Seasonality and controls of phytoplankton productivity in the middle Cape Fear River, USA

Autor: Stephen C. Whalen, J. T. Kennedy
Rok vydání: 2007
Předmět:
Zdroj: Hydrobiologia. 598:203-217
ISSN: 1573-5117
0018-8158
DOI: 10.1007/s10750-007-9151-9
Popis: Our 1 year study was aimed at assessing seasonal patterns and controls on phytoplankton primary production (PPR) and biomass (chlorophyll a) in a fourth order section of the middle Cape Fear River in North Carolina, USA, and to determine the impact of three low-head lock and dam (LD) structures on these variables within the 70 km study reach of this coastal river. Mean concentrations of NO3 −–N, NH4 +–N and soluble reactive phosphorus (SRP) averaged 52.9, 6.0, and 3.6 μmol l−1 in monthly sampling, while the average light attenuation coefficient was 2.4 m−1. The average euphotic depth was 2.1 m. Nutrient concentrations and attenuation coefficients were not significantly different above versus below each LD, or along the entire study reach. Significantly higher concentrations of dissolved O2 below versus above each LD were attributed to re-aeration during spillway transit. No seasonal pattern in physicochemical properties was apparent. Phytoplankton chlorophyll a concentrations ranged from
Databáze: OpenAIRE
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