Phytoplankton-Online Interactive regulation of phytoplankton succession by physical forcing and internal phosphorus loading: A comparative study in eutrophic freshwater lakes from different climatic regimes
Country: EU Projects
Start Date:           Duration: 54 months         Project Type: RTD
Contract Number: EVK1-CT-1999-00037
Organisation Type:  EC Project
Topics: 
Water and sanitation-->Water and sanitation Overview
Water resources and their management -->Stresses, quality and ecological status
Project objectives: 
After becoming aware of phosphorus (P) as the driving force of eutrophication the reduction of external P loading became the primary management target.   However, 
in many cases even a drastic reduction of the external P-loading did not succeed in improving water quality since P-recycling from the large pool of sedimentary 
phosphorus that had accumulated over the years sufficed to provide the amount of  bio-available P necessary to support algal blooms. The question arises in 
how far this development can be reversed and algal diversity restored. Considering the variety of available remedial measures, an experimental procedure 
to predict water quality changes is needed to arrive at the decision upon the optimum management strategy. The proposed study complies with this requirement 
through an experimental approach based upon the control of environmental parameters such as nutrient loading or resuspension in large enclosures, while 
monitoring phytoplankton succession.    
   
The central part of our approach is the Delayed Fluorescent Excitation Spectrometer (DF). This device is capable to measure active chlorophyll over a wide 
linear range while at the same time distinguishing between major phytoplankton groups.  One objective of this study is to introduce the DF as an on-line monitoring 
tool for phytoplankton succession in freshwater lakes or reservoirs.   
   
Using the same strategy, i.e. large enclosures and DF monitoring of phytoplankton density composition and activity under known (controlled) conditions 
of internal P loading, we shall study in parallel in Lake's Balaton, Kinneret and Erken. We intend to elucidate the extent and the timing of phytoplankton response 
to a range of imposed changes and to analyze the resulting data sets based upon the modeling expertise of the work groups involved in this project.
Project Summary: 
Deterioration of water quality of freshwater lakes; as a consequence of man-made perturbations such as water level regulations, pollution and food web manipulations 
is a commonly observed phenomenon of our times. In the extreme case of long lasting elevated pollution loads and the affluence of bio-available phosphorus 
(BAP) the lake ecosystem responded with increasing algal biomass and a species shift to nitrogen fixing cyanobacteria. After becoming aware of phosphorus 
(P) as the driving force of eutrophication the reduction of external P loading became the primary management target. However, in many cases even a drastic reduction 
of the external P-loading did not succeed in improving water quality since P- recycling from bottom sediments sufficed to provide the amount of BAP necessary 
to support algae blooms.    
   
The question arises in how far this development can be reversed and algae diversity restored. Considering the variety of available remedial measures, an 
experimental procedure to predict water quality changes is needed to arrive at the decision upon the optimum management strategy. The proposed study complies 
with this requirement through an experimental approach based upon the control of environmental parameters such as nutrient loading or resuspension in large 
enclosures, while monitoring phytoplankton succession. Our proposal enforces community water policy aimed to achieve sustainability of aquatic systems 
by responding to the following Water Framework Directives: eutrophication control (91/271/EEC) and safeguarding human health by establishing strict standards 
for the quality of water intended for human consumption (80/778/EEC).
Achieved Objectives: 
Delayed Fluorescent Excitation Spectrometer (DF) was successfully applied at several field sites (Lake Balaton, Lake Erken. DF spectroscopy revealed fast 
changes in the biomass of phytoplankton that could not be seen from weekly chlorophyll measurements with extraction in acetone.
Product Descriptions: 
not public available
Additional Information:
Project Resources:
Weblink:
http://phyto-online.ocean.org.il/
Funding Programme(s): 
EC Framework Programme 5
Link to Organisations:
Submitted by: EUGRIS Team Dr Stefan Gödeke  Who does what?  22/02/2005 10:48:00
Updated by: EUGRIS Team Professor Paul Bardos  Who does what?  03/10/2006 14:19:00