at six stations along a hydraulic gradient from source to mouth, to evaluate the impact of land use on temperature, Dissolved Oxygen (DO), Biological Oxygen Demand (BOD 5 ), alkalinity and suspended solids. Upstream, where forests are conserved, minimal changes of physico-chemical parameters of water were observed. Downstream, DO was reduced, due to the increased organic matter content which increased the decomposition rate. BOD 5 and suspended solids increased downstream. Greater changes were found near agricultural areas and villages. Wetlands appear to mitigate BOD 5 and DO impacts.

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In this study, the epilithic algae of Kahuzi-Biega National Park were investigated at the first time. The samples were collected from 10 streams in between 1900 and 2400 m asl during dry season (July-August 2007). Altogether, some 170 species have been encountered and identified, belonging to 61 genera were observed. Bacillariophyceae formed the most abundant group making up 61 species from 20 genera. This was followed by the Cyanophyceae with 47 species from 12 genera, the Chlorophyceae with 30 species from 15 genera, the Desmidiaceae with 17 species from 7 genera, the Euglenophyceae with 10 species from 4 genera and the Dinophyceae represented by 5 species from 2 genera. This algal community is very diversified and balanced (Shannon Weiner index varied between 4.44-4.67, Species Diversity between 15.81-13.31 and Equitability between 0.97-0.99).

The physico-chemical characteristics of ten permanently flowing rivers from Kahuzi Biega National Park (Democratic Republic of Congo) were examined in July 2007. Water samples were collected from ten sites between 1800 and 3200 m asl and analyzed for the following chemical parameters: biological oxygen demand, total and carbonate hardness, alkalinity, total phosphorus, nitrogen, nitrate, and ammonia. Discharge, current velocity, temperature, and oxygen saturation were analyzed on site. In general, the chemical parameters revealed relatively low concentrations compared to others rivers in the region. The rivers were cold (10℃ - 15℃), well oxygenated, had low conductivity (generally <100 µS/cm), and had pH values ranging between 5.5 and 7.6. Nitrogen and phosphorus were also low (0.086 - 0.25 µmol/L for phosphorus and 2.21 - 4.25 µmol/L for nitrogen) in all rivers. The main natural sources of nitrogen and other nutriaents are from rain and atmospheric deposition, organic matter decomposition, and fixation of molecular nitrogen from allochthonous inorganic material. In the forested rivers of Kahuzi-Biega National Park the terrestrial and riparian environments are the only sources of nitrogen and phosphorus to the river water

Monitoring of environmental parameters is one of the highest priorities in the evaluation of environmental status of water resources and in environmental protection policy. The main objectives are to understand and evaluate the water quantity and quality in order to provide water of appropriate quality to various water users. The water quantity was assessed by the measurement of runoff or discharge at specific river cross sections using floating method for surface water and bucket and stopwatch method for springs and boreholes. The quality of river water and spring was identified in terms of its physical, chemical, and biological parameters. The analyzed data were compared with standard values recommended by WHO. Macroinvertebrates were collected in the rivers using a plankton nets and 10 minutes of sampling. Identification was made at the laboratory of Malacology. Results revealed that the quality of water obtained from sampling points is generally good to use for different domestic purposes except the Idanta River and Rwembwe borehole, which need an appropriate treatment before use. All sampling points are located far from houses and latrines, which can contribute to fecal contamination. On the different sampling points, bathing and washing clothes were observed and could constitute the source of pollution of drinking water. In Idanta and Kamira Rivers animals used water for drinking while also people use this water for domestic and drinking. In the two sampling points high values of Escherichia coli * Corresponding author. K. Karume et al. 383 were found. No pollutant-taxa tolerant were found in the two monitored rivers for macroinvertebrates. Since water quality and quantity remain a major challenge in rural areas, the government should provide safe water to the population around Mikeno sector after treatment using suitable techniques.