scholarly journals The biological integrity of streams and channels draining into the Rwizi River system in Western Uganda

Author(s):  
Jeninah Atwebembeire ◽  
Morgan Andama ◽  
Joel Bazira ◽  
Julius Bunny Lejju ◽  
Julius Tumusiime ◽  
...  

Rwizi River, often called the life-line river, supports over five million people in Western Uganda and is a major contributor of freshwater to Lake Victoria. Surrounded by a large and rapidly growing population, the river has suffered anthropogenic disturbances whose impact on the integrity of the system is a subject of concern. Aquatic macroinvertebrates, used globally to monitor both short- and long-term environmental conditions, were thus used to assess the biological integrity of streams and channels draining into the river system. Macroinvertebrates were sampled for six months in 2017 encompassing the wet and dry seasons using the kick net sampling method. The macroinvertebrates were identified morphologically using peer reviewed identification keys and their pollution sensitivity scored using the Tanzanian River Scoring System (TARISS). The Shannon diversity index was computed per site and related to average score per taxon (ASPT). We collected a total of 5442 macroinvertebrates belonging to 54 families dominated by Chironomidae (29.1%). Macroinvertebrate diversity increased with ASPT (r = 0.57; N = 131; P = 0.000). The water quality was generally poor and was not affected by the season (t = 1.03; df = 64; P = 0.303) though sites had different water quality (F = 11.32; df = 20; P = 0.000) attributed the degree of anthropogenic disturbance. We concluded that river Rwizi system is highly degraded and thus recommend restoration of the entire catchment. Aquatic macroinvertebrates are good indicators of long-term conditions but less sensitive to short-term changes. Multiple approaches, biological and chemical, are encouraged during the restoration process.

2019 ◽  
Vol 11 (2) ◽  
pp. 33-42
Author(s):  
Thanh Giao Nguyen

The aquatic environment and zoobenthos are closely related in a water body. In recent years, the use of zoobenthos to evaluate water quality is getting more attention as this approach is less polluting and less costly. This study was conducted to assess the diversity of zoobenthos in the canals affected by leachate and agricultural activities. Five sediment samples were collected in two campaigns, one in April and one in October 2018. Water samples were also collected at the same time for zoobenthos to assess the water quality and serve as a reference for assessing the effectiveness of using zoobenthos as water quality indication. In total, 17 species of zoobenthos belonging to six families and four classes were identified, of which Limnodrilus hoffmeisteri and Tendipes species being present regularly at sampling sites through the surveys. The calculations of the Shannon-Wiener diversity index (H'), rapid bioassessment protocol (RBP III), and associated average score per taxon (ASPT) indices based on species composition indicated that the water environment surrounding the landfill was moderately to severely polluted. However, the water quality index (WQI) calculated based on the physical and chemical properties shows that the level of water pollution in canals was less than that evaluated using zoobenthos. This can be explained by the fact that zoobenthos also affected the properties of sediments which depend on the water column. The findings in this study showed that the aquatic environment around the landfill is heavily contaminated as result of waste disposal and agricultural activities. The use of both zoobenthos combined with physical and chemical indicators could be useful in assessing the canals’ water status. Môi trường nước và động vật đáy có liên quan mật thiết với nhau trong một thủy vực. Trong những năm gần đây, việc sử dụng động vật đáy để đánh giá chất lượng môi trường nước mặt được quan tâm vì phương pháp này ít gây ô nhiễm môi trường và ít tốn kém chi phí. Nghiên cứu được tiến hành để đánh giá sự phân bố của động vật đáy trong hệ thống kênh rạch chịu tác động từ nước rỉ rác và các hoạt động sản xuất nông nghiệp. Năm mẫu động vật đáy được thu hai đợt, đợt 1 vào tháng 4 và đợt 2 vào tháng 10 năm 2018. Mẫu nước cũng được thu để đánh giá chất lượng nước và làm cơ sở đánh giá hiệu quả của việc sử dụng động vật đáy làm chỉ thị chất lượng môi trường nước. Kết quả nghiên cứu cho thấy thành phần động vật đáy phát hiện 17 loài thuộc 6 họ và 4 lớp, trong đó các loài Limnodrilus hoffmeisteri và loài Tendipes hiện diện thường xuyên ở tất cả các điểm thu mẫu qua hai đợt khảo sát. Dựa vào thành phần loài tính toán các chỉ số Shannon-Wiener (H’), chỉ số đánh giá nhanh sinh học (RBP III), và chỉ số tính điểm trung bình bình theo họ (ASPT) cho thấy môi trường ô nhiễm rất nặng trong khi đó chỉ số WQI được tính toán dựa vào các chỉ tiêu lý hóa cho thấy mức độ ô nhiễm nước ở kênh xung quanh bãi rác chỉ ở mức nhẹ hơn. Như vậy, việc sử dụng động vật đáy cho kết quả đánh giá chất lượng nước với mức độ ô nhiễm cao hơn. Điều này có thể giải thích là do động vật đáy chịu ảnh hưởng bởi đặc tính nền đáy và cột nước bên trên nền đáy. Kết quả nghiên cứu cho thấy môi trường nước xung quanh bãi rác bị ô nhiễm nặng do xả thải và hoạt động sản xuất nông nghiệp. Việc sử dụng động vật đáy kết hợp với các chỉ tiêu lý, hóa có thể hữu ích hơn trong việc đánh giá hiện trạng nước kênh.


2018 ◽  
Vol 1 (2) ◽  
pp. 29
Author(s):  
Semir Dorić ◽  
Adnan Čučuković

Benthic macroinvertebrata (macrozoobenthos) are widely used for water quality assessments because they are considered as one of the best indicators of habitat quality in running waters, very conventionally called as „river health“. Benefits of research on macroinvertebrates include the quick assessment of biological resources for conservation purposes and the detection of water pollution. This research was performed in accordance with the EU Water Framework Directive (WFD). AQEM methodology was used for macrozoobenthos specimen collection from six sampling sites along quarry Ribnica’s main hydroecosystems – the Forest creek (quarry's water supply system) and the estuary of the river Ribnica (Mar-Sep, 2016). Laboratory analyses were carried out for the purpose of separation, counting and final taxonomic identification of organisms. Cluster analysis and diversity index computing were performed using BioDiversity Pro 2.0 software. Our findings suggest the existence of 15 taxa from classes Gastropoda, Hirudinea and Insecta with a total number of 454 sampled individuals. The Insecta class was the most numerous one with respect to the species found, including larvae of the orders Ephemeroptera, Plecoptera, Trichoptera and Diptera. Shannon-Weaver and Simpson diversity indices revealed highly developed communities of aquatic macroinvertebrates at all sampling sites. Water quality along quarry Ribnica based on macrozoobenthos indicator species of saprobity was found to be classified into moderate, low and non to very low polluted (Quality class I-II). Further long-term monitoring studies of macrozoobenthos are necessary in order to keep track of the good ecological status (GES) observed at quarry Ribnica’s aquatic ecosystems.


2020 ◽  
Vol 12 (1) ◽  
pp. 7-16
Author(s):  
Thanh Giao NGUYEN

The study aimed to evaluate water quality at Bung Binh Thien Lake, An Giang Province, Vietnam using Shannon-Wiener species diversity index (H’) and associated average score per taxon (ASPT) calculated from composition of phytoplankton and zoobenthos. The water quality index (WQI) was used as the reference for the quality of surface water. The samples of surface water quality, phytoplankton, and zoobenthos were simultaneously collected at 11 sites in the dry season. The results showed that WQI (57-88) classified water quality from good to medium, H’ calculated using phytoplankton species (1.12-2.71) presented water quality from medium to bad whereas, (H'z) calculated (0 to 2.07) and ASPT (2-4.21) calculated from zoobenthos species divided water quality from bad to very bad. The findings revealed that assessing water quality should not totally only relied on diversity indices (H’, ASPT) but also carefully consider compositions of phytoplankton and zooplankton. In addition, interpretation of the biodiversity indices for water quality examination should involve the experts in the relevant fields. Nghiên cứu nhằm đánh giá chất lượng nước tại hồ Bung Binh Thiên, tỉnh An Giang, Việt Nam sử dụng chỉ số đa dạng loài Shannon-Wiener (H’) và chỉ số tính điểm trung bình bình theo họ (ASPT) được tính từ thành phần của phiêu sinh thực vật và động vật đáy. Chỉ số chất lượng nước (WQI) được sử dụng tham chiếu cho chất lượng nước mặt. Các mẫu chất lượng nước mặt, phiêu sinh thực vật thực vật và động vật đáy được thu đồng thời tại 11 địa điểm trong mùa khô. Kết quả cho thấy WQI (57-88) phân loại chất lượng nước từ tốt đến trung bình, H’p được tính dựa vào các loài phiêu sinh thực vật (1.12-2.71) thể hiện chất lượng nước từ trung bình đến xấu trong khi, H’z (0- 2.07 ) và ASPT (2-4,21) được tính toán từ các loài động vật đáy phân loại chất lượng nước từ xấu đến rất xấu Kết quả nghiên cứu cho thấy đánh giá chất lượng nước không chỉ hoàn toàn dựa vào các chỉ số đa dạng (H’, ASPT) mà còn xem xét cẩn thận thành phần loài của phiêu sinh thực vật và động vật đáy. Ngoài ra, việc giải thích các chỉ số đa dạng sinh học nhằm tra chất lượng nước cần có sự tham gia của các chuyên gia trong các lĩnh vực liên quan.


2020 ◽  
Vol 1 (36) ◽  
pp. 39-50
Author(s):  
Giao Thanh Nguyen

The study aimed to evaluate water quality at Bung Binh Thien Reservoir, in An Giang Province, Viet Nam using Shannon-Wiener species diversity index (H’) and associated average score per taxon (ASPT) calculated from composition of phytoplankton and zoobenthos. The water quality index (WQI) was used as the reference forthe quality of surface water. The samples of surface water quality, phytoplankton, and zoobenthos were simultaneously collected at 11 sites during the dry season. The results showed that WQI (57-88) classified waterquality from good to medium, H’ calculated using phytoplankton species (1.12-2.71) presented water quality from medium to bad where as, H’z calculated (0 to 2.07) and ASPT (2-4.21) calculated from zoobenthos species divided water quality from bad to very bad. The findings revealed that assessing water quality should not totally rely on diversity indices (H’, ASPT), but compositions of phytoplankton and zooplankton should also be taken into consideration.


2021 ◽  
pp. 1-22
Author(s):  
Nguyen T. Giao ◽  
Huynh T.H. Nhien ◽  
Truong H. Dan

The use of zoobenthos to evaluate water quality has gained considerable interest due to its low cost and environmental friendliness. This study analyzed water and zoobenthos samples at 13 sites in the water bodies in An Giang province in the rainy season (on March) and dry season (on September) in 2018. The results showed that the surface water was contaminated by organic matters, suspended solids and coliforms. There was occurrence of 28 species of zoobenthos divided into five classes including Oligochaeta, Polychaeta, Insecta, Gastropoda, and Bivalvia in which Bivalvia was the most diverse class accounting for 75%. The densities of zoobenthos in the dry and wet season were from 30 divided into three clusters for the dry season and six clusters for the rainy season indicating seasonal variation of zoobenthos composition possibly due to variance of water and sediment characteristics. The results of Pearson correlation indicated that the composition of zoobenthos was strongly correlated with temperature, pH, N-NH4+ and N-NO3-. Using water quality index (WQI), Shannon-Wiener diversity index (H’) and associated average score per taxon (ASPT) for water quality assessment revealed that water quality ranges from medium (from α to β- mesosaprobe) to heavy pollution (Polysaprobe). There was inconsistency between using physicochemicals and diversity index of zoobenthos for water quality identification leading to the use of zoobenthos for water indication could result in misadjustment of water quality. Further study should investigate the relationship between zoobenthos and water quality in different ecological areas to better indicate role of zoobenthos in quick diagnose water quality.


2021 ◽  
Vol 38 (4) ◽  
pp. 399-409
Author(s):  
Hazel Baytaşoğlu ◽  
Ahmet Mutlu Gözler

In this study, it was aimed to evaluate the water quality of the Çoruh Basin using BMWP (Biological Monitoring Working Party) index, ASPT (Average Score Per Taxon) index, Shannon-Wiener Diversity Index, EPT (Ephemeroptera Plecoptera Trichoptera taxa), EP (Ephemeroptera Plecoptera taxa) index scores and benthic macroinvertebrates. The benthic macroinvertebrates were collected from 54 stations at the Çoruh basin between 2014-2016 years. Standard hand net (D-frame net) and Ekman-Birge grab were used as sampling tools. As a result of the diagnoses, a total of 7246 individuals belonging to Insecta, Crustacea, Mollusca, Oligochaeta and Plathyhelminthes were obtained. It was determined that the most dominant group was Insecta and the rarest group was Plathyhelminthes. It was observed that the BMWP score ranged between 5 and 94, and the lowest and highest number of families detected in the stations were 1 and 18, respectively. It was determined that the Shannon Wiener diversity index value was between 0.54-2.20, therefore the basin streams generally showed moderate pollution. The results of BMWP index show that the basin streams had mostly show 3rd and 4th class water quality and also biodiversity decreases with the deterioration of the riverbed or exposure to pollution.


2013 ◽  
Vol 39 (1-6) ◽  
pp. 323-420 ◽  
Author(s):  
John H. Chick ◽  
Lori A. Soeken-Gittinger ◽  
Eric N. Ratcliff ◽  
Eric J. Gittinger ◽  
Benjamin J. Lubinski ◽  
...  

We present information gleaned from 10 years of data collected by the water quality component of the Upper Mississippi River Restoration Environmental Management Program’s Long Term Resource Monitoring Program (LTRMP) from Pool 26 of the Upper Mississippi River System (UMRS). The Pool 26 reach of the UMRS includes the confluence with the Illinois River, and the confluence with the Missouri River just downstream of Mel Price Locks and Dam. The surrounding communities in both Illinois and Missouri benefit greatly from the natural resources provided by these rivers. We estimate that annual expenditures are 55 million for fishing and hunting, respectively, in the region surrounding Pool 26 based on license sales and state expenditure data from the U.S. Fish and Wildlife Service. Additionally, there is a commercial fishery active in Pool 26, recreational boating, and the UMRS provides drinking water for many municipalities in this region. Finally, the Upper Mississippi River System is a major transportation system, and Pool 26 receives the greatest amount of barge traffic for any river reach in the UMRS. The LTRMP began collecting data in 1988, but the first years of the program were experimental. Currently followed monitoring protocols for water quality and fish monitoring were adopted in 1993; however, a major flood event in that year prevented full data collection for that year. Data from the LTRMP water quality component demonstrate that Pool 26 is a highly productive river reach. Long-term averages of chorophyll-a, total phosphorous, total nitrogen, and total inorganic solids are comparable to levels in eutrophic to highly eutrophic lakes. The average current velocity in the main channel of the Mississippi River in Pool 26 ranges from 0.364–0.414 m/sec. during the summer and fall. Even during the lowest discharge levels in a year, the reach has a residence time no longer than 2.7 days. Discharge was significantly related to many water quality parameters, including Secchi depth, turbidity, total suspended solids, total nitrogen, nitrate-nitrite, and total phosphorus. We observed a significant linear increase in mean water temperature in the main channel from 1994 to 2004. When these data were analyzed by season, positive linear trends were found during the spring (0.515°C per year) and fall (0.646°C per year). Continued monitoring is necessary to determine if these observations represent short term fluctuations or long-term trends and to detect any related effects on this river reach.


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