scholarly journals Structure of Benthic Macroinvertebrate Communities in the Rivers of Western Himalaya, Nepal

Geosciences ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 150
Author(s):  
Ram Devi Tachamo Shah ◽  
Subodh Sharma ◽  
Deep Narayan Shah ◽  
Deepak Rijal
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Benthic Macroinvertebrates ◽  
Western Himalaya ◽  
Freshwater Ecosystems ◽  
Benthic Macroinvertebrate ◽  
Macroinvertebrate Communities ◽  
River Systems ◽  
River Continuum ◽  
River Types

According to River Continuum Concept (RCC), channel morphology, including sediment loads and channel width, river habitat, flow regimes and water quality, differs from the tributary to the downstream river’s mainstem, allowing shifts in faunal composition from dominance of shredders to collectors downstream, respectively. Tributaries are responsible for contributing organic carbons, nutrients and water. However, such knowledge is still limited in the monsoon-dominated river systems of the Himalaya. The study was conducted in the river’s mainstem and tributaries of the Karnali River Basin, which are glacier and spring-fed river systems, respectively, in the western Himalaya, Nepal. A total of 38 river stretches in the river’s mainstem and tributaries were sampled during post-monsoon and pre-monsoon seasons in the years 2018 and 2019. Water quality parameters, such as pH, temperature, electrical conductivity, total dissolved solids, dissolved oxygen, alkalinity and hardness, and the benthic macroinvertebrates were studied. Ten subsamples of benthic macroinvertebrates were collected following the multi-habitat sampling approach at each site. High taxa richness was recorded in tributaries compared to the river’s mainstem while abundance was similar between river types. Non-metric multidimensional scaling (NMDS) formed two distinct groups, reflecting high similarities in benthic macroinvertebrate composition within the tributaries and river’s mainstem rather than between river types. Redundancy analysis (RDA) indicated water temperature and pH as major environmental predictors for benthic macroinvertebrate variability between river types. Therefore, river type-based conservation efforts that account for upstream–downstream linkages of aquatic biota and resources in freshwater ecosystems can ensure the ecological integrity of the whole river basin.

scholarly journals Assessing Spatial Distribution of Benthic Macroinvertebrate Communities Associated with Surrounding Land Cover and Water Quality

2019 ◽  
Vol 9 (23) ◽  
pp. 5162 ◽  
Author(s):  
Dong-Kyun Kim ◽  
Hyunbin Jo ◽  
Kiyun Park ◽  
Ihn-Sil Kwak
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Spatial Distribution ◽  
Benthic Macroinvertebrates ◽  
Benthic Community ◽  
Benthic Macroinvertebrate ◽  
Macroinvertebrate Communities ◽  
Ambient Water ◽  
Accessible Information ◽  
The Impact

The study aims to assess the spatial distribution of benthic macroinvertebrate communities in response to the surrounding environmental factors related to land use and water quality. A total of 124 sites were surveyed at the Seomjin River basin in May and September 2017, respectively. We evaluated the abundance and composition of benthic macroinvertebrate communities based on nine subwatersheds. Subsequently, we compared the benthic information with the corresponding land use and water quality. To comprehensively explore the spatiotemporal distinction of benthic macroinvertebrate communities associated with those ambient conditions, we applied canonical correspondence analysis (CCA). The CCA results explicitly accounted for 61% of the explanatory variability; the first axis (45.5%) was related to land-use factors, and the second axis (15.5%) was related to water quality. As a result, the groups of benthic communities were distinctly characterized in relation to these two factors. It was found that land-use information is primarily an efficient proxy of ambient water quality conditions to determine benthic macroinvertebrates, such as Asellus spp., Gammarus spp., and Simulium spp. in a stream ecosystem. We also found that specific benthic families or genera within the same groups (Coleoptera, Diptera, Ephemeroptera, and Trichoptera) are also differentiated from ambient water quality changes as a secondary component. In particular, the latter pattern appeared to be closely associated with the impact of summer rainfall on the benthic community changes. Our study sheds light upon projecting benthic community structure in response to changes of land use and water quality. Finally, we conclude that easily accessible information, such as land-use data, aids in effectively characterizing the distribution of benthic macroinvertebrates, and thus enables us to rapidly assess stream health and integrity.

scholarly journals Optimisation of the Monitoring Strategy of Macroinvertebrate Communities in the River Dender, in Relation to the EU Water Framework Directive

2002 ◽  
Vol 2 ◽  
pp. 607-617 ◽  
Author(s):  
Tom P. D’heygere ◽  
Peter L.M. Goethals ◽  
Niels De Pauw
Keyword(s):  
Water Quality ◽  
Water Framework Directive ◽  
Eu Water Framework Directive ◽  
Nutrient Loads ◽  
Macroinvertebrate Communities ◽  
Monitoring Strategy ◽  
Biological Water ◽  
River Types ◽  
Biological Water Quality ◽  
The Eu

The Dender basin in Flanders (Belgium) was used as a case study to implement the European Union (EU) Water Framework Directive. During the last 5 years, ample research on pollution loads and ecological water quality has been done on the Dender River. In addition to biological sampling of macroinvertebrates and fish, automated measurement stations were also used to investigate the spatial-temporal variability of the physical-chemical water quality. This research revealed that the pollution of the Dender River is highly variable. The high nutrient loads result in severe algae blooms during summer, leading to very complex diurnal processes. In this paper, the monitoring strategy for the assessment of the biological water quality in the Dender basin has been reviewed in relation to the EU Water Framework Directive. For this, seasonal macroinvertebrate data were collected and assessed. General trends and hidden structures in these data were analysed by means of classification trees, using different inputs (seasons, river types, and subbasins). Validation of the results was obtained by applying statistical methods. Analysis about the presence and abundance of the macroinvertebrates revealed that there is a distinct difference between the biological water quality in the Dender stem river and its tributaries. There are also seasonal differences between the macroinvertebrate communities when the Dender and its tributaries are examined separately. An optimised monitoring strategy is proposed based on these results and the EU Water Framework Directive. This includes two monitoring campaigns in summer and winter every 3 years. Furthermore, a cyclic monitoring scheme was developed to minimise sampling efforts.

The effect of thermal effluent, before and after macrophyte harvesting, on standing crop and species composition of benthic macroinvertebrate communities in Lake Wabamun, Alberta

1982 ◽  
Vol 60 (12) ◽  
pp. 3196-3205 ◽  
Author(s):  
Joseph B. Rasmussen
Keyword(s):  
Species Composition ◽  
Benthic Macroinvertebrates ◽  
Standing Crop ◽  
Tubifex Tubifex ◽  
Benthic Macroinvertebrate ◽  
Macroinvertebrate Communities ◽  
Plant Detritus ◽  
Chironomid Species ◽  
Before And After ◽  
Heated Area

The heated area of Lake Wabamun prior to macrophyte harvesting had higher submerged macrophyte production, greater amounts of plant detritus in the sediment, and a higher standing crop of benthic macroinvertebrates than the unheated area. Species composition of the benthic macroinvertebrate community was also much different in the heated area with the warmest areas supporting a community dominated by tubificid oligochaetes (Limnodrilus hoffmeisteri and Tubifex tubifex), and the moderately heated areas supporting a community dominated by large Chironomus species (Chironomus plumosus and Chironomus atroviridis). Benthos of the unheated parts of the lake consisted mainly of smaller chironomid species such as Chironomus maturus, C. (cf.) staegeri, Polypedilum nubeculosum, Cladotanytarsus spp., and Tanytarsus spp. The heated area was subjected to mechanical macrophyte harvesting which removed the majority of the submerged macrophytes. This reduced the amount of plant detritus within the sediment and also the standing crop of benthic macroinvertebrates in the heated area. Species composition of the oligochaete-dominated community was not affected by harvesting. Species composition of the Chironomus-dominated area was greatly affected by harvesting and became more similar to that of the unheated area; densities of the large Chironomus species were reduced to low levels, while the densities of smaller chironomid species increased.

scholarly journals Community Analysis and Water Quality of Benthic Macroinvertebrates at Gwangseok stream in Korea

2019 ◽  
Vol 4 (1) ◽  
pp. 97-100
Author(s):  
Man Kyu Huh
Keyword(s):  
Water Quality ◽  
Benthic Macroinvertebrates ◽  
Community Analysis ◽  
Macroinvertebrate Community ◽  
Biotic Index ◽  
Benthic Macroinvertebrate ◽  
Biological Water ◽  
Evenness Indices ◽  
Biological Water Quality

The study was to investigate species composition and biological water quality of benthic macroinvertebrates among localities at Gwangseok stream, Jinhae city in Korea. The identified benthic macroinvertebrates were 781 individuals belonged to 19 species, 14 families, 8 orders, 5 classes and 3 phyla. The value of dominance index (DI) was varied from 0.184 (St. C) to 0.333 (St. A) with a mean of 0.235. DI was significantly different among the four regions. Beck-Tsuda's Biotic Index (BI) was varied from 7 (St. D) to 20 (St. C) with a mean of 14. Total ecological score of benthic macroinvertebrate community (TESB) was varied from 12 (St. D) to 38 (St. B) with a mean of 26.3. Average ecological score of benthic macroinvertebrate community (AESB) was varied from 1.714 (St. D) to 1.900 (St. B) with a mean of 1.821. Benthic macroinvertebrate index (BMI) ) was varied from 22.354 (St. A) to 26.474 (St. D) with a mean of 39.756. Shannon-Weaver index (H´) for mammals at the upper regions (St. A and St. B) was higher than those of low regions (St. C and St. D). Berger-Parker’s index (BPI) was varied from 0.218 (St.. C) to 0.346 (St. A). Richness (R1) was different from each other and R2 was not shown significant differences (p < 0.05). Evenness indices (E1-E5) for four stations were different from each other, however there were not shown significant differences (p < 0.05).

Impacts and solutions associated with glacier-driven river toxicity in the Cordillera Blanca, Peru

2021 ◽  
Author(s):  
Moya Macdonald ◽  
Jemma Wadham ◽  
Fiorella La Matta Romero ◽  
Jon Hawkings ◽  
Bram Willems ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Green Infrastructure ◽  
Low Ph ◽  
Glacier Retreat ◽  
Metal Species ◽  
Benthic Macroinvertebrate ◽  
Macroinvertebrate Communities ◽  
Freshwater Biodiversity ◽  
Cordillera Blanca

&lt;p&gt;Approximately 70% of the world&amp;#8217;s tropical glaciers are found in Peru, with 40% of these in the Cordillera Blanca (CB). Here, glaciers are an important source of meltwater to downstream people (~0.25 million) and ecosystems, supporting 40% of streamflow in the dry season. However, the CB has experienced high levels of glacier retreat and mass loss in recent decades, which has influenced the quantity and quality of water supply. During this time, some meltwater-fed rivers have become &amp;#8216;toxic&amp;#8217;, characterised by low pH and high metal concentrations. This toxicity has been linked to exposure of sulphide- and metal-rich rock types as glaciers retreat, and has implications for clean water supply (SDG 6), subsistence farming (contributing to SDG1 and 2), and freshwater biodiversity (SDG 15). Here, we present a comprehensive spatial analysis of water quality in the CB to understand the key drivers of worsening water quality and to predict which catchments may be vulnerable in the future. We sampled 18 glacierised catchments in the CB for geochemical and biological parameters during the dry and wet seasons. River pH ranged from 2.5 to 8.3, with two catchments highly acidic (~pH 2.5-3.8). The concentrations of several riverine metal species (including manganese, nickel, copper and a suite of rare-earth elements) were strongly negatively correlated with pH in the catchments. Additionally, most of the 40 metals analysed in rivers with low pH were present in a truly dissolved phase (&gt;90% of 0.45 &amp;#181;m filtered concentrations were &lt;0.02 &amp;#181;m), indicating high potential bioavailability and biotoxicity. Indeed, shifts in community composition of benthic macroinvertebrates indicated a replacement of sensitive benthic macroinvertebrate taxa (Limnephilidae, Hyaleliidae) in pristine rivers by more tolerant taxa (Chironomidae) in acidic rivers. We suggest that metal leaching and altitude may be important factors influencing diversity, richness and abundance of benthic macroinvertebrate communities. Here, we synthesize data on water quality and glacier retreat, offer predictions of future river toxicity and introduce a novel citizen-science, green-infrastructure initiative being developed to combat water quality degradation in the region.&lt;/p&gt;

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