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Spatial Response of Epilithic Diatom Communities to Downstream Nutrient Increases
Author(s) -
Schuch Marilia,
Oliveira Maria Angelica,
Lobo Eduardo A.
Publication year - 2015
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143014x14062131178196
Subject(s) - diatom , eutrophication , environmental science , nutrient , water quality , turbidity , ecology , hydrology (agriculture) , biology , geology , geotechnical engineering
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.