Impact of atypical ammonium concentrations on phytoplankton abundance and composition in fresh versus estuarine waters

Aquatic Biology

Gry Mine Berg¹  Douglas J. Craig¹  Mary Lou Esparza¹  Curt Swanson¹  Ann E. Farrell¹  Bhupinder S. Dhaliwal¹ 

关键词: Phytoplankton;    Ammonium;    N:P ratio;    NH4+:NO3- ratio;    Diatoms;    Chlorophytes;    San Francisco Estuary;    Suisun Bay;   

DOI  :  10.3354/ab00588

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The impact of atypically high ammonium (NH₄⁺) concentrations delivered via treated wastewater effluent on phytoplankton community composition was investigated in a tidal slough connected with Suisun Bay in the northern part of San Francisco Bay. Input of effluent to a downstream location resulted in NH₄⁺ concentrations of (mean ± SD) 1021 ± 380 µmol l^-1, compared with 2.9 ± 1 µmol l^-1 at a site further upstream, and 4.8 ± 1 µmol l^-1 in Suisun Bay. Comparison of the diatom community at the downstream site in Pacheco Slough with that in Suisun Bay revealed a substantial overlap in species, including Cyclotella scaldensis, which dominated diatom species composition in both locations. The ratio of diatoms:other phytoplankton biomass (µmol³:µmol³) suggested that diatoms contributed a greater proportion of total phytoplankton community biomass at the downstream location (48.6 ± 87) versus in Suisun Bay (9.5 ± 1) or upstream (9.5 ± 8), and that diatoms can readily grow in the presence of NH₄⁺ concentrations varying from 2 to 1350 µmol l^-1. In the present investigation, species composition of the seeding population was found to be a more important predictor of final phytoplankton community composition than nutrient concentrations or ratios.

【 授权许可】

Unknown