The diversity of Samoa’s freshwater macroinvertebrates remains largely unexplored, with past studies focusing on specific species without comprehensive cataloguing. This research evaluated the health of Upolu Island...The diversity of Samoa’s freshwater macroinvertebrates remains largely unexplored, with past studies focusing on specific species without comprehensive cataloguing. This research evaluated the health of Upolu Island’s rural rivers through macroinvertebrate analysis, particularly in the Le Afe and Mulivaifagatoloa Rivers. Collaborating with Samoa’s Water Resources Division in the Ministry of Natural Resources and Environment (MNRE), three sites along each river were sampled, representing a gradient from pristine to anthropogenically impacted areas. A total of 2953 macroinvertebrates were collected and classified into five categories using established identification keys. The Macroinvertebrate Community Index (MCI) and Quantitative Macroinvertebrate Community Index (QMCI) were applied for analysis. The results showed no clear pattern of pollutant-sensitive species prevalence or decline in less disturbed rivers. High MCI scores with low QMCI values indicated numerous low-scoring species, while the opposite suggested a richness of high-scoring taxa. Although MCI and QMCI are tools for monitoring freshwater health, this study lays the groundwork for future research to categorize Samoan macroinvertebrates and assign tolerance scores based on their presence in varying river conditions. .展开更多
Benthic macroinvertebrate communities in Spartina alterniflora zones in the Yangtze Estuary, in China, were investigated seasonally in 2005, and their structure and biodiversity were analyzed. Twenty-one species were ...Benthic macroinvertebrate communities in Spartina alterniflora zones in the Yangtze Estuary, in China, were investigated seasonally in 2005, and their structure and biodiversity were analyzed. Twenty-one species were identified, across four Classes; 10 species of Crustacea, five species of Polychaeta, five species of Gastropoda, and one species of Lamellibranchia. Dominant species included： Assiminea sp., Notomastus latericeus, Cerithidea largillierl, Gtauconome chinensi and Gammaridae sp. Functional groups were comprised of a phytophagous group and a detritivorous group. The average density of all benthic macroinvertebrates was 650.5 ±719.2 inds/m^2 in the survey area. The high value of the standard deviation of the average density was a result of abundant Assiminea sp. at Beihu tidal flats. The average density of macroinvertebrates from Beihu tidal flat, Chongming Dongtan to Jinshanwei tidal flat decreased gradually. There was significant difference between compositions and abundance of macroinvertebrates along the estuary gradient （P 〈 0.05）. The density and biodiversity were highest in summer and lowest in winter. The mean biomass of macroinvertebrates was 20.8 ± 6.1 g/m^2. Biomass changed seasonally in the same way as density, with the change in biomass being： summer （Aug.） 〉autumn （Oct.） 〉spring （Apr.） 〉 winter （Dec.）. A BIO-ENV analysis showed that the mean grain size of sediment, height of Spartina and salinity were the ma- jor factors which affected the structure of the macroinvertebrate community. Variations in the community structure were probably caused by the population dynamics of S. alterniflora along with the variation in sampling time and location.展开更多
This study presents findings of the first systematic analysis of aquatic biotic assemblages in the source region of the Yellow and Yangtze Rivers. It provides an initial basis with which to select representative organ...This study presents findings of the first systematic analysis of aquatic biotic assemblages in the source region of the Yellow and Yangtze Rivers. It provides an initial basis with which to select representative organisms as indicators to assess the aquatic ecological status of rivers in this region. Macroinvertebrates are considered to be good indicators of long-term environmental changes due to their restricted range and persistence over time. Field investigations of macroinvertebrates were conducted in August 2009 in the source region of the Yellow River, and in July 2010 in the source region of the Yangtze River. Altogether 68 taxa of macroinvertebrates belonging to 29 families and 59 genera were identified. Among them were 8 annelids, 5 mollusks, 54 arthropods and 1 other animal. In the source region of the Yellow River, taxa number, density and biomass of macroinvertebrates were 50, 329 individuals m2 and 0.3966 g dry weight m2, respectively. Equivalent figures for the source region of the Yangtze River were 29, 59 individuals m2 and 0.0307 g dry weight m-2. The lower benthic animal resources in the source region of the Yangtze River are ascribed to higher altitude, higher sediment concentration and wetland degradation. Preliminary findings of this exploratory study indicate that hydroelectric power stations had a weak impact on benthic dwellers but wetland degradation caused by a series of human activities had a catastrophic impact on survival of macroinvertebrates. Ecological protection measures such as conservative grazing and vegetation management are required to minimize grassland degradation and desertification, and reduce soil erosion rate and river sediment discharge.展开更多
The focus of this study was to investigate the macroinvertebrate community in surface mine wetlands. Nine wetlands were sampled for macroinvertebrates from July 1993 through May 1994.These sites represented a range of...The focus of this study was to investigate the macroinvertebrate community in surface mine wetlands. Nine wetlands were sampled for macroinvertebrates from July 1993 through May 1994.These sites represented a range of physical,chemical, and biological parameters. Macroinvertebrates were found in all sites;a total of 14 orders, 40 families,and 70 genera were identified in the samples. Insects were the most common invertebrates,and most functional feeding groups were represented. Predators dominated with 63% of the taxa, followed by the collector/gathers with 20%,shredders 14%, and scrapers 3%. Sites differed in the number of taxa inhabiting them.Richness ranged from 10 genera to 52.The lowest richness was found in two seasonal wetlands that were dry for the majority of the year. A permanently flooded site with no water quality problems and a dense growth of aquatic plants had the highest richness.展开更多
As a less time-consuming procedure, subsampling technology has been widely used in biological monitoring and assessment programs. It is clear that subsampling counts af fect the value of traditional biodiversity indic...As a less time-consuming procedure, subsampling technology has been widely used in biological monitoring and assessment programs. It is clear that subsampling counts af fect the value of traditional biodiversity indices, but its ef fect on taxonomic distinctness(TD) indices is less well studied. Here, we examined the responses of traditional(species richness, Shannon-Wiener diversity) and TD(average taxonomic distinctness: Δ +, and variation in taxonomic distinctness: Λ +) indices to subsample counts using a random subsampling procedure from 50 to 400 individuals, based on macroinvertebrate datasets from three dif ferent river systems in China. At regional scale, taxa richness asymptotically increased with ?xed-count size; ≥250–300 individuals to express 95% information of the raw data. In contrast, TD indices were less sensitive to the subsampling procedure. At local scale, TD indices were more stable and had less deviation than species richness and Shannon-Wiener index, even at low subsample counts, with ≥100 individuals needed to estimate 95% of the information of the actual Δ + and Λ + in the three river basins. We also found that abundance had a certain ef fect on diversity indices during the subsampling procedure, with dif ferent subsampling counts for species richness and TD indices varying by regions. Therefore, we suggest that TD indices are suitable for biodiversity assessment and environment monitoring. Meanwhile, pilot analyses are necessary when to determine the appropriate subsample counts for bioassessment in a new region or habitat type.展开更多
The Nokoue Lake is the largest lake of Benin Republic and it is also considered as one of the most productive lagoon ecosystems in West Africa. This productivity is decreasing and thus raises productivity issue for a ...The Nokoue Lake is the largest lake of Benin Republic and it is also considered as one of the most productive lagoon ecosystems in West Africa. This productivity is decreasing and thus raises productivity issue for a better management and conservation. Macroinvertebrate can be useful for this purpose. A study was conducted to assess the spatial variation of macroinvertebrates during high flood period. A total of 3892 macroinvertebrates of fresh and brackish water were sampled during the survey. Structural analysis of the macroinvertebrate community revealed that it was made up of 16 orders, 48 families and 66 genera dominated by Insecta compared to Mollusca, Crustacea and the Annelida. Insects were dominated by Diptera (Chironomus sp. and Tanytarsus sp.), Coleoptera (Dystiscidae) and accounted for 57.1% of the sampled population. Mollusca, Crustacea, Annelida and Arachnida were the following most abundant and represented 23.9%, 10.7%, 8.1% and 0.2% of the total population, respectively. The Evenness index of Pielou was higher on the Station 8 (0.91 - 0.97), close to Oueme River. However, no significant difference (p > 0.05) was observed neither between station nor between month on the Shannon-Wiener index (2.06 - 4.31), Simpson index (0.04 - 0.40) and the taxa number (10 - 27). Macroinvertebrate assemblages and composition were primarily due to changes in water quality dependent on hydroclimatic changes and probably to anthropogenic actions. This suggests the need for real investigation of the macroinvertebrate biological capacity when formulating conservation strategies for the Nokoue Lake.展开更多
Estimating recovery times from pollution incident is an important issue of targeted biomonitoring programs.In the present study,the impact and recovery of macroinvertebrate communities from a cadmium wastewater discha...Estimating recovery times from pollution incident is an important issue of targeted biomonitoring programs.In the present study,the impact and recovery of macroinvertebrate communities from a cadmium wastewater discharge in the Longjiang River,Guangxi,China,in early January 2012 were studied based on 83 samples collected in fi ve surveys within 20 months after the incident.The pollution aff ected seriously the local aquatic biota,and consequently,the invertebrate abundance and species richness were reduced considerably.Twelve months later,the taxonomic number of macroinvertebrates began to increase.However,sensitive taxa remained rare.Twenty months later,the taxon richness and abundance of macroinvertebrates increased signifi cantly compared to those in the previous four time points.To explore the possible time-scale over which pre-disturbance conditions might occur,we chose four diff erent typical metrics of taxa richness(total taxa number,cumulative taxa number,taxa number per samples,and the Shannon-Wiener diversity index)and extrapolated modeled recovery trajectories.Target values for the four metrics were set at average values for sites from the nearby Lijiang River,which were used as a reference.Assuming a continued linear trajectory,the recovery times were estimated to be 52,39,39,and 31 months,respectively,which was roughly 3-5 years.This is consistent with results from recovery times from other studies of acute pollution cases,but contrasted strongly to the much longer recovery times associated with chronic pollution from groundwater contamination and mine-tailing runoff.展开更多
In this study conducted in the coastal zone of Cameroon, biological indices and functional feeding groups of benthic macroinvertebrates were used to assess the health status of two urban streams. For a better diagnosi...In this study conducted in the coastal zone of Cameroon, biological indices and functional feeding groups of benthic macroinvertebrates were used to assess the health status of two urban streams. For a better diagnosis, two streams located in coastal forest zone were used as a reference. Benthic macroinvertebrates were sampled monthly over a 3-month period (from May to July 2017) in six urban stations and six forest stations. Measurements of the physicochemical variables were done simultaneously. Physicochemical analysis revealed that urban streams are strongly polluted with high content of decaying organic matters, while forest streams are slightly polluted as indicated by the Principal Component Analysis. Concerning benthic macroinvertebrates, urban streams are poorly diversified with the proliferation of taxa tolerant to water pollution and belonging to the functional feeding groups of collectors-gatherers. Inversely, forest streams are more diversified and dominated by sensitive taxa, most belonging to the functional feeding groups of predators and shredders. These marked differences between biological indices and feeding mode of benthic macroinvertebrates in forest and urban rivers confirm the reliability of benthic macroinvertebrates as good indicators of freshwater ecosystem in the coastal zone of Cameroon.展开更多
Reed pans are a very uncommon type of endorheic wetland, and as such the amount of information available is very limited. Thus, they are being impacted on by various agricultural, livestock and other anthropogenic act...Reed pans are a very uncommon type of endorheic wetland, and as such the amount of information available is very limited. Thus, they are being impacted on by various agricultural, livestock and other anthropogenic activities. The objectives of this study were to determine the spatial and temporal variations of macroinvertebrate community structures in reed pans and the environmental factors (i.e., water quality) responsible for the maintenance of these structures. Reed pans were studied over four different seasons, during which time subsurface water, sediment and macroinvertebrate samples were collected and analyzed. The reed pans studied showed that the macroinvertebrates were able to reflect various changes in reed pans with regard to seasonal variability and anthropogenic impacts on water quality. These anthropogenic impacts caused the disappearance of sensitive macroinvertebrate taxa and the increase of tolerant macroinvertebrate taxa.展开更多
Taudaha Lake is one of the important wetlands in Nepal, as it provides critical habitats for thousands of migratory birds and fishes. Despite being a critically important water body, there is a lack of detail chemical...Taudaha Lake is one of the important wetlands in Nepal, as it provides critical habitats for thousands of migratory birds and fishes. Despite being a critically important water body, there is a lack of detail chemical and biological studies on this lake. The present study investigates the effects of seasonal water quality variations in distribution and abundance of macroinvertebrates in Taudaha Lake, during four different seasons in 2006. The results indicate that all the water quality parameters, except secchi depth, and total alkalinity, significantly varied among seasons. The gross primary productivity of the lake also significantly varied among the seasons, with highest primary production during summer (3.92 ± 0.18 gC/m<sup>3</sup>/day) and lowest during spring (2.44 ± 0.67 gC/m<sup>3</sup>/day). A total of 2166 individual benthic macroinvertebrates from 10 families and 7 orders were collected during the study period. Unlike water quality parameters, the macroinvertebrate species composition did not vary significantly among the seasons. The results suggested that the change in lake water quality did not have significant impacts on community metrics such as species diversity, species richness, and species evenness.展开更多
The impact of land use changes on watercourses is poorly documented in Cameroon. Therefore, this study examines the effects of agriculture and urbanization on water quality, the structure and functional organization o...The impact of land use changes on watercourses is poorly documented in Cameroon. Therefore, this study examines the effects of agriculture and urbanization on water quality, the structure and functional organization of macroinvertebrates of streams in the coastal zone of Cameroon. Nine sampling stations including three per catchment area with different land occupations (agricultural, urban and forest) were selected. Benthic macroinvertebrates were sampled monthly from February to July 2018 and the physicochemical variables were measured simultaneously. The urban and agricultural streams showed highly polluted waters with high nutrient and suspended matter content, whereas the forest stream waters are moderately polluted. In addition, the hierarchical ascending classification indicated a proximity in water quality between the agricultural and forest streams for which the main physicochemical variables did not vary significantly. With regards to macroinvertebrates, the forest watercourse is characterized by the proliferation of pollution-sensitive taxa, high diversity indices and complex trophic structuring, indicating its good ecological status. In contrast the urban watercourse, heavily polluted is characterized by low diversity indices reflecting a simplification of the structure of stands dominated by the pollution-tolerant collector-gatherer stands. The majority of biological indices and functional feeding groups were not significantly different between the agricultural and forest streams, suggesting a less pronounced impact of agriculture on macroinvertebrates. Our results showed that, riparian vegetation even though constituted of perennial crops, reduces the effects of agricultural inputs on streams and promotes the establishment of diversified macroinvertebrate communities.展开更多
The area of the city of Meknes (Morocco) undergoes anthropic pressure, which acts mainly on the rivers. River water is used, without preliminary treatment, for farm irrigation. A study of the impacts of anthropogenic ...The area of the city of Meknes (Morocco) undergoes anthropic pressure, which acts mainly on the rivers. River water is used, without preliminary treatment, for farm irrigation. A study of the impacts of anthropogenic activities on the distribution and biodiversity of benthic macroinvertebrates and water quality of the Boufekrane River (Meknes) was conducted. Four pristine stations from the upstream and two stations at the downstream receiving anthropogenic impacts were selected along the River. For 12 consecutive months (from January to December 2010), based on the SEQ-V.2 scoring system, water quality index classes, the upstream stations recorded significantly higher biological monitoring scores and better water quality indices than those of the downstream. Four variables are involved actively in the individualization of the physico-chemical environment: COD, dissolved oxygen, TSS and temperature. The total number of macrobenthic taxa and their overall richness indices and diversity indices were significantly higher at the upstream stations than at the downstream stations. The relationships between the physicochemical and the macrobenthic data were investigated by biotypology analysis (PCA and FCA) and Pearson correlation analysis. The analyses showed that the richness and diversity indices were generally influenced by the total suspended solids, chemical oxygen demand and the electric conductivity of the river water. This study also highlighted the impacts of anthropogenic activities on the distribution and species diversity of macrobenthic invertebrate. Some sensitive (Trichoptera and Ephemeroptera) and resistant species (Oligochaeta such as Tubifex sp.) are identified as potential bioindicators of clean and polluted river ecosystems, respectively, in Morocco rivers. The data obtained in this study supported the use of the bioindicator concept (Innovative Biotechniques for controlling water quality) for North Africa rivers because it is more efficient than conventional methods.展开更多
The influence of water quality on the variation patters of benthic macroin-vertebrate communities in the lakes in the central highlands of Peru was eva-luated. Samples of water and sediments were collected in 23 diffe...The influence of water quality on the variation patters of benthic macroin-vertebrate communities in the lakes in the central highlands of Peru was eva-luated. Samples of water and sediments were collected in 23 different sam-pling sites last 2017. The physiochemical variables of water quality deter-mined on site were: DO, TDS, EC, temperature and pH. The results obtained revealed that the physiochemical indicators are within the environmental quality standards for water, except COD and BOD5. Regarding the benthic macroinvertebrates, four phyla were identified wherein the most common is the phylum Arthropoda having the abundance and richness of taxa. The PCA reduced the variables to a few significant components that caused variation in water quality between lakes. The cluster analysis in relation to the relative abundance of benthic macroinvertibrates grouped the 22 sampling sites into three groups with the similar characteristics. The PCoA analysis of the ben-thic macroinvertebrate communities showed a clear separation of sites. The SIMPER analysis at the family-level showed the distribution of the most common species. Therefore, at a significance level of 0.01 it demonstrates that there are significant differences between the number of species and abun-dance of the areas that were evaluated.展开更多
Marsh flooding and drying may be important factors affecting aquatic macroinvertebrate density and distribution in coastal freshwater marshes. Limited availability of water as a result of drying in emergent marsh may ...Marsh flooding and drying may be important factors affecting aquatic macroinvertebrate density and distribution in coastal freshwater marshes. Limited availability of water as a result of drying in emergent marsh may decrease density, taxonomic diversity, and taxa richness. The principal objectives of this study are to characterize the seasonal aquatic macroinvertebrate assemblage in a freshwater emergent marsh and compare aquatic macroinvertebrate species composition, density, and taxonomic diversity to that of freshwater marsh ponds. We hypothesize that 1) freshwater emergent marsh has lower seasonal density and taxonomic diversity compared to that of freshwater marsh ponds;and 2) freshwater emergent marsh has lower taxa richness than freshwater marsh ponds. Seasonal aquatic macroinvertebrate density in freshwater emergent marsh ranged from 0 organisms/m2 (summer 2009) to 91.1 ± 20.53 organisms/m2 (mean ± SE;spring 2009). Density in spring was higher than in all other seasons. Taxonomic diversity did not differ and there were no unique species in the freshwater emergent marsh. Our data only partially support our first hypothesis as aquatic macroinvertebrate density and taxonomic diversity between freshwater emergent marsh and ponds did not differ in spring, fall, and winter but ponds supported higher macroinvertebrate densities than freshwater emergent marsh during summer. However, our data did not support our second hypothesis as taxa richness between freshwater emergent marsh and ponds did not statistically differ.展开更多
The Blue River Main wastewater treatment facility (WWTF) discharges into the upper Blue River (725 km2), and is recently upgraded to implement biological nutrient removal. We measured biotic condition upstream and dow...The Blue River Main wastewater treatment facility (WWTF) discharges into the upper Blue River (725 km2), and is recently upgraded to implement biological nutrient removal. We measured biotic condition upstream and downstream of the discharge utilizing the macroinvertebrate protocol developed for Kansas streams. We examined responses of 34 metrics to determine the best indicators for discriminating site differences and for predicting biological condition. Significant differences between sites upstream and downstream of the discharge were identified for 15 metrics in April and 12 metrics in August. Upstream biotic condition scores were significantly greater than scores at both downstream sites in April (p = 0.02), and in August the most downstream site was classified as non-biologically supporting. Thirteen EPT taxa (Ephemeroptera, Plecoptera, Trichoptera) considered intolerant of degraded stream quality were absent at one or both downstream sites. Increases in tolerance metrics and filtering macroinvertebrates, and a decline in ratio of scrapers to filterers all indicated effects of increased nutrient enrichment. Stepwise regressions identified several significant models containing a suite of metrics with low redundancy (R2 = 0.90 - 0.99). Based on the rapid decline in biological condition downstream of the discharge, the level of nutrient removal resulting from the facility upgrade (10% - 20%) was not enough to mitigate negative effects on macroinvertebrate communities.展开更多
The unique challenges associated with sampling of macroinvertebrates in flashy urban streams create a methods gap. These streams form isolated pools for much of the year, interspersed with spates that scour and deposi...The unique challenges associated with sampling of macroinvertebrates in flashy urban streams create a methods gap. These streams form isolated pools for much of the year, interspersed with spates that scour and deposit excessive amounts of sediment. Commonly used stream grab sampling methods, such as nets and Hess and Surber fixed-area samplers, work well in wadable streams with perennial flow. Deployed samplers (Hester-Dendy, gravel tray) can be used in waters with or without flow. We evaluated three methods which don’t require stream flow: modified Hester-Dendy (MHD), gravel tray, and bucket (a type of cylinder grab sample method), for their potential use in bioassessment of a project involving daylighting of a 180-m culvert on Congress Run, a flashy urban tributary to Mill Creek in Cincinnati, Ohio. Method efficacy was measured using three criteria: usability (level of effort and recoverability of samplers), variability, and community retrieval completeness. The bucket method required the lowest level of effort and had the highest sample recovery. The bucket sampler had the lowest variability for most metrics, including the critical metric of taxa richness, with a coefficient of variation (CV) of 20.9%. The MHD and tray samplers had taxa richness CVs of 42.9% and 53.9%, respectively. The bucket sampler also had the lowest CV (27.4%) for a multi-metric index. The bucket sampler performed best with respect to community retrieval completeness, with higher pooled and average taxa richness. The total number of taxa collected from all the replicate bucket grab samples (42) was greater than that collected by the HD and tray samplers combined (27). Multivariate analyses showed significant grouping with respect to methods and location. This study supports the bucket grab sampler method as a candidate for sampling of flashy urban streams.展开更多
Outdoor education programs frequently offer stream classes that teach students how to assess water quality based on the composition of aquatic macroinvertebrate communities. Repeatedly using the same site for stream c...Outdoor education programs frequently offer stream classes that teach students how to assess water quality based on the composition of aquatic macroinvertebrate communities. Repeatedly using the same site for stream classes can cause disturbance that could negatively impact aquatic macroinvertebrates. However, the impact of outdoor education stream classes on short term temporal trends of aquatic macroinvertebrates has not been evaluated. Our objective was to quantify whether outdoor education stream classes caused localized and short-term impacts on the aquatic macroinvertebrate community. We sampled aquatic macroinvertebrates over a five day period in May 2014 from an impacted riffle subjected to repeated substrate disturbance by outdoor education stream classes and an unimpacted riffle that was not subjected to stream classes within an agricultural stream in central Ohio. We did not observe a difference in macroinvertebrate community response variables between different time periods or among days within the impacted riffle as part of our within riffle analysis. We documented that macroinvertebrate abundance and dorsoventrally flattened clinger abundance was greater within the unimpacted riffle than the impacted riffle. Macroinvertebrate evenness was greater in the impacted riffle than the unimpacted riffle. In the impacted riffle percent clingers was greater on Monday than on Friday. Conversely, in the unimpacted riffle percent clingers was greater on Friday than on Monday. Our results indicated that outdoor education stream classes did not alter short term temporal trends of macroinvertebrate community structure within an impacted riffle, but the stream classes resulted in differences in community structure between an impacted and unimpacted riffle. Our results suggest that outdoor education centers should avoid repeatedly using the same site for their stream classes to prevent negatively impacting aquatic macroinvertebrates.展开更多
Investigations on biological capacity of water quality of macroinvertebrate community are very uncommon, and such as the amount of information available on the Nokoue Lake (the largest lake of Benin) is very limited. ...Investigations on biological capacity of water quality of macroinvertebrate community are very uncommon, and such as the amount of information available on the Nokoue Lake (the largest lake of Benin) is very limited. This information gap needs to be filled for better management of the Nokoue Lake. The goal of this study was to evaluate the possibility of using the macroinvertebrate community structures in Nokoue Lake and the environmental factors responsible for the maintenance of these structures. Nokoue Lake was studied over three months, during high flood period in which time subsurface water and macroinvertebrate samples were collected and analyzed. A study showed that the macroinvertebrate assemblages was done according to ecological gradients as pH, conductivity, TDS, salinity, chlorophyll a and probably to anthropogenic actions (nutriments). Better than the percentage of insects, the percentage of Chironomidae informed very well about macroinvertebrate assemblages. To assess the biological health of the environment, the Family Biotic Index (FBI) turns out to be more appropriate than diversity indices that do not take into account the intermediate pollution. Organic pollution revealed by the FBI probably affects the aquatic life.展开更多
The Affon River is one of the important rivers of the Ouémé River whose benthic diversity remained unknown. The present study aims to make the relationship between macroinvertebrates and physico-chemical par...The Affon River is one of the important rivers of the Ouémé River whose benthic diversity remained unknown. The present study aims to make the relationship between macroinvertebrates and physico-chemical parameters to access water quality of the Affon River. The measurement of physico-chemical parameters (temperature, pH, conductivity, transparency, depth and TDS, dissolved oxygen, ammonium, nitrite and phosphate) and the sampling of macroinvertebrates using a Surber net were carried out during floods in eight stations. A principal component analysis (PCA) and canonical correspondence analysis (CCA) were used. The indices of Shannon, Piélou, Simpson, Hilsenhoff, EPT and EPT/Chironomidae were used to assess the level of water pollution. The study identified 9755 macroinvertebrates divided into 4 classes, 14 orders and 49 families. Pollution-sensitive families (14 families) that are organic pollution indicators, as well as pollution-tolerant families (Chironomidae, Limnaeidae, Bithynidae, Physidae) were captured. Chironomidae were the most predominant and abundant family (FO = 100%). The predominance of Chironomidae coupled with the rarity of the Ephemeroptera, Trichoptera and Plecoptera would reflect the poor quality of the Affon River waters. The principal components analysis yielded groups of associations: The first group of stations Taneka 2 and 3 characterized by high values of ammonium and phosphate;and low values of conductivity and TDS;the second group of Tanéka 1 and Kolokondé 1 stations with low values of pH, transparency, ammonium and phosphates;and the third group of stations Kolokondé 2, Kpébouko1, Kpébouko 2 and Affon marked by high values of conductivity, TDS, transparency, depth and temperature. The canonical correspondence analysis revealed a strong positive correlation between Nemouridae and ammonium as well as between Perlidae, Taeniopterygidae, Ephemeridae, Heptageniidae, Isonychiidae, Elmidae and phosphate. This study is a crucial step for any management and monitoring of this river.展开更多
Leaf litter input from riparian landscapes has been identified as both a major energy flow to stream ecosystems and as a food source for stream macroinvertebrates. In this study the benthic macroinvertebrate community...Leaf litter input from riparian landscapes has been identified as both a major energy flow to stream ecosystems and as a food source for stream macroinvertebrates. In this study the benthic macroinvertebrate community was used to evaluate the decomposition of organic matter in river systems. The aim of this work was to study the decomposition of organic matter using the benthic macroinvertebrate colonization. The research was developed over five months (January 2011 to May 2011) in four different sites, distributed along the River Ferreira terminal area, northern Portugal. A litter bag experiment was used to examine the role of macroinvertebrate communities in the processing of organic material on the river. Litter bags were placed in the water and collected every 7, 15, 30, 60, 90 and 120 days. In litter bags was observed a high abundance of Oligochaeta and Chironomidae, which are characterized by being detritivorous-herbivores and filtering collectors, respectively, indicating the benthic macroinvertebrate more involved on the decomposition of organic matter. These results contributed to increase current knowledge about benthic macroinvertebrate communities and may serve as incentive for future research works.展开更多
文摘The diversity of Samoa’s freshwater macroinvertebrates remains largely unexplored, with past studies focusing on specific species without comprehensive cataloguing. This research evaluated the health of Upolu Island’s rural rivers through macroinvertebrate analysis, particularly in the Le Afe and Mulivaifagatoloa Rivers. Collaborating with Samoa’s Water Resources Division in the Ministry of Natural Resources and Environment (MNRE), three sites along each river were sampled, representing a gradient from pristine to anthropogenically impacted areas. A total of 2953 macroinvertebrates were collected and classified into five categories using established identification keys. The Macroinvertebrate Community Index (MCI) and Quantitative Macroinvertebrate Community Index (QMCI) were applied for analysis. The results showed no clear pattern of pollutant-sensitive species prevalence or decline in less disturbed rivers. High MCI scores with low QMCI values indicated numerous low-scoring species, while the opposite suggested a richness of high-scoring taxa. Although MCI and QMCI are tools for monitoring freshwater health, this study lays the groundwork for future research to categorize Samoan macroinvertebrates and assign tolerance scores based on their presence in varying river conditions. .
文摘Benthic macroinvertebrate communities in Spartina alterniflora zones in the Yangtze Estuary, in China, were investigated seasonally in 2005, and their structure and biodiversity were analyzed. Twenty-one species were identified, across four Classes; 10 species of Crustacea, five species of Polychaeta, five species of Gastropoda, and one species of Lamellibranchia. Dominant species included： Assiminea sp., Notomastus latericeus, Cerithidea largillierl, Gtauconome chinensi and Gammaridae sp. Functional groups were comprised of a phytophagous group and a detritivorous group. The average density of all benthic macroinvertebrates was 650.5 ±719.2 inds/m^2 in the survey area. The high value of the standard deviation of the average density was a result of abundant Assiminea sp. at Beihu tidal flats. The average density of macroinvertebrates from Beihu tidal flat, Chongming Dongtan to Jinshanwei tidal flat decreased gradually. There was significant difference between compositions and abundance of macroinvertebrates along the estuary gradient （P 〈 0.05）. The density and biodiversity were highest in summer and lowest in winter. The mean biomass of macroinvertebrates was 20.8 ± 6.1 g/m^2. Biomass changed seasonally in the same way as density, with the change in biomass being： summer （Aug.） 〉autumn （Oct.） 〉spring （Apr.） 〉 winter （Dec.）. A BIO-ENV analysis showed that the mean grain size of sediment, height of Spartina and salinity were the ma- jor factors which affected the structure of the macroinvertebrate community. Variations in the community structure were probably caused by the population dynamics of S. alterniflora along with the variation in sampling time and location.
基金National Natural Science Foundation of China, No.51209010 No.41001008+2 种基金 International Science ＆ Technology Cooperation Program of China, No.2011DFA20820 2011DFG93160 Fund from Tsinghua University, No.20121080027
文摘This study presents findings of the first systematic analysis of aquatic biotic assemblages in the source region of the Yellow and Yangtze Rivers. It provides an initial basis with which to select representative organisms as indicators to assess the aquatic ecological status of rivers in this region. Macroinvertebrates are considered to be good indicators of long-term environmental changes due to their restricted range and persistence over time. Field investigations of macroinvertebrates were conducted in August 2009 in the source region of the Yellow River, and in July 2010 in the source region of the Yangtze River. Altogether 68 taxa of macroinvertebrates belonging to 29 families and 59 genera were identified. Among them were 8 annelids, 5 mollusks, 54 arthropods and 1 other animal. In the source region of the Yellow River, taxa number, density and biomass of macroinvertebrates were 50, 329 individuals m2 and 0.3966 g dry weight m2, respectively. Equivalent figures for the source region of the Yangtze River were 29, 59 individuals m2 and 0.0307 g dry weight m-2. The lower benthic animal resources in the source region of the Yangtze River are ascribed to higher altitude, higher sediment concentration and wetland degradation. Preliminary findings of this exploratory study indicate that hydroelectric power stations had a weak impact on benthic dwellers but wetland degradation caused by a series of human activities had a catastrophic impact on survival of macroinvertebrates. Ecological protection measures such as conservative grazing and vegetation management are required to minimize grassland degradation and desertification, and reduce soil erosion rate and river sediment discharge.
文摘The focus of this study was to investigate the macroinvertebrate community in surface mine wetlands. Nine wetlands were sampled for macroinvertebrates from July 1993 through May 1994.These sites represented a range of physical,chemical, and biological parameters. Macroinvertebrates were found in all sites;a total of 14 orders, 40 families,and 70 genera were identified in the samples. Insects were the most common invertebrates,and most functional feeding groups were represented. Predators dominated with 63% of the taxa, followed by the collector/gathers with 20%,shredders 14%, and scrapers 3%. Sites differed in the number of taxa inhabiting them.Richness ranged from 10 genera to 52.The lowest richness was found in two seasonal wetlands that were dry for the majority of the year. A permanently flooded site with no water quality problems and a dense growth of aquatic plants had the highest richness.
基金Supported by the National Natural Science Foundation of China(Nos.31400469,41571495,31770460)the National Science and Technology Basic Research Program(No.2015FY110400-4)+2 种基金the China Three Gorges Corporation Research Project(No.JGJ/0272015)the Key Program of the Chinese Academy of Sciences(Comprehensive Assessment Technology of River Ecology and Environment for the Water Source Region of "South-toNorth Water Diversion Central Route")the Program for Biodiversity Protection(No.2017HB2096001006)
文摘As a less time-consuming procedure, subsampling technology has been widely used in biological monitoring and assessment programs. It is clear that subsampling counts af fect the value of traditional biodiversity indices, but its ef fect on taxonomic distinctness(TD) indices is less well studied. Here, we examined the responses of traditional(species richness, Shannon-Wiener diversity) and TD(average taxonomic distinctness: Δ +, and variation in taxonomic distinctness: Λ +) indices to subsample counts using a random subsampling procedure from 50 to 400 individuals, based on macroinvertebrate datasets from three dif ferent river systems in China. At regional scale, taxa richness asymptotically increased with ?xed-count size; ≥250–300 individuals to express 95% information of the raw data. In contrast, TD indices were less sensitive to the subsampling procedure. At local scale, TD indices were more stable and had less deviation than species richness and Shannon-Wiener index, even at low subsample counts, with ≥100 individuals needed to estimate 95% of the information of the actual Δ + and Λ + in the three river basins. We also found that abundance had a certain ef fect on diversity indices during the subsampling procedure, with dif ferent subsampling counts for species richness and TD indices varying by regions. Therefore, we suggest that TD indices are suitable for biodiversity assessment and environment monitoring. Meanwhile, pilot analyses are necessary when to determine the appropriate subsample counts for bioassessment in a new region or habitat type.
文摘The Nokoue Lake is the largest lake of Benin Republic and it is also considered as one of the most productive lagoon ecosystems in West Africa. This productivity is decreasing and thus raises productivity issue for a better management and conservation. Macroinvertebrate can be useful for this purpose. A study was conducted to assess the spatial variation of macroinvertebrates during high flood period. A total of 3892 macroinvertebrates of fresh and brackish water were sampled during the survey. Structural analysis of the macroinvertebrate community revealed that it was made up of 16 orders, 48 families and 66 genera dominated by Insecta compared to Mollusca, Crustacea and the Annelida. Insects were dominated by Diptera (Chironomus sp. and Tanytarsus sp.), Coleoptera (Dystiscidae) and accounted for 57.1% of the sampled population. Mollusca, Crustacea, Annelida and Arachnida were the following most abundant and represented 23.9%, 10.7%, 8.1% and 0.2% of the total population, respectively. The Evenness index of Pielou was higher on the Station 8 (0.91 - 0.97), close to Oueme River. However, no significant difference (p > 0.05) was observed neither between station nor between month on the Shannon-Wiener index (2.06 - 4.31), Simpson index (0.04 - 0.40) and the taxa number (10 - 27). Macroinvertebrate assemblages and composition were primarily due to changes in water quality dependent on hydroclimatic changes and probably to anthropogenic actions. This suggests the need for real investigation of the macroinvertebrate biological capacity when formulating conservation strategies for the Nokoue Lake.
基金Supported by the Environmental Protection Department of China(No.PM-ZX019-201207-018)the National Natural Science Foundation of China(No.31100407)。
文摘Estimating recovery times from pollution incident is an important issue of targeted biomonitoring programs.In the present study,the impact and recovery of macroinvertebrate communities from a cadmium wastewater discharge in the Longjiang River,Guangxi,China,in early January 2012 were studied based on 83 samples collected in fi ve surveys within 20 months after the incident.The pollution aff ected seriously the local aquatic biota,and consequently,the invertebrate abundance and species richness were reduced considerably.Twelve months later,the taxonomic number of macroinvertebrates began to increase.However,sensitive taxa remained rare.Twenty months later,the taxon richness and abundance of macroinvertebrates increased signifi cantly compared to those in the previous four time points.To explore the possible time-scale over which pre-disturbance conditions might occur,we chose four diff erent typical metrics of taxa richness(total taxa number,cumulative taxa number,taxa number per samples,and the Shannon-Wiener diversity index)and extrapolated modeled recovery trajectories.Target values for the four metrics were set at average values for sites from the nearby Lijiang River,which were used as a reference.Assuming a continued linear trajectory,the recovery times were estimated to be 52,39,39,and 31 months,respectively,which was roughly 3-5 years.This is consistent with results from recovery times from other studies of acute pollution cases,but contrasted strongly to the much longer recovery times associated with chronic pollution from groundwater contamination and mine-tailing runoff.
文摘In this study conducted in the coastal zone of Cameroon, biological indices and functional feeding groups of benthic macroinvertebrates were used to assess the health status of two urban streams. For a better diagnosis, two streams located in coastal forest zone were used as a reference. Benthic macroinvertebrates were sampled monthly over a 3-month period (from May to July 2017) in six urban stations and six forest stations. Measurements of the physicochemical variables were done simultaneously. Physicochemical analysis revealed that urban streams are strongly polluted with high content of decaying organic matters, while forest streams are slightly polluted as indicated by the Principal Component Analysis. Concerning benthic macroinvertebrates, urban streams are poorly diversified with the proliferation of taxa tolerant to water pollution and belonging to the functional feeding groups of collectors-gatherers. Inversely, forest streams are more diversified and dominated by sensitive taxa, most belonging to the functional feeding groups of predators and shredders. These marked differences between biological indices and feeding mode of benthic macroinvertebrates in forest and urban rivers confirm the reliability of benthic macroinvertebrates as good indicators of freshwater ecosystem in the coastal zone of Cameroon.
文摘Reed pans are a very uncommon type of endorheic wetland, and as such the amount of information available is very limited. Thus, they are being impacted on by various agricultural, livestock and other anthropogenic activities. The objectives of this study were to determine the spatial and temporal variations of macroinvertebrate community structures in reed pans and the environmental factors (i.e., water quality) responsible for the maintenance of these structures. Reed pans were studied over four different seasons, during which time subsurface water, sediment and macroinvertebrate samples were collected and analyzed. The reed pans studied showed that the macroinvertebrates were able to reflect various changes in reed pans with regard to seasonal variability and anthropogenic impacts on water quality. These anthropogenic impacts caused the disappearance of sensitive macroinvertebrate taxa and the increase of tolerant macroinvertebrate taxa.
文摘Taudaha Lake is one of the important wetlands in Nepal, as it provides critical habitats for thousands of migratory birds and fishes. Despite being a critically important water body, there is a lack of detail chemical and biological studies on this lake. The present study investigates the effects of seasonal water quality variations in distribution and abundance of macroinvertebrates in Taudaha Lake, during four different seasons in 2006. The results indicate that all the water quality parameters, except secchi depth, and total alkalinity, significantly varied among seasons. The gross primary productivity of the lake also significantly varied among the seasons, with highest primary production during summer (3.92 ± 0.18 gC/m<sup>3</sup>/day) and lowest during spring (2.44 ± 0.67 gC/m<sup>3</sup>/day). A total of 2166 individual benthic macroinvertebrates from 10 families and 7 orders were collected during the study period. Unlike water quality parameters, the macroinvertebrate species composition did not vary significantly among the seasons. The results suggested that the change in lake water quality did not have significant impacts on community metrics such as species diversity, species richness, and species evenness.
文摘The impact of land use changes on watercourses is poorly documented in Cameroon. Therefore, this study examines the effects of agriculture and urbanization on water quality, the structure and functional organization of macroinvertebrates of streams in the coastal zone of Cameroon. Nine sampling stations including three per catchment area with different land occupations (agricultural, urban and forest) were selected. Benthic macroinvertebrates were sampled monthly from February to July 2018 and the physicochemical variables were measured simultaneously. The urban and agricultural streams showed highly polluted waters with high nutrient and suspended matter content, whereas the forest stream waters are moderately polluted. In addition, the hierarchical ascending classification indicated a proximity in water quality between the agricultural and forest streams for which the main physicochemical variables did not vary significantly. With regards to macroinvertebrates, the forest watercourse is characterized by the proliferation of pollution-sensitive taxa, high diversity indices and complex trophic structuring, indicating its good ecological status. In contrast the urban watercourse, heavily polluted is characterized by low diversity indices reflecting a simplification of the structure of stands dominated by the pollution-tolerant collector-gatherer stands. The majority of biological indices and functional feeding groups were not significantly different between the agricultural and forest streams, suggesting a less pronounced impact of agriculture on macroinvertebrates. Our results showed that, riparian vegetation even though constituted of perennial crops, reduces the effects of agricultural inputs on streams and promotes the establishment of diversified macroinvertebrate communities.
文摘The area of the city of Meknes (Morocco) undergoes anthropic pressure, which acts mainly on the rivers. River water is used, without preliminary treatment, for farm irrigation. A study of the impacts of anthropogenic activities on the distribution and biodiversity of benthic macroinvertebrates and water quality of the Boufekrane River (Meknes) was conducted. Four pristine stations from the upstream and two stations at the downstream receiving anthropogenic impacts were selected along the River. For 12 consecutive months (from January to December 2010), based on the SEQ-V.2 scoring system, water quality index classes, the upstream stations recorded significantly higher biological monitoring scores and better water quality indices than those of the downstream. Four variables are involved actively in the individualization of the physico-chemical environment: COD, dissolved oxygen, TSS and temperature. The total number of macrobenthic taxa and their overall richness indices and diversity indices were significantly higher at the upstream stations than at the downstream stations. The relationships between the physicochemical and the macrobenthic data were investigated by biotypology analysis (PCA and FCA) and Pearson correlation analysis. The analyses showed that the richness and diversity indices were generally influenced by the total suspended solids, chemical oxygen demand and the electric conductivity of the river water. This study also highlighted the impacts of anthropogenic activities on the distribution and species diversity of macrobenthic invertebrate. Some sensitive (Trichoptera and Ephemeroptera) and resistant species (Oligochaeta such as Tubifex sp.) are identified as potential bioindicators of clean and polluted river ecosystems, respectively, in Morocco rivers. The data obtained in this study supported the use of the bioindicator concept (Innovative Biotechniques for controlling water quality) for North Africa rivers because it is more efficient than conventional methods.
文摘The influence of water quality on the variation patters of benthic macroin-vertebrate communities in the lakes in the central highlands of Peru was eva-luated. Samples of water and sediments were collected in 23 different sam-pling sites last 2017. The physiochemical variables of water quality deter-mined on site were: DO, TDS, EC, temperature and pH. The results obtained revealed that the physiochemical indicators are within the environmental quality standards for water, except COD and BOD5. Regarding the benthic macroinvertebrates, four phyla were identified wherein the most common is the phylum Arthropoda having the abundance and richness of taxa. The PCA reduced the variables to a few significant components that caused variation in water quality between lakes. The cluster analysis in relation to the relative abundance of benthic macroinvertibrates grouped the 22 sampling sites into three groups with the similar characteristics. The PCoA analysis of the ben-thic macroinvertebrate communities showed a clear separation of sites. The SIMPER analysis at the family-level showed the distribution of the most common species. Therefore, at a significance level of 0.01 it demonstrates that there are significant differences between the number of species and abun-dance of the areas that were evaluated.
文摘Marsh flooding and drying may be important factors affecting aquatic macroinvertebrate density and distribution in coastal freshwater marshes. Limited availability of water as a result of drying in emergent marsh may decrease density, taxonomic diversity, and taxa richness. The principal objectives of this study are to characterize the seasonal aquatic macroinvertebrate assemblage in a freshwater emergent marsh and compare aquatic macroinvertebrate species composition, density, and taxonomic diversity to that of freshwater marsh ponds. We hypothesize that 1) freshwater emergent marsh has lower seasonal density and taxonomic diversity compared to that of freshwater marsh ponds;and 2) freshwater emergent marsh has lower taxa richness than freshwater marsh ponds. Seasonal aquatic macroinvertebrate density in freshwater emergent marsh ranged from 0 organisms/m2 (summer 2009) to 91.1 ± 20.53 organisms/m2 (mean ± SE;spring 2009). Density in spring was higher than in all other seasons. Taxonomic diversity did not differ and there were no unique species in the freshwater emergent marsh. Our data only partially support our first hypothesis as aquatic macroinvertebrate density and taxonomic diversity between freshwater emergent marsh and ponds did not differ in spring, fall, and winter but ponds supported higher macroinvertebrate densities than freshwater emergent marsh during summer. However, our data did not support our second hypothesis as taxa richness between freshwater emergent marsh and ponds did not statistically differ.
文摘The Blue River Main wastewater treatment facility (WWTF) discharges into the upper Blue River (725 km2), and is recently upgraded to implement biological nutrient removal. We measured biotic condition upstream and downstream of the discharge utilizing the macroinvertebrate protocol developed for Kansas streams. We examined responses of 34 metrics to determine the best indicators for discriminating site differences and for predicting biological condition. Significant differences between sites upstream and downstream of the discharge were identified for 15 metrics in April and 12 metrics in August. Upstream biotic condition scores were significantly greater than scores at both downstream sites in April (p = 0.02), and in August the most downstream site was classified as non-biologically supporting. Thirteen EPT taxa (Ephemeroptera, Plecoptera, Trichoptera) considered intolerant of degraded stream quality were absent at one or both downstream sites. Increases in tolerance metrics and filtering macroinvertebrates, and a decline in ratio of scrapers to filterers all indicated effects of increased nutrient enrichment. Stepwise regressions identified several significant models containing a suite of metrics with low redundancy (R2 = 0.90 - 0.99). Based on the rapid decline in biological condition downstream of the discharge, the level of nutrient removal resulting from the facility upgrade (10% - 20%) was not enough to mitigate negative effects on macroinvertebrate communities.
文摘The unique challenges associated with sampling of macroinvertebrates in flashy urban streams create a methods gap. These streams form isolated pools for much of the year, interspersed with spates that scour and deposit excessive amounts of sediment. Commonly used stream grab sampling methods, such as nets and Hess and Surber fixed-area samplers, work well in wadable streams with perennial flow. Deployed samplers (Hester-Dendy, gravel tray) can be used in waters with or without flow. We evaluated three methods which don’t require stream flow: modified Hester-Dendy (MHD), gravel tray, and bucket (a type of cylinder grab sample method), for their potential use in bioassessment of a project involving daylighting of a 180-m culvert on Congress Run, a flashy urban tributary to Mill Creek in Cincinnati, Ohio. Method efficacy was measured using three criteria: usability (level of effort and recoverability of samplers), variability, and community retrieval completeness. The bucket method required the lowest level of effort and had the highest sample recovery. The bucket sampler had the lowest variability for most metrics, including the critical metric of taxa richness, with a coefficient of variation (CV) of 20.9%. The MHD and tray samplers had taxa richness CVs of 42.9% and 53.9%, respectively. The bucket sampler also had the lowest CV (27.4%) for a multi-metric index. The bucket sampler performed best with respect to community retrieval completeness, with higher pooled and average taxa richness. The total number of taxa collected from all the replicate bucket grab samples (42) was greater than that collected by the HD and tray samplers combined (27). Multivariate analyses showed significant grouping with respect to methods and location. This study supports the bucket grab sampler method as a candidate for sampling of flashy urban streams.
文摘Outdoor education programs frequently offer stream classes that teach students how to assess water quality based on the composition of aquatic macroinvertebrate communities. Repeatedly using the same site for stream classes can cause disturbance that could negatively impact aquatic macroinvertebrates. However, the impact of outdoor education stream classes on short term temporal trends of aquatic macroinvertebrates has not been evaluated. Our objective was to quantify whether outdoor education stream classes caused localized and short-term impacts on the aquatic macroinvertebrate community. We sampled aquatic macroinvertebrates over a five day period in May 2014 from an impacted riffle subjected to repeated substrate disturbance by outdoor education stream classes and an unimpacted riffle that was not subjected to stream classes within an agricultural stream in central Ohio. We did not observe a difference in macroinvertebrate community response variables between different time periods or among days within the impacted riffle as part of our within riffle analysis. We documented that macroinvertebrate abundance and dorsoventrally flattened clinger abundance was greater within the unimpacted riffle than the impacted riffle. Macroinvertebrate evenness was greater in the impacted riffle than the unimpacted riffle. In the impacted riffle percent clingers was greater on Monday than on Friday. Conversely, in the unimpacted riffle percent clingers was greater on Friday than on Monday. Our results indicated that outdoor education stream classes did not alter short term temporal trends of macroinvertebrate community structure within an impacted riffle, but the stream classes resulted in differences in community structure between an impacted and unimpacted riffle. Our results suggest that outdoor education centers should avoid repeatedly using the same site for their stream classes to prevent negatively impacting aquatic macroinvertebrates.
文摘Investigations on biological capacity of water quality of macroinvertebrate community are very uncommon, and such as the amount of information available on the Nokoue Lake (the largest lake of Benin) is very limited. This information gap needs to be filled for better management of the Nokoue Lake. The goal of this study was to evaluate the possibility of using the macroinvertebrate community structures in Nokoue Lake and the environmental factors responsible for the maintenance of these structures. Nokoue Lake was studied over three months, during high flood period in which time subsurface water and macroinvertebrate samples were collected and analyzed. A study showed that the macroinvertebrate assemblages was done according to ecological gradients as pH, conductivity, TDS, salinity, chlorophyll a and probably to anthropogenic actions (nutriments). Better than the percentage of insects, the percentage of Chironomidae informed very well about macroinvertebrate assemblages. To assess the biological health of the environment, the Family Biotic Index (FBI) turns out to be more appropriate than diversity indices that do not take into account the intermediate pollution. Organic pollution revealed by the FBI probably affects the aquatic life.
文摘The Affon River is one of the important rivers of the Ouémé River whose benthic diversity remained unknown. The present study aims to make the relationship between macroinvertebrates and physico-chemical parameters to access water quality of the Affon River. The measurement of physico-chemical parameters (temperature, pH, conductivity, transparency, depth and TDS, dissolved oxygen, ammonium, nitrite and phosphate) and the sampling of macroinvertebrates using a Surber net were carried out during floods in eight stations. A principal component analysis (PCA) and canonical correspondence analysis (CCA) were used. The indices of Shannon, Piélou, Simpson, Hilsenhoff, EPT and EPT/Chironomidae were used to assess the level of water pollution. The study identified 9755 macroinvertebrates divided into 4 classes, 14 orders and 49 families. Pollution-sensitive families (14 families) that are organic pollution indicators, as well as pollution-tolerant families (Chironomidae, Limnaeidae, Bithynidae, Physidae) were captured. Chironomidae were the most predominant and abundant family (FO = 100%). The predominance of Chironomidae coupled with the rarity of the Ephemeroptera, Trichoptera and Plecoptera would reflect the poor quality of the Affon River waters. The principal components analysis yielded groups of associations: The first group of stations Taneka 2 and 3 characterized by high values of ammonium and phosphate;and low values of conductivity and TDS;the second group of Tanéka 1 and Kolokondé 1 stations with low values of pH, transparency, ammonium and phosphates;and the third group of stations Kolokondé 2, Kpébouko1, Kpébouko 2 and Affon marked by high values of conductivity, TDS, transparency, depth and temperature. The canonical correspondence analysis revealed a strong positive correlation between Nemouridae and ammonium as well as between Perlidae, Taeniopterygidae, Ephemeridae, Heptageniidae, Isonychiidae, Elmidae and phosphate. This study is a crucial step for any management and monitoring of this river.
文摘Leaf litter input from riparian landscapes has been identified as both a major energy flow to stream ecosystems and as a food source for stream macroinvertebrates. In this study the benthic macroinvertebrate community was used to evaluate the decomposition of organic matter in river systems. The aim of this work was to study the decomposition of organic matter using the benthic macroinvertebrate colonization. The research was developed over five months (January 2011 to May 2011) in four different sites, distributed along the River Ferreira terminal area, northern Portugal. A litter bag experiment was used to examine the role of macroinvertebrate communities in the processing of organic material on the river. Litter bags were placed in the water and collected every 7, 15, 30, 60, 90 and 120 days. In litter bags was observed a high abundance of Oligochaeta and Chironomidae, which are characterized by being detritivorous-herbivores and filtering collectors, respectively, indicating the benthic macroinvertebrate more involved on the decomposition of organic matter. These results contributed to increase current knowledge about benthic macroinvertebrate communities and may serve as incentive for future research works.
