Characterization of environmental gradients using physico-chemical measurements and diatom densities in Nairobi River, Kenya
Keywords:
artificial and natural substrates, water pollution, urbanisation, agriculture, nutrients, multiple regression analysisAbstract
Degradation of water resources due to anthropogenic activities is a major problem all over the world. Monitoring changes in water quality is expensive but essential for management of water resources. Diatom assemblages can serve as useful indicators of changes in water quality. In order to determine changes in stream water quality in an urban environment, densities of epilithic diatom communities on both natural and artificial substrates were sampled in Nairobi River, Kenya in September 2000. Sampling of water and diatoms was carried out in almost equidistant sites along a 60 km stretch of the Nairobi River. Environmental (water physico-chemical and nutrients) data was explored by Principal Correspondence Analysis (PCA) and sites split into three groups of upper-, mid- and lower stream. Most abundant diatom taxa on both substrates were selected and their relationship with environmental variables determined.
On artificial substrates, Gomphonema parvulum, Nitzschia palea and Nitzschia umbonata were the most abundant and were significantly related with total dissolved solids, nitrate, conductivity and turbidity. Temperature, altitude and pH interacted significantly with dominant diatom species on natural substrates, which included Gomphonema parvulum, Nitzschia palea and Navicula subminuscula. Non-parametric analyses showed that diatom densities in natural and artificial substrates were significantly different and were affected by different environmental variables. Our results indicate that abundant diatom species can be used to describe major types of aquatic environmental gradients and can serve as good indicators of ecological conditions in tropical streams and rivers. This study also showed that diatoms from artificial and natural substrates can be used to provide complementary information.
References
APHA (American Public Health Association). 1995. Standards methods for the examination of water and wastewater , 19th ed., Baltimore, Maryland, , USA: Port City Press.
Biggs, B. J. E. 1996. “Patterns of benthic algae in streams”. In Algal Ecology, Freshwater Benthic Ecosystems, Edited by: Stevenson, R. J., Bothwell, M. L. and Lowe, R. L. 31–55. California: Academic Press.
El-Eadel, M., Zeinati, M., El-Jisr, K. and Jamali, D. 2001. Industrial waste management in developing countries: The case of Lebanon. J. Environ. Manage., 61: 281–300.
Falkenmark, M. 2000. No freshwater security without major shift in thinking. Ten-year message from Stockholm water symposia Stockholm, , Sweden
Friedl, G. and Wüest, A. 2002. Disrupting biogeochemical cycles--consequences of damming. Aquat. Sci., 64: 55–65.
G.O.K. 1980. Nairobi/Y503 Edition 5-SK, Survey of Kenya Nairobi, , Kenya
G.O.K. 2001. National Biodiversity Strategy and Action Plan Nairobi, , Kenya
Gasse, F., ed. 1986. East African Diatoms: Taxonomy, Berlin, Stuttgart, , Germany: Ecological Distribution.
Germain, H. 1981. Flore Diatomées, Paris: Boubée.
Gitonga, J. K. 1992. “Agricultural chemicals and wetlands: a review.”. In Wetlands of Kenya. Proceedings of the KWWG Seminar on wetlands of Kenya, Edited by: Crafter, S. A., Njuguna, S. G. and Howard, G. W. Nairobi, , Kenya: National Museums of Kenya.
HABITAT (United Nations Centre for Human Settlements). 1997. Human settlements basic statistics Nairobi, , Kenya
Hach Company. 1996. DA/2000 Spectrophotometer Procedures Manual, Colorado, , USA: Loveland.
Hendey, N. I. 1974. The Permanganate method for cleaning freshly gathered diatoms. Microscopy, 32: 423–426.
Hillebrand, H. and Sommer, U. 2000. Diversity of benthic microalgae in response to colonization time and eutrophication. Aquat. Bot., 67: 221–236.
Huangi, G. H. and Xia, J. 2001. Barrier to sustainable water-quality management. J. Environ. Manage., 61: 1–23.
Jefrries, M. and Mills, D. 1990. Freshwater Ecology: Principles and Application, London and New York: Belhaven Press.
Kelly, M. 2000. Identification of common diatom in rivers. Field Studies, 9: 583–700.
Kelly, M. G., Cazaubon, A., Coring, E., Dell'Uomo, A., Ector, L., Goldsmith, B., Guasch, H., Holimann, J., Jarman, A., Kawecka, B., Kwandrans, J., Laugaste, R., Lindstram, E.-A., Leitao, M., Marvan, P., Padisák, J., Pipp, E., Prygiel, J., Rott, E., Sabater, S., van Dam, H. and Vizinet, J. 1998. Recommendations for the routine sampling of diatoms for water quality assessments in Europe. J. Appl. Phycol., 10: 215–224.
Kinyua, A. M. and Pacini, N. 1991. The impact of pollution on the ecology of the Nairobi-Athi River system in Kenya. J. Biochem. Phys., 1(1): 5–7.
Kneale, P. E. and Howard, A. 1997. Statistical analysis of algal and water quality. Hydrobiologia, 349: 59–63.
Köster, D. and Hübener, T. 2001. Application of diatom indices in a planted ditch constructed for tertiary sewage treatment in Schwaan, Germany. Internat. Rev. Hydrobiol., 86: 241–252.
Krammer, K. and Lange-Bertalot, H. 1986-1991. “Bacillariophyceae 1. Teil: Naviculaceace; 2. Teil: Bacillariophyceae, Epithemiaceae, Surirellaceae Bacillariophyceae; 3. Teil: Centrales, Fragilariaceae, Eunotiaceae; 4. Teil: Achnanthaceae, Naviculaceace, Gomphonema”. In Susswasserflora von Mitteleuropa, Edited by: Ettl, H., Gerloff, J., Heynig, H. and Mollenhauer, D. Stuttgart: Gustav Fischer-Verlag.
Leland, H. V. and Porter, S. D. 2000. Distribution of benthic algae in the upper Illinois River basin in relation to geology and land use. Freshwat. Biol., 44: 279–301.
Lobo, E. A., Katoh, K. and Aruga, Y. 1995. Response of epilithic diatom assemblages to water pollution in rivers in the Tokyo Metropolitan area, Japan. Freshwat. Biol., 34: 191–204.
Lowe, R. L., Guckert, J. B., Belanger, S. E., Davidson, D. H. and Johnson, D. W. 1996. An evaluation of periphyton community structure and function on tile and cobble substrata in experimental stream mesocosms. Hydrobiologia, 328: 135–146.
Lowe, R. L. and Pan, Y. 1996. “Benthic algal communities as biological indicators.”. In Algal Ecology, Freshwater Benthic Ecosystems, Edited by: Stevenson, R. J., Bothwell, M. L. and Lowe, R. L. 705–740. California: Academic Press.
McCormick, P. V. and Stevenson, R. J. 1998. Periphyton as tool for ecological assessment and management in the Florida Everglades. J. Phycol., 34: 726–733.
Muylaert, K., Kerckvoorde, A., Vyverman, K. and Sabbe, K. 1997. Structural characteristics of phytoplankton assemblages in tidal and non-tidal freshwater systems: a case study from the Scheide Basin, Belgium. Freshwat. Biol., 38: 263–276.
NEAP (National Environment Action Plan). 1994. The Kenya Environment Action Plan, Nairobi, , Kenya: Ministry of Environment and Natural Resources.
O'Farrell, I., Vinocur, A. and Izaguirre, I. 1996. Phytoplankton ecology of the lower Paraná River (Argentina). Arch. Hydrobiol. Suppl., 115: 75–89.
Odera, D. R., Semu, E. and Kamau, G. N. 2000. Assessment of cottage industry derived heavy metal pollution of soils with Ngara and Gikomba Areas of Nairobi City, Kenya. African J. Sci. Technol., 1(2): 52–62.
Pan, Y., Stevenson, R. J., Hill, B. H., Herlihy, A. T. and Collins, G. B. 1996. Using diatoms as indicators of ecological conditions in lotie systems: A regional assessment. J. N. A. Benthol. Soc., 15: 481–495.
Patil, G. P. and Myerst, W. L. 1999. Environmental and Ecological health assessment of landscapes and watersheds with remote sensing data. Ecosyst. Health, 5(4): 221–224.
Raschke, R. L. 1993. Diatom (Bacillariophyta) community response to phosphorus in Everglades National Park, USA. Phycologia, 32: 48–58.
Rothhaupt, K. O. 2000. Plankton population dynamics: food web interactions and abiotic constraints. Freshwat. Biol., 45: 105–109.
Sims, P. A., Barber, H. G., Carter, J. R. and Hartley, B. 1996. Atlas of British Diatoms, England: Biopress.
Soltan, M. E. and AIi, M. M. 1996. The impact of three industrial effluents on submerged aquatic plants in the River Nile, Egypt. Hydrobiologia, 340: 77–83.
Sonneman, J. A., Walsh, C. J., Breen, P. E. and Sharpe, A. K. 2001. Effects of urbanisation on streams of the Melbourne region, Victoria. 11. Benthic diatom communities. Freshwat. Biol., 46: 553–565.
StatSoft, Inc. 1995. STATISTICA for Windows Tulsa, OK, , USA
Stevenson, R. J., Bothwell, M. L. and Lowe, R. L., eds. 1996. Algal Ecology: Freshwater Benthic Ecosystems, California: Academic Press.
Stevenson, R. J. and Pan, Y. 1999. “Assessing environmental conditions in rivers and streams with diatoms.”. In The Diatoms: Applications for the Environmental and Earth Sciences, Edited by: Stoermer, E. and Smol, J. P. 11–41. UK: Cambridge University Press.
Stoermer, E. and Smol, J. P., eds. 1999. The Diatoms: Applications for the Environmental and Earth Sciences, UK: Cambridge University Press.
ter Break, C. J. E. 1990. Updates Notes: CANOCO v. 3.1., Wageningen, , The Netherlands: Agricultural Mathematics Group.
Twinch, A. J. and Breen, C. M. 1982. A comparison of nutrient availability measured by chemical analysis and calculated from bioassay yields. Hydrobiologia, 94: 247–255.
UNEP (United Nations Environment Programme). 2001. The Nairobi River Project (ROA) Nairobi, , Kenya
van Dam, H., Mertens, A. and Sinkeldam, J. 1994. A coded checklist and ecological values of freshwater diatoms from Netherlands. Neth. J. Aquat. Ecol., 28(1): 117–133.
Whitton, B. A. and Kelly, M. G. 1995. Use of algae and other plants for monitoring rivers. Australian J. Ecol., 20: 45–56.
Whitton, B. A. and Rott, E., eds. Proceedings of an International Symposium on Use of Algae for Monitoring Rivers. Sept. 17-19 1995. Innsbruck, , Austria: Austrian Ministry of Science, Traffic and Arts.
Wood, E. D., Armstrong, F. A. J. and Richards, F. A. 1967. Determination of nitrates in seawater by cadmium-copper reduction to nitrate. J. Mar. Biol., 47: 23–30.
Published
Issue
Section
License
Manuscripts must be original. They must not be published or be under consideration for publication elsewhere, in whole or in part. It is required that the lead author of accepted papers complete and sign the MSU Press AEHM Author Publishing Agreement and provide it to the publisher upon acceptance.
