Transcript Diatoms as Bioindicators of Water Quality

Diatoms as Bioindicators of
Water Quality
Cassandra Messina
April 19, 2005
ECOL 475
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
Pennate Diatoms
Bilateral symmetry
Two large, platelike
plastids
Raphid pennates
Araphid pennates
Centric Diatoms
Cylindrical cells
Radial symmetry
Many plastids
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
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
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
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): 20652085.
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.