Integrating seasonal information on nutrients and benthic algal biomass into stream water quality monitoring

Journal of the American Water Resources Association
By:  and 

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Abstract

Benthic chlorophyll a (BChl a) and environmental factors that influence algal biomass were measured monthly from February through October in 22 streams from three agricultural regions of the United States. At-site maximum BChl a ranged from 14 to 406 mg/m2 and generally varied with dissolved inorganic nitrogen (DIN): 8 out of 9 sites with at-site median DIN >0.5 mg/L had maximum BChl a >100 mg/m2. BChl aaccrued and persisted at levels within 50% of at-site maximum for only one to three months. No dominant seasonal pattern for algal biomass accrual was observed in any region. A linear model with DIN, water surface gradient, and velocity accounted for most of the cross-site variation in maximum chlorophyll a(adjusted R2 = 0.7), but was no better than a single value of DIN = 0.5 mg/L for distinguishing between low and high-biomass sites. Studies of nutrient enrichment require multiple samples to estimate algal biomass with sufficient precision given the magnitude of temporal variability of algal biomass. An effective strategy for regional stream assessment of nutrient enrichment could be based on a relation between maximum BChl a and DIN based on repeat sampling at sites selected to represent a gradient in nutrients and application of the relation to a larger number of sites with synoptic nutrient information.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Integrating seasonal information on nutrients and benthic algal biomass into stream water quality monitoring
Series title Journal of the American Water Resources Association
DOI 10.1111/1752-1688.12451
Volume 52
Issue 5
Year Published 2016
Language English
Publisher Wiley
Contributing office(s) Washington Water Science Center
Description 15 p.
First page 1223
Last page 1237