organic practices contribute to maintaining/altering soil functionality and biodiversity is a fundamental step towards the development of an environmentally sustainable viticulture. [Display omitted] • Soil arthropod communities ensure the maintenance of pivotal soil functioning. • Viticulture is not immune to soil degradation and soil biodiversity loss. • Some of the most common viticultural practices may affect soil biodiversity. • Organic viticulture is seen as a promising option for soil preservation. • Studies are needed to unveil the real benefits of organic practices on soil biota. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the abundance of macrobenthic and their relationship with environmental factors in the sediments of the Gharehsou River and Gorgan Bay. Abundance and distribution of macrobenthic in 12 stations and three regions of Gharehsou River and its estuary, the northern and southern coastal part and parallel to the estuary in the deep part of Gorgan Bay, were evaluated using a Van Veen grab in triplicates during 2018-2019 seasonally. In this study, a total of 4414 specimens of macrobenthic from including 3 phylum, 6 order and 12 families identified. The largest number of microbenthic belonged to Streblospio gynobranchiata (7.35%), then Tubificidae with 24.2%. The lower abundances were also included Pontoporeia affinis (0.05%) and Pontogammarus rubustoides (0.1%). Season of spring with 30% had the highest abundance compared to other seasons. Then the summer season with 29% and the autumn season with 25% were in the next frequency. The lowest frequency was related to winter with 16%. The highest diversity index was in station 4 and the lowest was in station 1. According to these results, it was concluded that the macrobenthic in obtaining and different places have a large limit on the abundance and diversity index. If you use these communities to influence the environment, you have to consider them natural. [ABSTRACT FROM AUTHOR]

Zooplanktons have an important role in food chain of the aquatic ecosystems, which acts as a food chain link between producers (phytoplankton) and higher nutritional levels. The purpose of this research was to identify and study the zooplankton density in the southeastern basin of the Caspian Sea (Gorgan Bay). Sampling was performed seasonally and samples were collected by zooplankton net (36 cm and mesh size of 100µm) with three replications from three areas including: pan-cultures, Ashooradeh pier and entrance of sea water to the Bay. In this study, zooplankton groups belong to 16 species of 6 phylum were identified containing: Copepoda, Rotatoria, Protozoa, intermediate zooplankton (zoobenthose) and a group including other zooplankton groups. The mean Shannon diversity index during sampling time was 1.57±0.26, Margalef species richness index was 1.83±0.43, and for the uniformity index was 0.69±0.12. The lowest Shannon Diversity Index was 1.12 in the autumn station 6 was considered due to human activity, commuting boats (tourists and fish hunting), and the oil pollutants in this region, and the highest Margalef index was 2.76 in the spring station 2 and the Pielou's evenness index was highest for the winter at station 5 (0.92). Cluster analysis and non-metric multidimensional scaling showed the similarity of stations with each other based on abundance distribution of species in two distinct groups. Finding of research, could play an important role in environmental protection in the Gorgan Bay.

One of the problems for rivers and streams in Iran is related to dispersal of the waste effluents from trout farms. The aim of this study was to assess the effects of trout farm effluents on Zarin-Gol stream using macrobenthos communities, Helsenhoff, BMWP and ASPT indices. Sampling of macroinvertebrate was performed in six stations (entrance of fish farm, discharge and 500 far from fish farm) in three replicates using surber sampler in winter and spring, 2016. The number of total abundance of macroinvertebrate were counted 2179 belonging to 8 order, 30 families and 15 genus. The results showed that the trout farm effluents had significant effects on nitrite and dissolved oxygen. The highest value of BMWP and ASPT was obtained in station 1 in winter season, while the lowest value was obtained in stations 2 and 5 in spring season, considered asthe middle class in terms of water quality. The maximum value of Helsenhoff index was observed in station 2 (5.31) in winter season, considered as relatively weak class in terms of water quality. The result of indices showed a decrease in macrobenthos sensitive to pollution, and stations located after trout farms were more polluted than those located before farms, indicating lower water quality.

Background: Integrating fungal biocontrol agents into crop protection programs dominated by synthetic pesticides is an important first step towards developing an integrated pest management (IPM) program; however, their successful integration relies on an understanding of how their performance may be impacted by the remaining agrochemicals deployed for managing other pests and diseases. In this study we tested 10 formulated pesticides used in macadamia production at different concentrations to determine their effects on the germination, mycelial growth and sporulation of Metarhizium anisopliae and Beauveria bassiana in vitro. Further tests with laboratory‐grade actives of the noncompatible pesticides were conducted to determine whether any antagonistic effects were caused by the active constituent or by formulation additives. Results: At their registered concentrations, formulated trichlorfon, acephate and indoxacarb were compatible with M. anisopliae, whereas B. bassiana showed compatibility with formulated trichlorfon, acephate, indoxacarb, sulfoxaflor and spinetoram. Bioassays using laboratory‐grade active constituents indicated that the adverse impact of formulated beta‐cyfluthrin on both fungal species and that of formulated methidathion on B. bassiana is probably due to components of the emulsifiable concentrate formulations rather than their active constituents. Diazinon was the only insecticidal active that showed high toxicity to both fungal species. The two fungicides, carbendazim and pyraclostrobin, were toxic to both fungal species at all tested concentrations. Conclusion: Our results identify which pesticides used on macadamias in Australia are compatible and incompatible with entomopathogenic fungi. Future studies on pesticide degradation rates will help define the spray intervals required to eliminate these adverse effects. [ABSTRACT FROM AUTHOR]

Macroinvertebrates can provide an integrated picture of environmental changes. Health of rivers can be assessed based on measured changes in the ecological structure of macroinvertebrates. Using aquatic macroinvertebrates, we evaluated health of Mohammad-Abad River located in Golestan Province of Iran. Twelve sampling stations were selected along the river. Macroinvertebrates were sampled, and physicochemical parameters were measured at the same time. Twenty-seven families of macroinvertebrates were identified. They belonged to 6 orders of macroinvertebrates, Diptera with 86.82%, and had the highest frequency. Odonata (0.4%) had the lowest frequency. Canonical correlation analysis (CCA) indicates importance of nutrients in the distribution of different macroinvertebrates. Seventy-three percent of the variance in CCA was explained by nutrients and water temperature. Iranian Water Quality Index for Surface Water Resources Conventional (IRWQIsc) and Hilsenhoff Family-level Biotic Index (FBI), and biological monitoring working party/average score per taxon (BMWP/ASPT) consistently showed the same trend in our analyses. Our results showed high efficiency of water quality bio-evaluation for the river by measuring the macroinvertebrate communities, so that the results of the biological indices are consistent with the water quality index. Our method improves the costly, time-consuming and polluting methods that have been used in the past. Additionally, environmental changes due to a variety of land uses are better illustrated by our improved method. We conclude that FBI and BMWP/ASPT indices are suitable for assessing river health by macroinvertebrates. [ABSTRACT FROM AUTHOR]

Fresh Water Rivers are one of the most important aquatic ecosystems in arid and semi-arid regions of Iran in point of biodiversity and drinking water views. Damghanroud River is one of these rivers at Semnan province that during past years has been threatened by drought and anthropogenic pollutions. This river supplies some parts of drinking water of Damghan city and some vicinity villages. The aim of the present study is to consider Biological Index of the river; for this purpose, limnological and hydrobiological studies of the river were carried out. At this study, seven sampling stations were determined based on limnological standard method along the river; afterwards sampling of invertebrates (Biological Index) and water quality (BOD) were performed seasonally during study period. The results showed that the first station (Cheshmeh-Ali) is free of pollution while the fourth sampling station (Doab) is the most polluted region at the river because the first station has no pollutant resource but the fourth station directly receives wastewater of agricultural activities and rural wastewaters. According to biomonitoring and water BOD measurement findings, Damghanroud River has relatively polluted situation and is classified in β-mezosaprobe class and benthos biological index has been deteriorated at this river.

Oligonychus afrasiaticus (McGregor) is an important pest causing substantial economic losses to date palm fruits (dates). The application of mycopathogens with plant secondary metabolites, which may proceed synergistically is thus essential to augment sustainable management strategy for O. afrasiaticus. In this regard, extensive laboratory experimentation involving compatibility, synergism, and host defense was performed to develop stable pest management option. The toxin-pathogen compatibility assay results revealed compatible interaction (biological index = 79–95) of B. bassiana ARSEF 8465 against each tested concentration of commercially available (+)-α-Pinene that provide the opportunity to further explore the time and concentration dependent mortality and defense related enzymatic regulation analysis. The time-mortality response assays that mainly comprised of various proportions of B. bassiana ARSEF 8465 and (+)-α-Pinene revealed that the sole application of B. bassiana ARSEF 8465 (LC50 = 19.16 mg/mL), and (+)-α-Pinene (3.41 mg/mL) found to be least lethal compared with joint applications (LC50 ranged from 1.32–7.06 mg/mL). The treatments complied under Scheme IV (80% (+)-α-Pinene: 20% B. bassiana ARSEF 8465 Conidia) led to strong synergistic interaction (joint toxicity = 755). In addition, synergistic interactions greatly induced enzymatic activities of the studied antioxidants (CAT and SOD), and defense-related enzymes (GST and AchE). We concluded that join application of B. bassiana ARSEF 8465 and (+)-α-Pinene is a promising option for controlling Oligonychus afrasiaticus populations.

This study aims to develop a benthic macroinvertebrate multimetric index for assessing the ecological quality of streams in Northeastern Thailand. ANOSIM indicated that the benthic macroinvertebrate assemblage in both of each basin and each season were not significantly different (R = 0.09, p = 0.24 and R = 0.07, p = 0.35, respectively). The efficacy metrics of each basin consisting of the Mekong II, the Chi, and the Mun basins were integrated and calibrated. A total of 255 data sets of water physico-chemical and benthic macroinvertebrates during the dry period (cool and hot seasons) were obtained. The stream classification could be divided into three groups: the reference group (48 stations), the stressed group (42 stations), and the intermediate group (165 stations). Twelve out of 56 metrics have been considered as a core metric for the development of a biological index for quality streams in the Northeast, including Total taxa, EPT taxa, Ephemeroptera taxa, Coleoptera taxa, % EPT, % Chironomidae, % Tolerant individuals, % Intolerant individuals, Beck's index, HBI, Predator taxa, and Clinger taxa. Moreover, this metric set covered the structure and function of organisms including the diversity of species, community structure, tolerance/intolerance measures, functional feeding group, and habit. From the efficacy validation of the biological index, the results of stream assessment corresponded to the classification sites with the physico-chemical characteristics.

Aims: To assess the compatibility of alternative phytosanitary products (APPs) with the entomopathogenic fungus Beauveria bassiana (Bals.) Vuillemin. Methods and Results: The APPs used were Baicao, Orobor®, Topneem, Rotenat and Compostonat at concentrations recommended by the manufacturers (CR), and then half (1/2CR) and double (2CR). To evaluate the compatibility, the following parameters were analysed: germination, colony forming units (CFUs), vegetative growth and conidia production. Compatibility was assessed using rates of toxicity and biological index. The association of APPs and B. bassiana was also evaluated for pathogenicity against larvae of third instar Anagasta kuehniella Zeller (Lepidoptera: Pyralidae) (1·0 × 108 conidia per ml). The germination of conidia of B. bassiana was reduced only by the product Orobor®. The CFUs were not affected by any products. The colony diameter was reduced when in contact with the products Baicao and Orobor®. For conidia production per colony, all products reduced this parameter. None of the products affected the pathogenicity of the fungus on A. kuehniella. Conclusions: All APPs tested are compatible with B. bassiana. Significance and Impact of the Study: The natural products tested and used in the field are considered compatible with B. bassiana under laboratory conditions, making possible new studies and the use of these in insect control. [ABSTRACT FROM AUTHOR]

【Objective】 The relationship between growth and development and analysis of main biological characteristics of feed Brassica napus L. was studied to provide the theoretical basis for the large-scale cultivation in Ningxia. 【Method】 Huayouza 62 was taken as the test materials. Its main biological indexes were measured and analyzed from the seedling stage to the harvest stage. 【Result】 From correlation coefficient leaf number with plant height and stem diameter, the correlation coefficient were r = 0.985**and r = 0.981**respectively. In principal component analysis, the contribution rate of four biological indexes component were dry matter quality > fresh weight per plant > leaf number > chlorophyll content in the first principal; the contribution rate of four biological indexes are plant height > stem diameter > Area of max. Leaf > stem/leaf ratio in the second principal component. 【Conclusion】 The change of the biological index of feed Brassica napus L was a single‘S’curve. The number of leaf was a decisive factor for the size of plant. Plant height and stem diameter promoted growth. The first and second principal components can present the relevant information of eight biological indicators of the plant better. [ABSTRACT FROM AUTHOR]

Global ecological conditions existing in the streams of northern Tunisia are very unequal. In consideration of their appropriate management and restoration requirements, breeding populations of 28 Odonata species were studied over an annual cycle in twentyeight watercourses (22 permanent, 6 intermittent). In total, 7 363 larvae and 337 exuviae were collected. We developed a new indicator, the Tunisian Stream Odonatological Index (TSOI), to assess conservation aspects of Odonata biodiversity in African Mediterranean streams by analysing dragonfly communities. The TSOI operates at the species level. Taxonomic richness, voltinism, endemism, relative taxonomic distinctiveness, and regional conservation status (IUCN) are elements taken into account to design this index. Accordingly, presence of both Maghreb endemic and semivoltine species (Calopteryx exul, Platycnemis subdilatata, Aeshna cyanea, Boyeria irene, Gomphus lucasii, Onychogomphus costae, O. forcipatus, and O. uncatus) may provide useful information about the refuge quality of each habitat type for species with different biological features, and their interest level from a conservation point of view. The results of a first application of this approach are presented in the paper as well. As far as we know, a biodiversity conservation index based on benthic invertebrates in the African Mediterranean area has never before been proposed nor used. [ABSTRACT FROM AUTHOR]

With the rapid urban and industrial development, Taihu Lake and its adjacent wetlands had suffered serious pollution due to human activities. In order to assess sediment quality of the lake buffer zone of Zhushan Bay, Taihu Lake, macro fauna and sediment chemicals were analyzed at 33 sites from August 2013 to May 2014. A total of 79 macrofaunal species were identified, belonging to 3 phyla, 14 orders and 20 families. The most two dominant taxa were Oligochaeta (78%) and Chironomidae larva (19%). In terms of species richness, Chironomidae larva were the largest group (43 species), followed by Oligochaeta, Mollusca, Hirudmea, Decapoda and Polychaeta. Limnodrilus hoffmeisteri (accounting for 26.2%) was the most dominant species, which was one of the heavy pollution indicators in the study area. According to Biotic Index (BI), sediment quality was under serious pollution during August 2013 to March 2014, ranging from 7.98 to 8.81 while there was a declining trend for BI from March 2014 to May 2014, which indicated that sediment quality was under recovery. However, chemical indices showed that a continuous amelioration of sediment quality from December 2013 to March 2014, which was not consistent with biological assessment. This result indicated that there was a delay of the recovery for macrofauna compared with sediment chemicals. Correlation analysis showed that BI had significant relationship with sediment total nitrogen. The present study showed that in sediment quality assessment, macrofauna should be involved, which could provide more accurate results than sediment chemicals. [ABSTRACT FROM AUTHOR]

Fresh water rivers are one of the most important aquatic ecosystems in arid and semi-arid regions of Iran in viewpoint of biodiversity and drinking water. Damghanroud river is one of the rivers in the Semnan province that during past years has been threatened by drought and anthropogenic pollutions. This river supplies some parts of drinking water of Damghan city and some vicinity villages. The aim of the present study was biological index assessment of the Damghanroud river. At this study, seven sampling stations were determined based on limnological standard method along the river. Sampling of invertebrates and water were performed respectively to calculate biological index and biochemical oxygen demand (BOD) seasonally during the study period. The results showed that the first station (Cheshmeh-Ali) is free of pollution while the fourth sampling station (Doab) is the most polluted region at the river because the first station has no pollutant resource but the fourth station directly receives wastewater of the agricultural activities and rural wastewaters. According to biomonitoring and water BOD measurement findings, Damghanroud river has relatively polluted situation and is classified in ß-mezosaprobe class and benthos biological index has been deteriorated at this river. [ABSTRACT FROM AUTHOR]

Corsica is a French island in the western Mediterranean with numerous distinct geomorphological, landscape, and biological characteristics. These specific attributes, mostly related to insularity, are hardly taken into account by the biological indices currently recommended in the framework of the European Union Water Framework Directive “WFD” for assessing the ecological status of watercourses. Thus, this work has focused on developing an innovative biological index adapted to the specific context of territories such as Corsica, based on the Odonata group. In this context, imago sampling of Odonata was performed at 40 representative stations to assess the 33 major permanent rivers of the island. In parallel, various biological, hydrological, and physicochemical parameters affecting the ecological status of these organisms were recorded. The data collected on nearly 30 species of Odonata allowed for the accurate description of the typical populations of Corsican watercourses, highlighting this group's potential as a biological indicator. An indicator value was assigned to the 12 species identified as the most representative of these environments. The results were used to develop 5 biological indices based on simple statistical descriptors. The index that was found to be the best for assessing the ecological status of the watercourses, as indicated by correlation tests, was named “ Odonata Community Index – Corsica” (OCIC), and was finally confronted with the 5 biological indices recommended by the WFD and currently used in Corsica. The results of this study confirm the significant potential of the OCIC index compared to other “official” indicators, that are limited in they do not accurately assess all territories. The results of our tests indicate that this new index using Odonata group appears to be a credible method that could potentially improve the evaluation system currently used for monitoring the ecological quality of watercourses in Corsica. [ABSTRACT FROM AUTHOR]

Our researches have been made on brown forest soil that had been used in long-term experiments set up according to specified fertilization system for over 30 years. We have chosen those experiment variants in which quantities of nitrogen fertilizers were gradually increased. The soil samples taken from 0 cm to 30 cm depth were used to determine biological indexes of nitrogen availability (aerobic and anaerobic incubation). The same samples were also used for pot experiments with oat. Plant and soil parameters obtained in controlled conditions were used for determination of biological indexes reliability in measuring the soil nitrogen availability. On the grounds of correlation analysis, it can be concluded that biological index of nitrogen availability achieved by the anaerobic incubation (without substraction of the initial content of available nitrogen) of the investigated brown forest soil is the reliable indicator of soil nitrogen availability. That is not the case with the aerobic incubation in which reliability has not been established.

Based on plankton data at two sampling sites of subtidal zone of Shenzhen Bay during 2016--2017, temporal-spatial changes of species composition and quantity, dominant species, diversity index and evenness were analyzed. The results showed that eco-environment quality of plankton in Shenzhen Bay was in general level. [ABSTRACT FROM AUTHOR]

The size of the sieve mesh opening use to hold the benthic macrofauna could affect certain biotic indicators utilized to describe the ecological status of a given benthic system. The objective of this study was to determine the effect that the lower limit of the mesh opening could have in the estimation of species richness, Shannon-Wiener diversity index and AZTI marine biotic index (AMBI). Data was collected from sediment samples obtain in stations located in and out (reference) of two mussel farms from Reloncaví Sound. The samples were sieved through two sizes of mesh opening: 1 mm and 500 μm. The benthic macrofauna was identified and quantified as ≥500 μm and ≥1 mm. The AMBI, Shannon-Wiener diversity index (log2) and species richness was estimated. Indicators estimated from information obtained with the ≥500 μm and ≥1 mm mesh were compared through a t test. The most abundant species on both localities was the polychaete Chaetozone setosa, assigned to the ecological group GE IV, and the Ostracoda Class, assigned for Chilean experts to the ecological GE 2. Significant differences were observed only in species richness at stations within the culture (in the Center 2). According to the estimated biological indicators the ecological status of benthic systems under the farms is acceptable based on the limits established for diversity and AMBI. Using a mesh size of 500 μm results in larger abundances of opportunistic species, but this change had no effect on the classification of the ecological status of the benthic system. [ABSTRACT FROM AUTHOR]

Industrial effluents discharged into the environment may have ecotoxic effects even if they come up to regulatory standards. Chemical evaluation of treatment performance by end-of-pipe treatment systems is thus not sufficient, especially when mixtures of metallic and organic contaminants are concerned. Given that contamination may alter biological characteristics of the environment, biomonitoring studies may provide information on integrated ecotoxical effects. However, there is a need for bioassays purpose-designed for direct use at industrial sites. Many biomonitoring tools already exist and have been proved to be efficient for evaluating the ecotoxicity of contaminated waters, but most of them require laboratory equipment. In this study, an experiment in microcosms under controlled conditions of pollution was carried out to assess the morphological responses of five helophytes exposed to mixtures of organic and/or metallic pollutants. The criteria of plant growth and development, i.e. aerial elongation and leaf senescence, that were the most relevant for reflecting the ecotoxicity of contaminant mixtures and that could be monitored on-site with a user-friendly method, were then selected. Focusing on these selected criteria, a new bioindicator tool, named the Helophyte Development Index (HDI), was created. Our results suggest that the HDI is a promising tool to use on-site for assessing the ecological state of waters released in aquatic environment by industrial factories, following the recommendations of the European Water Agency. [ABSTRACT FROM AUTHOR]

Les eaux du bassin de la Semois belge ont été étudiées, en 25 stations, sous différents aspects complémentaires : chimie, diatomées et invertébrés benthiques. Les méthodes utilisées sont l'indice de pollution organique (IPO, LECLERCQ et VANDEVENNE, 1987), un indice diatomique (ID, LECLERCQ, non publié) et l'indice biologique global normalisé (IBGN, AFNOR, 1992). Grâce aux analyses chimiques et diatomiques, nous décrivons différents types d'eaux naturelles, à minéralisation croissante, et différents niveaux de pollution et d'eutrophication. Nous présentons une carte d e qualité détaillée, à l'usage des gestionnaires. Les diatomées apparaissent comme les bioindicateurs les plus fiables pour ces paramètres. Les invertébrés sont moins intéressants à utiliser. Ils sont pratiquement insensibles au type de minéralisation de l'eau (tout au moins au niveau de la famille, qui est le seul niveau d'identification possible en routine), mais ces organismes peuvent être plus sensibles au facteur substrat qu'à la pollution organique, conduisant alors à des estimations erronées.