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.