Spatial Response of Epilithic Diatom Communities to Downstream Nutrient Increases

• Published in: Water environment research Vol. 87; no. 6; pp. 547 - 558
• Main Authors: Schuch, Marilia, Oliveira, Maria Angelica, Lobo, Eduardo A.
• Format: Journal Article
• Language: English
• Published: United States THE WATER ENVIRONMENT FEDERATION 01-06-2015; Water Environment Federation; Blackwell Publishing Ltd
• Subjects: Algae; Brazil; Community composition; Diatoms - physiology; Dissolved oxygen; Downstream; Environmental Monitoring; epilithic diatoms; Eutrophication; Nutrients; organic pollution; River basins; Rivers; Rivers - chemistry; Seasons; subtropical temperate basin (Brazil); Total dissolved solids; Turbidity; Water monitoring; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - pharmacology; Water pollution; Water quality; Water quality management; Brazil; Sao Paulo Brazil
• ISSN: 1061-4303; 1554-7531
• DOI: 10.2175/106143014X14062131178196

To monitor water quality and investigate relationships between downstream nutrient increases and diatom communities in the Pardo River Basin, Brazil, water and diatom samples were collected between 2005 and 2009. There were significant differences in diatom community composition among all river zones, with the greatest differences found between the upper and lower reaches. Significant changes were detected in relative abundances of diatom species and spatial structuring was evident. Dissolved oxygen, phosphates, turbidity, Eicherichia coli, and total dissolved solids were the most important variables shaping diatom communities, characterizing an organic pollution and eutrophication gradient. However, the hypothesis of sensitive species prevailing upstream and their gradual downstream replacement for more tolerant species was not confirmed because shifts in relative abundances of the same group of species in both the upper and lower reaches of the rivers were identified.