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Efficacy of algal metrics for assessing nutrient and organic enrichment in flowing waters

Freshwater Biology

By:
, , , , and
DOI: 10.1111/j.1365-2427.2007.01951.x

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Abstract

1. Algal-community metrics were calculated for periphyton samples collected from 976 streams and rivers by the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Programme during 1993-2001 to evaluate national and regional relations with water chemistry and to compare whether algal-metric values differ significantly among undeveloped and developed land-use classifications. 2. Algal metrics with significant positive correlations with nutrient concentrations included indicators of trophic condition, organic enrichment, salinity, motility and taxa richness. The relative abundance of nitrogen-fixing algae was negatively correlated with nitrogen concentrations, and the abundance of diatom species associated with high dissolved oxygen concentrations was negatively correlated with both nitrogen and phosphorus concentrations. Median algal-metric values and nutrient concentrations were significantly lower at undeveloped sites than those draining agricultural or urban catchments. 3. Total algal biovolume did not differ significantly among major river catchments or land-use classifications, and was only weakly correlated with nitrate (positive) and suspended-sediment (negative) concentrations. Estimates of periphyton chlorophyll a indicated an oligotrophic-mesotrophic boundary of about 21 mg m-2 and a mesotrophic-eutrophic boundary of about 55 mg m-2 based on upper and lower quartiles of the biovolume data distribution. 4. Although algal species tolerance to nutrient and organic enrichment is well documented, additional taxonomic and autecological research on sensitive, endemic algal species would further enhance water-quality assessments. ?? 2007 Blackwell Publishing Ltd.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Efficacy of algal metrics for assessing nutrient and organic enrichment in flowing waters
Series title:
Freshwater Biology
DOI:
10.1111/j.1365-2427.2007.01951.x
Volume
53
Issue:
5
Year Published:
2008
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Freshwater Biology
First page:
1036
Last page:
1054
Number of Pages:
19