Response of phytoplankton to protective-restoration treatments enhancing water quality in a shallow urban lake.

Elżbieta Zębek,Agnieszka Napiórkowska-Krzebietke

doi:10.1007/s10661-016-5633-4

Abstract

Lake Jeziorak Mały is a shallow urban lake where storm water pretreatment separators and a fountain-based water aeration system were installed as protective-restoration measures to enhance water quality. We investigated the effect of these procedures on phytoplankton dynamics and physicochemical properties in the littoral and pelagial zones in 1996–2003, 2005, and 2013. A decrease in cyanobacteria proportion, abundance, and biomass has been noticed, and other phytoplankton groups increased after these procedures. Significantly elevated species diversity was recorded in the littoral zone with the exchange of cyanobacteria and diatom dominant species typically induced by alteration from hypertrophic to eutrophic status. For example, the polytrophic Limnothrix redekei was replaced by eutrophic Planktolyngbya brevicellularis. This stemmed from greater oxygenation, water visibility and diminished pH, conductivity, and orthophosphates. Our results showed that introducing these restoration measures influence on the long-term succession of phytoplankton and induced the change from a polytrophic to eutrophic state, and that such measures are vitally important in future considerations of shallow urban lake management.

Highlights

Intensified urban industrial development contribute to water eutrophication (Bernhardt 1987; Reynolds 2003), which accelerates in urban agglomerations when domestic sewage and nutrient-rich stormwater enter shallow lakes (Guzkowska and Gasse 1990; Wichelen et al 2007)
In order to protect waters of urban lakes, separators are used for storm water pretreatment from polycyclic aromatic hydrocarbons (PAHs)
The purpose of this study was to determine the response of phytoplankton related to physicochemical properties to these restorative procedures in urban Lake Jeziorak Mały in1996–2003, 2005, and 2013

Summary

Introduction

Intensified urban industrial development contribute to water eutrophication (Bernhardt 1987; Reynolds 2003), which accelerates in urban agglomerations when domestic sewage and nutrient-rich stormwater enter shallow lakes (Guzkowska and Gasse 1990; Wichelen et al 2007). Excess primary production causes massive growth of some algal species, cyanobacteria, resulting in algal blooms and deterioration in water quality (Reynolds 1978; Spodniewska 1986; Bucka 1989; Napiórkowska-Krzebietke 2015; Napiórkowska-Krzebietke and Dunalska 2015; Napiórkowska-Krzebietke et al 2015) These processes are effectively limited by reducing nutrient inflow, especially that of phosphorus, using lake-basin restoration methods (Bernhardt 1987; Reynolds 2003), including external protective methods in the lake’s catchment area (Lossow 1998; Dunalska et al 2015), it is quite difficult to establish the most suitable and permanently effective restoration methods for individual lakes. In order to protect waters of urban lakes, separators are used for storm water pretreatment from polycyclic aromatic hydrocarbons (PAHs)

Objectives

Methods

Results

Discussion

Conclusion