Estuarine phytoplankton group-specific responses to sublethal concentrations of the agricultural herbicide, atrazine

Date

2002 Oct

Authors

Pinckney JL
Ornolfsdottir EB
Lumsden SE

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Abstract

Atrazine is a common agricultural herbicide that is readily transported into estuaries through surface water runoff. In this study, we determined the short-term (24-48 h) sublethal effects of atrazine on estuarine phytoplankton biomass and community composition. Phytoplankton group-specific responses to atrazine exposure (25 mug l(-1)) were measured using natural water samples collected from two locations in Galveston Bay, Texas. Addition bioassays, coupled with HPLC pigment analysis, were used to quantify changes in the relative abundances of algal groups. For all algal groups except prasinophytes, the addition of atrazine in combination with nitrate was not significantly different from nitrate additions alone. These results suggest no significant negative effect of atrazine on phytoplankton under the specified environmental conditions for the bioassays. Although low concentrations of atrazine may have minimal impacts on phytoplankton, herbicide loadings need to be further characterized before generalizations can be applied to estuarine and coastal ecosystems. (C) 2002 Elsevier Science Ltd. All rights reserved

Description

1109-1116

Keywords

atrazine, TEXAS, PHYTOPLANKTON, ESTUARY, Gulf of Mexico, nutrient, agriculture, herbicide, POTAMOGETON-PERFOLIATUS L, MARINE-PHYTOPLANKTON, Mississippi River, RISK ASSESSMENT, GALVESTON-BAY, community, PIGMENTS, ALGAE, MACROPHYTES, ENVIRONMENT

Citation