1. Diatoms as Bioindicators of Water Quality Cassandra Messina April 19, 2005 ECOL 475

2. Some Diatom Background Occur only as single cells or chains of cells 285 genera and 10,000-12,000 recognized species Diversity is rivaled among the algae only by the green algae Probably the most numerous of eukaryotic aquatic organisms In terms of primary productivity, the most important aquatic photosynthesizers

3. Pennate Diatoms Bilateral symmetry Two large, platelike plastids Raphid pennates Araphid pennates

4. Centric Diatoms Cylindrical cells Radial symmetry Many plastids

5. Water Quality in Streams Pennate diatoms dominated Parameters tested: pH % dissolved oxygen saturation Biological oxygen demand (BOD) Total nitrogen and phosphorous Amount of inorganic nitrogen

6. Agricultural Pollution Due to nutrient runoff and erosion Benthic algae to evaluate water quality Analyzed variables: pH Temperature Turbidity Total dissolved nitrogen, phosphorous, and organic carbon

7. Streams of the Kathmandu Valley and Middle Hills Assess stream character, water chemistry, and habitat structure Poor water quality due to release of industrial, communal, and domestic sewage without sufficient treatment Streams of the Kathmandu Valley had a higher percentage of pollution tolerant species than streams of the Middle Hills

8. Works Cited Graham, et.al. 2000. Algae. p241. Juttner, et.al. 2003. Diatoms as indicators of stream quality in the Kathmandu Valley and Middle Hills of Nepal and India. Freshwater Biology 48 (11): 2065- 2085. Kitner, et.al. 2003. Littoral diatoms as indicators for the eutrophication of shallow lakes. Hydrobiologia 506 (1-3): 519-524. Sonneman, et.al. 2001. Effects of urbanization on the streams of the Melbourne region, Victoria, Australia. Freshwater Biology 48 (4): 553-565. Tien, Chien-Jung. 2004. Some aspects of water quality in a polluted lowland river in relation to the intracellular chemical levels in planktonic and epilithic diatoms. Water research 38 (7): 1779-1790. Vilbaste, Sirje. 2004. Application of diatom indices in the evaluation of the water quality in Estonian streams. Proceedings of the Estonian Academy of Sciences, Biology, Ecology 53 (1): 37-51. Warwick, et.al. 2004. Benthic algae as bioindicators of agricultural pollution in the streams and rivers of southern Quebec (Canada). Aquatic Ecosystem Health and Management 7 (1): 43-58.