Biological Assessment Of Water Quality Research Articles

Physicochemical and Biological Water Quality Assessment of Local Ponds of Tumakuru, Karnataka, India

Water is an essential component of life. The developments, urbanization and load of the various pollutant sources lead to the deterioration of the ponds. Therefore, the study was conducted to assess the physicochemical and biological characteristics of water from the regional ponds of Tumakuru, Karnataka, India. The water samples from six ponds were taken for the study. The physicochemical parameters showed that the pH of the ponds was found to be 7.35, 6.90, 7.21, 7.91, 7.16 and 8.10, respectively. EC was found to be 0.60, 0.19, 0.42, 0.22, 1.43 and 1.0, respectively. The high value of pH and EC shows its nutrient-rich and alkaline nature. Cl was found to be 4.0, 3.0, 4.4, 2.6, 2.4 and 6.8, respectively. Calcium hardness was observed as 1.9, 2.58, 2.34, 1.15, 1.11 and 12.19, respectively. The Biological oxygen demand (BOD) of the samples was found to be 0.1, 1.6, 0.8, 3.3, 1.2 and 0.4 mg/lit, respectively. Qualitative analysis through most probable number (MPN) method was employed. MPN index of water samples which tested satisfactory was < 2 per 100 mL and MPN index of water sample no. WS1, WS3 and WS5 respectively whereas unsatisfactory ranged from 38 to > 1600 per 100 mL of water sample no. WS2, WS4 and WS6, respectively showed that the water was not suitable for domestic uses having s high value of bacterial load. In order to stop the spread of intestinal illnesses, drinking water sources should undergo routine assessment of physicochemical and microbiological quality tests.

The effect of water temperature changes on biological water quality assessment

Increasing temperatures caused by anthropogenic climate change are leading to changes in the composition of local communities across biomes. This has implications for ecological assessment methods that rely on macroinvertebrates as bioindicators of water quality. To investigate the influence of changing water temperature on these assessment methods, we analysed macroinvertebrate data from Swiss national monitoring programs. We used a species distribution model to simulate temperature change effects on macroinvertebrate communities and estimated the resulting changes on three biological indices commonly used in Switzerland, namely the species richness of Ephemeroptera, Plecoptera and Trichoptera (EPT), the Swiss biological (IBCH) index along with its components, as well as the species at risk pesticides (SPEARpesticides) index. While results vary by temperature scenario and index, our model results for the most realistic water temperature increase scenario of + 2 °C across most sites in Switzerland suggest no, or only a minor, influence of temperature (not accounting for other hydrological changes). Our model projection predicted only a small increase in the probability of occurrence for 70 % of the studied families. The sensitivity to temperature as captured in our model is generally not very high and varies among the biological indices: on average across all sites, a + 2 °C increase in temperature resulted in a 7 % increase in EPT species richness, a 4 % increase in the IBCH index, and a less than 1 % increase in the SPEARpesticides index. Our study suggests the robustness of these biological indices to moderate warming and points towards the usefulness of these biological indices for the next few decades as tools for water quality assessment. Despite some limitations of statistical species distribution models (e.g., not accounting for dispersal limitation or biotic interactions, predictive performance varying by taxon), the study provides valuable insights into the complex relationships between environmental factors and macroinvertebrate communities, and the potential impacts of future temperature change. These findings can inform conservation and management efforts for these important ecological systems.

Impact of nutrients and trace elements on freshwater microbial communities in Croatia: identifying bacterial bioindicator taxa.

Since aquatic microbial communities promptly respond to environmental changes, it is now evident that they can complement traditional taxa such as fish, macroinvertebrates and algae as bioindicators of water quality. The aim of this study was to correlate the physico-chemical parameters of water with the microbial community structure and the occurrence of putative bioindicator taxa. Thirty-five water samples were collected throughout Croatia and their physico-chemical parameters, including the concentration of trace elements using the high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS), and the composition of the microbial communities by high-throughput sequencing of the 16S rRNA marker gene, were analysed in parallel. Partial least squares regression (PLS-R) modelling revealed that a number of microbial taxa were positively correlated with some of the water parameters. For example, some taxa from the phylum Proteobacteria were positively correlated with the ion content of the water (e.g. Erythrobacter, Rhodobacteraceae, Alteromonadaceae), while some Firmicutes taxa, such as the well-known faecal indicators Enterococcus and Clostridium, were correlated with nutrient content (ammonium and total phosphorus). Among the trace elements, uranium was positively correlated with a highest number of microbial taxa. The results obtained will aid in development of protocols for eDNA-based biological assessment of water quality.

Taxonomic Diversity and Biological Water Quality Assessment of Rivers Bhagirathi and Yamuna at Gangotri and Yamunotri Using Benthic Macroinvertebrates

Taxonomic Diversity and Biological Water Quality Assessment of Rivers Bhagirathi and Yamuna at Gangotri and Yamunotri Using Benthic Macroinvertebrates

Ecological characterisation of urban ponds in the Netherlands: a study based on data collected by volunteers

Blue space in the urban environment can positively contribute to public health and well-being. Many urban freshwater systems, however, are exposed to anthropogenic stressors, resulting in deteriorated water quality and biodiversity. Private garden ponds are essential elements of this blue space but little is known about their water quality since they are not monitored by water professionals. The Dutch citizen science initiative Waterdiertjes.nl focusses on biological water quality assessment using macroinvertebrates and launched a campaign to investigate garden ponds in 2021. The campaign yielded macroinvertebrate recordings in 60 garden ponds and limited additional information on dimensions, and presence of water vegetation and fish. Volunteers also investigated 92 public urban ponds in 2021. Combining both data allowed for evaluation of the similarity between both pond types. Analyses were also performed to discover the importance of pond dimensions and presence of aquatic vegetation or fish for the macroinvertebrate biodiversity and water quality. Multivariate analyses showed a considerable overlap in macroinvertebrate community composition between garden and public urban ponds. Results showed high variability in taxon richness, total macroinvertebrate density and water quality scores A significant, nonlinear relation was observed between pond depth and macroinvertebrate taxon richness with the highest richness at a depth of 0.5-1m. Submerged vegetation correlated significantly with taxon richness with little vegetation having the lowest richness. Presence of fish or floating vegetation was not significantly related to taxon richness, total density and water quality scores possibly due to unnatural conditions that underlie in garden ponds. Since water professionals and academic scientists do not monitor garden ponds, citizen science may provide valuable data on water quality and biodiversity in these waters. The present initiative showed that volunteers can successfully monitor understudied ecosystems and gather data on temporal and spatial scales complementary to professional data that lead to new (ecological) insights.

Evaluation of benthic macroinvertebrate communities in upstream and downstream of Kulekhani Multipurpose Reservoir, Makawanpur, Nepal

Reservoir construction in the natural waterways can disrupt the structure and function of riparian ecosystems with the alteration in abundance and composition of aquatic organisms. This study assessed the variation in Benthic Macroinvertebrates (BMIs) communities in upstream (Chitlang and Seti Streams) and downstream (spillway) of Kulekhani multipurpose reservoir, Makawanpur, Nepal. Multi-habitat qualitative samplings with Ganga River System Biotic Score (GRSBIOS) index was used for the biological water quality assessment. Out of total 25 families and 8 orders of identified BMIs, Diptera and Coleoptera order are abundant whereas Oligochaeta and Odonata order are lowest. Taxa richness and abundance of BMIs were estimated to be higher upstream. Number of EPT taxa (6 to 2) and percentage of EPT (35.07 to 28.04 %) abundance were recorded in decreasing order of response toward downstream. The upstream showed a high Shannon and Simpson’s diversity index. Chitlang Stream is found slightly polluted as Average Score Per Taxa (ASPT) score is calculated as 6.1 (River Water Quality Status (RWQS)-I)). Similarly, immediate downstream is critically polluted with RWQS-III whereas Seti Stream and spillway after 4 km were found to be moderately polluted as RWQS-II. Canonical Correspondence Analysis (CCA) showed that pH, temperature, and dissolved oxygen have a high influence in BMIs assemblages. The study depicts the ecological health of the stream immediately downstream of the reservoir is disturbed with presence of tolerant BMIs assemblages. The implication of the study can be in the assessment of impact caused by the reservoir in the ecological status of the water transfer.

Comparative environmental RNA and DNA metabarcoding analysis of river algae and arthropods for ecological surveys and water quality assessment

Environmental DNA (eDNA) metabarcoding is widely used for species analysis, while the use of environmental RNA (eRNA) metabarcoding is more limited. We conducted comparative eDNA/eRNA metabarcoding of the algae and arthropods (aquatic insects) in water samples from Naka River, Japan, to evaluate their potential for biological monitoring and water quality assessment. Both methods detected various algae and arthropod species; however, their compositions were remarkably different from those in traditional field surveys (TFSs), indicating low sensitivity. For algae, the species composition derived from eDNA and eRNA metabarcoding was equivalent. While TFSs focus on attached algae, metabarcoding analysis theoretically detects both planktonic and attached algae. A recently expanded genomic database for aquatic insects significantly contributed to the sensitivity and positive predictivity for arthropods. While the sensitivity of eRNA was lower than that of eDNA, the positive predictivity of eRNA was higher. The eRNA of terrestrial arthropods indicated extremely high or low read numbers when compared with eDNA, suggesting that eRNA could be an effective indicator of false positives. Arthropod and algae eDNA/eRNA metabarcoding analysis enabled water quality estimates from TFSs. The eRNA of algae and arthropods could thus be used to evaluate biodiversity and water quality and provide insights from ecological surveys.

Hydrogeochemical and biological assessment of spring and stream water quality for its suitability for drinking in Kanglung locality, Trashigang, Bhutan

Abstract Springs are important water sources for domestic and agricultural uses in eastern Himalayas. This study describes the water quality scenario and major geochemical processes of the springs utilized for drinking in Kanglung locality, Bhutan. Water samples were collected at two end-user taps and three spring sources from October 2020 through April 2021 for laboratory analyses. Water samples analyzed met the WHO drinking water quality standard except for turbidity and thermotolerant coliform in some samples. The Water Quality Index (WQI) values of the spring water ranged from 5.75 to 41.64, majority falling under excellent class demonstrating potability of springs tapped. The order of anion and cation chemistry were HCO3− >Cl− >SO42−, and Na+ >Ca2+>Mg2+>K+, respectively. The scatter diagrams and molar ratios of major ions indicated silicate and carbonate weathering controlling the spring water chemistry. The piper diagram indicated that springs are predominantly Ca-Mg-Cl and Na-Cl types. Gibbs diagrams inferred that spring/stream chemistry is mainly controlled by rainwater followed by water-rock interaction. Statistical analyses indicated different sources of dissolved ions including carbonate and silicate weathering, atmospheric precipitation, dissolution of sulphate minerals, and oxidation of sulphides.

Monitoring biological water quality by volunteers complements professional assessments.

Progressively more community initiatives have been undertaken over last decades to monitor water quality. Biological data collected by volunteers has been used for biodiversity and water quality studies. Despite the many citizen science projects collecting and using macroinvertebrates, the number of scientific peer-reviewed publications that use this data, remains limited. In 2018, a citizen science project on biological water quality assessment was launched in the Netherlands. In this project, volunteers collect macroinvertebrates from a nearby waterbody, identify and count the number of specimens, and register the catch through a web portal to instantaneously receive a water quality score based on their data. Water quality monitoring in the Netherlands is traditionally the field of professionals working at water authorities. Here, we compare the data from the citizen science project with the data gathered by professionals. We evaluate information regarding type and distribution of sampled waterbodies and sampling period, and compare general patterns in both datasets with respect to collected animals and calculated water quality scores. The results show that volunteers and professionals seldomly sample the same waterbody, that there is some overlap in sampling period, and that volunteers more frequently sampled urban waters and smaller waterbodies. The citizen science project is thus yielding data about understudied waters and this spatial and temporal complementarity is useful. The character and thoroughness of the assessments by volunteers and professionals are likely to differentiate. Volunteers collected significantly lower numbers of animals per sample and fewer animals from soft sediments like worms and more mobile individuals from the open water column such as boatsmen and beetles. Due to the lack of simultaneous observations at various locations by volunteers and professionals, a direct comparison of water quality scores is impossible. However, the obtained patterns from both datasets show that the water quality scores between volunteers and professionals are dissimilar for the different water types. To bridge these differences, new tools and processes need to be further developed to increase the value of monitoring biological water quality by volunteers for professionals.

MODEL FOR MANAGEMENT AND PLANNING OF FISHING PLAYFUL-SPORTS IN THE RIVER MOURO HYDROGRAPHIC BASIN

The Institute for the Conservation of Nature and Forests (ICNF) has recently carried out work on planning and management of recreational fishing in the area of ​​the Mouro River drainage basin — a mountain watercourse in the North of Portugal (River Hydrographic Basin). Minho) which is born near the place of Lagarto (Lamas de Mouro, Melgaço), in the Peneda-Gerês National Park (PNPG). The model adopted was initially implemented (2008) to manage that activity in the Olo river basin (BH of the Douro river), and this methodology also served as a foundation for creating in 2020 in the Northeast region of Trás-os-Montes (Mente rivers, Rabaçal and Tuela – Vinhais and Bragança) plus three recreational fishing areas. In this context, 13 sampling stations were set up (12 in the Mouro river and 1 in the Sucrasto river), considered representative of a large part of the habitats that make up this study area, where actions were carried out to monitor the ichthyofauna (electrical fishing) and hydromorphological characterization of habitats (River Habitat Survey, RHS). The monitoring of benthic macroinvertebrates was an additional action, recently introduced in this type of work, aimed at improving the biological assessment of water quality and aquatic ecosystems and which is serving as a basis for the preparation of a Master's Thesis. With this study, data was analyzed concerning age, growth, physical condition of the monitored specimens, as well as their relationship with the different types of habitats where they were captured. To detect spatial distribution patterns underlying biotic (species/abundance and species/ages) and environmental data, multivariate methods can be used. As a result of this work, the Ludic Fishing Zone (ZPL) of the Mouro River (and its tributaries) will be created, with the aim of promoting recreational and sport fishing based on more conservationist principles. With this initiative, ICNF intends to guarantee greater protection and sustainability of endogenous aquaculture resources, with particular emphasis on the case of Atlantic salmon (Salmo salar). This salmonid annually elects a significant part of these continental waters to complete its reproductive phase. However, other studies, in this context, should be developed to better understand the ecology of the species in a country that coincides with its southern limit of distribution in Europe.

Effects of floods on macroinvertebrate communities in the Zarin Gol River of\xa0northern Iran: implications for water quality monitoring and biological assessment

BackgroundThe timing, magnitude, and duration of extreme hydrological disasters have the potential to threaten the species diversity and river habitats. On August 8, 2014, and August 19, 2017, disastrous floods struck mountainous regions of Iran’s Zarin Gol River basin. Macroinvertebrate communities were studied at seven upstreams prior to the floods in June 2014 and 2017 and after the floods in September 2014 and 2017 and 9 months after the second flood in June 2018. The effects of floods on macroinvertebrate communities, recovery rate of macroinvertebrate community resilience and influencing factors were investigated.ResultsDespite the fact that extreme floods were the only reason of the disruption, the effects of biological water quality assessment metrics after the disaster were comparable to those of heavily polluted waters. Biological indicators revealed that the communities were unaffected prior to the floods, and the water quality remained within acceptable limits. Following the disasters, the density of macroinvertebrates declined, and biological indicators demonstrated the severe depletion of water quality. Community indicators (species richness, percent model affinity (PMA), and Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness) rebounded after 9 months (June 2018), demonstrating that Zarin Gol River’s macroinvertebrate communities could recover even after the severe impact of the floods. As a result, macroinvertebrate samples taken from flood-affected areas revealed that extreme flooding, rather than a decrease in water quality, causes a loss of diversity and abundance.ConclusionBecause of shifts in hydrological regimes in streams around the world, understanding the short-term impacts of strong flooding and the comparatively quick recovery of macroinvertebrate ecosystems has important consequences for bio-assessment programs after severe floods.

Species composition and distribution of mayflies (Ephemeroptera) in relation to land use systems along the Thika River, Kenya

Mayflies (order Ephemeroptera) are widely distributed and commonly used in biological assessment of water quality because of their sensitivity. Their application as bio-indicators in tropical streams and rivers, however, is hampered by lack of adequate information about their status in many such ecosystems. The current study investigated their species composition, distribution and abundance in relation to land use and water quality characteristics of the Thika River, Kenya. The Thika River emanates from the Aberdare Ridges and flows through forest, agricultural and urban catchments. Sampling was carried out at three sites representing forest, agricultural and urban land use systems. Dissolved oxygen, conductivity, total dissolved solids, temperature and transparency were measured in situ at each sampling station. Macroinvertebrates were sampled using a modified Hess sampler and the Ephemeropterans were later identified and sorted in the laboratory. Thirteen Ephemeroptera genera belonging to six families were obtained. Mean larvae abundance was 1 238 ind. m−2. Acanthiops (70.4%) and Afronurus (13.3%) dominated the community at all sites. The current study revealed that decreasing Ephemeroptera taxa abundance along the river channel indicates decreasing water quality.

Indicators of summer phytoplankton development of the Tsna River in the biological quality control of water

The analysis of the species and taxonomic diversity of summers phytoplankton was carried out for river Tsna of the Tambov region. Methods of biological assessment of water quality in determining the degree of saprobity of water bodies are considered.

Physico-Chemical and Biological Assessment of Water Quality in Shihu Lake and Grand Canal, P.R. China

Physico-Chemical and Biological Assessment of Water Quality in Shihu Lake and Grand Canal, P.R. China

Using native and invasive livebearing fishes (Poeciliidae, Teleostei) for the integrated biological assessment of pollution in urban streams

Invasive species are increasingly replacing native species, especially in anthropogenically transformed or polluted habitats. This opens the possibility to use invasive species as indicator taxa for the biological assessment of pollution. Integrated biological assessment, however, additionally relies on the application of multiple approaches to quantify physiological or cytogenetic responses to pollution within the same focal species. This is challenging when species are restricted to either polluted or unpolluted sites. Here, we make use of a small group of neotropical livebearing fishes (family Poeciliidae) for the integrated biological assessment of water quality. Comparing urban and suburban stream sections that receive varying degrees of pollution from industrial and domestic waste waters in and around the Brazilian city of Uberlândia, we demonstrate that two members of this family may indeed serve as indicators of water pollution levels. The native species Phalloceros caudimaculatus appears to be replaced by invasive guppies (Poecilia reticulata) at heavily polluted sites. Nevertheless, we demonstrate that both species could be used for the assessment of bioaccumulation of heavy metals (Pb, Cu, and Cr). Ambient (sediment) concentrations predicted concentrations in somatic tissue across species (R2-values between 0.74 and 0.96). Moreover, we used cytogenetic methods to provide an estimate of genotoxic effects of water pollution and found pollution levels (multiple variables, condensed into principal components) to predict the occurrence of nuclear abnormalities (e.g., frequencies of micro-nucleated cells) across species (R2 between 0.69 and 0.83). The occurrence of poeciliid fishes in urban and polluted environments renders this family a prime group of focal organisms for biological water quality monitoring and assessment. Both species could be used interchangeably to assess genotoxic effects of water pollution, which may facilitate future comparative analyses over extensive geographic scales, as members of the family Poeciliidae have become invasive in tropical and subtropical regions worldwide.

Resilience of benthic macroinvertebrates to extreme floods in a Catskill Mountain river, New York, USA: Implications for water quality monitoring and assessment

Abstract Changes in the timing, magnitude, frequency, and duration of extreme hydrologic events are becoming apparent and could disrupt species assemblages and stream ecosystems across the Northeastern United States. Between August 28 and 29 of 2011, an average of 31 cm of rain from Tropical Storm Irene fell across Eastern New York State in less than 24 h and caused historic flooding in numerous streams of the Catskill Mountain Region. Peak discharges exceeded the 0.01 annual exceedance probability (>100 year flood) in many Catskill Mountain streams. Approximately one week later, the remnants of Tropical Storm Lee deposited another 19 cm of rain onto saturated soils and caused additional flooding. Data from annual benthic macroinvertebrate surveys completed at 5 sites in the Upper Esopus Creek, a premier trout stream in the region, during August 2009–2011 (before the floods) were compared to data collected from the same sites in September 2011, November 2011, March 2012 and August 2012 (after the floods). The impact, rate of recovery and the factors which might affect the resilience of benthic macroinvertebrate communities were evaluated. The results of biological water quality assessment metrics immediately after the floods resembled those of highly polluted waters, yet severe floods were the only disturbance. Prior to the floods, standard biological assessment metrics showed that communities were not impacted and water quality was pristine. A large decrease in macroinvertebrate density was evident in the September 2011 surveys following the floods and bioassessment metrics reflected highly degraded water quality conditions. Most community metrics rebounded in 3–7 months (November 2011 and March 2012), and full recovery was evident in 12 months (August 2012) which suggests that macroinvertebrate assemblages are relatively resilient to the effects of extreme floods in these low-order streams. Therefore, macroinvertebrate samples collected from a flood-impacted stream before full recovery occurs might reflect loss of diversity and abundance from the flood disturbance and incorrectly attribute the impact to impaired water quality. The strong short-term impacts and the relatively rapid recovery of macroinvertebrate communities following catastrophic floods have important ramifications for routine bioassessment programs considering changing hydrologic regimes in streams across the Northeast and elsewhere.

Ecoregion approach in the assessment of aquatic ecosystems in the west of Gaziantep (Turkey): Application of diatom metrics

Abstract The biological assessment of surface water quality is becoming more important to evaluate the deterioration of aquatic ecosystems and to accomplish environmental sustainability since the implementation of EU Water Framework Directive (WFD). This study as the first attempt was organized to evaluate the ecological status of 17 freshwater bodies in the West of Gaziantep catchment by using diatom metrics. A total of 70 diatom assemblages were identified during the present study. The first two axes of canonical correspondence analysis (CCA) explained 0.962 and 0.945 of diatom assemblages–environment correlations for streams and reservoirs, respectively. According to the CCA, nutrients (e.g., P-PO4 and N-NO3) and metal ions (e.g. Cr, Ni, Pb, and Cu) strongly affected the distribution of diatom assemblages among the water bodies. Among the studied surface waters, Karanlik stream had the highest scores of 3.30, 3.39, and 2.39 due to the TIT–Trophic Index Turkey, TI–Trophic Index, and EPI-D–Eutrophication and/or Pollution Index-Diatom, respectively. The results indicated that this stream had a bad ecological condition when the EPI-D showed a poor condition. The occurrence of pollution-tolerant taxa, associated with high nutrients and electrical conductivity (EC), confirmed the ecological conditions of this stream. On the other hand, Cinarli (TIT = 2.23) and Yamacoba (TIT = 1.96) streams were of good ecological condition and had relatively low EC and nutrients. The presence of pollution-sensitive species in Cinarli and Yamacoba streams (Meridion circulare, Cymbella affinis, Halamphora veneta, and Cymbella excisa) endorsed the ecological status of it. The loading of organic and inorganic nutrients from livestock farming, agricultural land-use, and settlements could impact the water quality of the sampling stations in this catchment. The present study emphasized the importance of the evaluation of ecological integrity based on the biological and chemical characteristics of ecosystems. Diatom indices were used herein reflected efficient results for the separation of the ecological conditions of the sampled stations. Ecological preferences and occurrences of diatom assemblages and the significant positive correlation criterion with P-PO4 confirmed the suitability of TIT for assessing the ecological status of the sampling stations. All of these results suggest that the ecological status of water bodies should be evaluated due to the indices developed in their ecoregions.

An ecological assessment of six major streams in West Virginia’s Northern Panhandle

The Northern Panhandle is a culturally distinct, historically foundational region of West Virginia. Lying centrally within the Allegheny Plateau, its terrain is characterized by razorback ridges and steep, winding valleys, producing a dendritic stream pattern that drains westward into the Ohio River. This high-density stream network is nested within the urban centers of the Upper Ohio Valley; coupled with the region’s intensive coal, oil and gas resource extraction, surface waters in the Northern Panhandle are at an elevated risk of degradation. A paucity of biological water quality assessment has been conducted for streams in the Northern Panhandle, leaving our understanding of current impairments poorly understood, and our ability to evaluate restoration opportunities uncertain. We propose a comprehensive ecological assessment of six major streams in West Virginia’s Northern Panhandle. Tomlinson Run and Kings Creek each comprise HUC-12 watersheds, have less-developed catchments, and are more highly recreated. Cross Creek, Buffalo Creek, Wheeling Creek and Fish Creek each comprise HUC-10 watersheds, and have varying levels of development within their catchments. The effects of land use on watersheds occur across multiple scales (physical, chemical and biological), so the primary drivers of change are often difficult to disentangle. We will analyze water chemistry variables and multiple parameters of macroinvertebrate community data (diversity, biomass and functional feeding groups) to parse out these drivers. Our goals are to determine the ecological health of these streams and better understand the effects of land use on stream ecosystems in the Northern Panhandle.

Biological water quality assessment in the degraded Mutara rangelands, northeastern Rwanda

Rwanda is a heavily overpopulated country that also suffers from overstocking with livestock, especially following the return of war refuges after the civil war (1991–1995). At present, approximately 20% of the human population in Nyagatare District in northeastern Rwanda has no access to clean drinking water and sanitation. We used a biotic index based on the presence of selected families of aquatic macroinvertebrates, derived from the “Tanzania River Scoring System” (TARISS), to assess water quality at N = 55 sites in the Mutara grasslands in Nyagatare District. Poor water quality became evident across most sampling sites both in the Muvumba (mean ± SE TARISS score 5.25 ± 0.10) and Karangazi Rivers (4.79 ± 0.12). Using a general linear model, we asked whether direct effects of land use forms and input of anthropogenic wastewater have an impact on water quality. Our results found no immediate effects of both forms of disturbance/pollution, probably because overall water quality was already poor. Our study is intended to serve as a starting point for continuous monitoring of water quality in the Mutara rangelands in NE Rwanda. The method applied here is cost-efficient, requires only basic equipment, and training local students to apply this technique can provide a solid basis for its implementation in future surveys related to public health.

Using benthic macroinvertebrates as indicators for assessment the water quality in River Nile, Egypt

ABSTRACTMacrobenthic invertebrate’s species are differently sensitive to a biotic and biotic parameters in their environment. So they are used as bioindicators of stat and water quality of aquatic environment. The main objective of this research is using benthic invertebrates for biological assessment of water quality. Twenty-three stations along River Nile from Aswan to Cairo were selected for sampling of benthic macroinvertebrates. Benthic fauna were collected seasonally by a Naturalist Rectangle Dredge with a net 500 µm mesh size. During the monitoring period (four seasons), forty taxa were identified. They belong to benthos sensitive individuals (25%) and medium tolerant benthos (10%) and tolerant benthos individuals (65%). Relations between macrobenthic communities and circumstances of aquatic ecosystem have been lately used to perform the Biological Monitoring Water Quality (BMWQ) score to evaluate quality level in River Nile water. The total BMWQ (T-BMWQ) score and the average BMWQ (A-BMWQ) score are calculated, and their relations with MacArther, Margalef, Menhinick diversity indices and family richness are also examined. BMWQ scores are more subtle measures to assess the response of macroinvertebrates to organic pollution than diversity indices and total population density. However, the A-BMWQ score is more sensitive to changes in family composition than the T-BMWQ score, whereas T-BMWQ score is more subtle to family richness and size of sample. A-BMWQ score is suggested for the biological evaluation of freshwater quality. Also Trent Biotic Index (TBI) was calculated in each station. All these biological indices examined in this study using benthic macroinvertebrates proved that some stations in Nile River were classified as good water quality, most of studied stations were moderate water quality and very few stations were classified as poor water quality.