Report on Harmonisation of freshwater biological methods
Report on Harmonisation of freshwater biological methods
Report on Harmonisation of freshwater biological methods
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BIOLOGICAL QUALITY ELEMENT: PHYTOPLANKTON26. Most countries include in their <strong>biological</strong> m<strong>on</strong>itoring systems some metric forphytoplankt<strong>on</strong>. The lowest number <strong>of</strong> lakes for which phytoplankt<strong>on</strong> is m<strong>on</strong>itored isin the NO GIG (54%), in all other GIGs at least 60% <strong>of</strong> the lakes are m<strong>on</strong>itored forphytoplankt<strong>on</strong>. However, there is great heterogeneity both within GIG and betweenGIGs in terms <strong>of</strong> the sampling and metrics estimated.27. The most frequent sampling method in all the GIGs involves the collecti<strong>on</strong> <strong>of</strong>surface samples between 2 and 12 times per year (spring and summer) at <strong>on</strong>e stati<strong>on</strong>.28. The metrics used in the assessment differ both within and am<strong>on</strong>g GIGs, but mostcountries measure abundance and biomass and successively less countries record alsobloom occurrence, size compositi<strong>on</strong> and primary productivity. There are no countriesthat completely fulfill the WFD metric requirements.BIOLOGICAL QUALITY ELEMENT: PHYTOBENTHOS29. Most countries do not use phytobenthos in their <strong>biological</strong> m<strong>on</strong>itoring. Thehighest number <strong>of</strong> lakes m<strong>on</strong>itored for phytobenthos is found in the EC GIG followedclosely by CE and AL GIGs, while in the NO GIG countries this <strong>biological</strong> element isnot used at all at intercalibrati<strong>on</strong> sites. Like for other elements, there is greatheterogeneity both within GIG and between GIGs in terms <strong>of</strong> the sampling andmetrics estimated.30. In cases where phytobenthos is sampled, the most frequent sampling frequency isbetween 2 and 6 times per year, and the number <strong>of</strong> sampling stati<strong>on</strong>s in each lake varyin the GIGs from <strong>on</strong>e lake stati<strong>on</strong> (all lakes in the AT and EC GIGs), 2-10 stati<strong>on</strong>s(most lakes in the BA and CE GIGs), or more than 10 stati<strong>on</strong>s (all lakes in the MEGIG and most in the AL GIG).31. As with chlorophyll a and phytoplankt<strong>on</strong>, sampling is held during the vegetati<strong>on</strong>growth period, spring and summer. The habitats sampled differ, some countriessample epilithic and others epiphytic phytobenthos. The compositi<strong>on</strong> metrics arespecies compositi<strong>on</strong>, presence or absence <strong>of</strong> species and indicator taxa. The quantitymetrics are the relative abundance <strong>of</strong> species, indicator taxa and excessive growth <strong>of</strong>nuisance species such as Cladophora. Most countries include in their assessment both11