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TRAINING REPORT ON AQUATIC INVERTEBRATES (Draft) Introduction This training has been offered under the UN’s mission in Rwanda aimed to develop scientific capacity in the country and specifically to develop a center of excellence in biodiversity conservation where several scientists of CoEB nodes and other Government institutions were equipped with skills in aquatic invertebrates, stream habitat description and measurements of factors that influence their distribution. The training took place from 27th August to 2nd September 2012 at the National University of Rwanda’s Zoology department laboratory and in various fields of the country. The training composed by classroom lectures, field visits, samples identification, and data /samples analysis. The training had the following objectives: Train scientists in different methods of sampling aquatic insects and preserving them as vouchers for future reference, Develop the capacity of trainees in aquatic invertebrate identification at least to Family level of identification, To develop an understanding of the ecological relationships between aquatic insects and their environment and Train scientists in data analysis techniques to be able to develop metrics for water quality assessments at different sites. After classroom lectures, trainees started the field visits where they visited various fields such as: Nyabugogo site, Mwogo site, Bugesera/Kamatana reservoir, Bugesera/Rumila lake, Akagera floodplain wetland, and Songa/ ISAR. Nyabugogo site: This site was sampled at 12h30. It is a river with .Widith: 6.95m, depth on one edge 29cm and depth on other edge 76cm. This river is covered by the vegetation and degraded by the urbanisation. Mwogo wetland site: This wetland was sampled at 08h30. It has a depth of 45cm and the water was blackish due to decomposition processes and covered by Azolafilucolloides. It is surrounded by Cyperus papyrus, Cyperus spp. The sampled habitat was in pool at the edge of a wetland, up stream of which is agricultural activity. Bugesera/ Kamatana reservoir: This site was sampled at 10h15 with the depth on the edge of 52cm. It is an open area surrounded by Cyperuspapyrus ,Cyperuslatifolium. The sampled site is water reservoir constructed to serve the surrounding communities. The reservoir has high biodiversity value as evidenced from several water fowls seen at the site. Bugesera/Rumila Lake: This lake was sampled at 04h00 p.m. This lack is dominated by human activities (cultivation of beans and La pallisehoter) where cultivation area is up to the lake shores. As a consequence, almost no buffer is available to protect the lake from pollution sources Akagerafloodplain wetland: This wetland has 1.95m of width and it was modified by human activities. It is dominated by by Cyperuslatifolium, and Eichhorniacrassipes and slow flowing. The sampled site is located within the Akagera river floodplain and is impacted variously by human activities such as agriculture and road networks. Songa/ISAR: This site has 30cm and 0.8m of depth and width respectively. It was sampled at 04h30 p.m after some rains the bottom is sandy. The site is covered by Phragmites, Pennisetum spp ,Cyperus latifolium, Ludwigia abyssinica and water colour was milky because of clay soils in the area. The site is located in a rural area and the main land use type is cattle grazing and as such the water may be impacted by deposition of wastes including cattle dung and other chemicals used in cattle spraying. Physicochemical measurements: During this training, different physicochemical parameters that may influence aquatic invertebrate diversity were introduced to the trainees. Trainees were tough how to handle and prepare various equipment to measure different variables such as River width (m), River/pond depth, Flow speed, Electrical conductivity (µS), Total Dissolved Solids (TDS), PH, Turbidity (NTU), and Dissolved oxygen. Participant measuring dissolved oxygen at a site Aquatic insect sampling Aquatic insects sampling in the field was demonstrated using two methods (standing water (lentic) and flowing water (lotic)). The D-frame (Dipnet) was demonstrated for use in non wadeable and very deep waters. The sampled species were cleared of debris by rinsing in clean water and aquatic insects sorted out of the debris using forceps and preserved in 10% formalin thereafter, the collected specimens were labeled where date, bottom type, and name of collectors were highlighted. Trainees sorting samples in the field In the laboratory The trainees were explained more about how water bodies function, differences between rivers and lakes in terms of habitat and functioning. The importance of aquatic insects as indicators of water quality was demonstrated using the different tolerance categories from the very tolerant taxa such as Oligochaetes and blood worms (Chironomidae) found in poor quality water to the highly sensitive taxa such as the mayflies (Ephemeroptera), stone flies (Plecoptera) and cadisflies (Tricoptera) found in pristine habitat with good quality water. Aquatic invertebrate identification Aquatic invertebrate taxonomy was introduced to the trainees using samples collected from the field. Trainees sorted invertebrate groups based on their morphological characteristics such as body shape, type of mouth parts and possession of and number of legs and wings and then they identified them by using the field guide to aquatic insects of Southern Africa (Geber and Gabriel 2002). Data analysis Data analysis was done by using Microsoft excel. Total number (taxa richness) for each site was then determined and diversity indices calculated for each sites using Species Diversity and Richness (SDR 4) package. Cluster analysis was also used to determine similarities in taxa composition among the sites sampled. Results/interpretations A total of 18 invertebrate families were identified with certainty by the trainees. Most of the invertebrates identified were of tolerant category implying that most of the sites were of poor water quality and generally degraded. The highest dissolved oxygen value was recorded at Nyabugogo stream where water was fast flowing compared to the other sampled sites. Intermediate dissolved oxygen levels were recorded at the reservoir and lake sites where photosynthetic activity by macrophytes and phytoplanktonmay be responsible for the relatively high oxygen levels. Turbidity was lowest at Kamatana reservoir and highest at Nyabugogo stream. In terms of domestic use of the water at sampled sites, the Nyamatana water would be ideal for human use with minimal treatment costs while the Nyabugogo water would be the most expensive to treat before it becomes usable by humans. Songa site presented a high taxa richness and a low tolerance and also a rich water quality while Kamatana showed a high variation in Shannon’s diversity index. Recommendations Establishment of a well equipped aquatic sciences laboratory (equipments & books) Introduction of bachelor’s degree in aquatic sciences to include aquatic biodiversity conservation If logistically feasible sampling of aquatic insects should also be carried out in pristine conditions such as in streams and rivers located within National parks in Rwanda as diversity would be extremely high there Conclusion The training will impart practical skills to the trainees on how to identify aquatic invertebrates and be able to relate the findings to the quality of water resources in the studied rivers. The trainees are expected to be trainers of other people within the country and through a multiplier effect create a critical mass of aquatic invertebrate expertise in the country.