|Opdracht met betrekking tot het uitvoeren van de kaderrichtlijn water: fytoplankton monitoring van de Belgische kust voor rekening van FOD volksgezondheid, veiligheid van de voedselketen en leefmilieu|
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Reference no: MM/WB/KRW-003
Acronym: KRW FYTO 2007
Period: November 2007 till October 2008
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- Universiteit Gent; Laboratorium voor Protistologie en Aquatische Ecologie (PAE), more, organiser
- Federale overheidsdienst Volksgezondheid, Veiligheid van de Voedselketen en Leefmilieu; Directoraat generaal Leefmilieu; Dienst Marien Milieu, more, sponsor
|The here executed phytoplankton biomonitoring of the Belgian continental zone was performed in the light of the European Water Framework Directive (WFD), which aim to achieve a good ecological status, concerning chemical and ecological parameters, by 2015 for all inland and coastal surface waters within defined river basin districts. To achieve a good ecological states, only slight deviations from an antropogenic undisturbed condition are allowed. To decide if the goals are met or not, each member state should develop an assessment method on the base of specified ecological quality elements (a.o. phytoplankton). The comparison of the boundaries values between the different quality classes from the assessment systems for neighboring countries is carried out in so called Geographic Intercalibration Groups. These GIG’s contain member states with comparable types of water bodies in so-called ecoregions. Intercalibration should then lead to the setting of consistent and comparable standards for rivers, lakes and coasts across Europe.
Within the intercalibration process for the quality element phytoplankton from the North Sea, all MS have agreed to use chlorophyll-a as a metric for biomass, while many memberstates use the colonial Haptophyte Phaeocystis as a negative indicator, linked with eutrophication.
In Belgium, chlorophyll a and the amount of Phaeocystis-cells are two tools used in the phytoplankton assessment method for the Belgian Continental Shelf (BCS). Eutrophication in the BCS occurs in the form of massive, ephemeral Phaeocystis-colony blooms during spring (April-May). Analysis of historical data (ASMO 98/3/Info.1-F) suggests that foam accumulation would occur from a Phaeocystis cell concentration of 107 l-1. This cell concentration can be converted into a Chl-a concentration of 0.5 μg Chl-a l-1 (C:Chl a = 29) using the experimentally determined factor of 0.5 pg Chl-a /Phaeocystis cell (Rousseau et al., 1990).
Continental shelf seasonal evolution of Chl-a concentrations measured on a weekly basis, indicates that the average Chl-a concentration of 9.2 μg l-1 corresponds to the Phaeocystis pre-bloom situation, itself determined as a Phaeocystis concentration higher than 1x106 cells l-1 (Cadée & Hegeman, 1991).