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Sampling of diatoms. Different approaches:Most common: Use of benthic diatoms for routine monitoring of streams EU standard for sampling: EN 13946 (2003). Water quality - Guidance standard for the routine sampling and pretreatment of benthic diatoms from riversNational standards for the bioindices and class boundariesUse of diatoms for lakes under way.
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1. The sampling and preparation of algae Maria Kahlert
2. Sampling of diatoms Different approaches:
Most common: Use of benthic diatoms for routine monitoring of streams
EU standard for sampling:EN 13946 (2003). Water quality - Guidance standard for the routine sampling and pretreatment of benthic diatoms from rivers
National standards for the bioindices and class boundaries
Use of diatoms for lakes under way
3. Sampling of other algae Investigation of the total benthic algal community
Approach to EU standardize even non-diatom sampling to reach all goals of the WFD 00230228 prEN 15708 Water quality - Guidance standard for the surveying, sampling and laboratory analysis of phytobenthos in shallow running water. Under Approval 2009-05
Nordic standard (Jarlman, Lindstrøm, Eloranta & Bengtsson 1996)
National methods (check for example the Austrian, German and Norwegian methods)
4. Sampling of other algae Different approaches:
Quantitative sampling
hard substrate: brush samplers (e.g. Peters et al. 2005)
macrophytes: copy of macrophytes, image analysing (e.g. Kahlert 2000), sampling in tubes
Transect methods
estimation of percentage cover within a frame (e.g. NO)
By eye
With camera and picture analysis
Semi-quantitative (e.g. Nordic standard)
5. Sampling of all algae Nordic standard – analysis of macroscopic and microscopic communities
Macroscopic communities:
Screening of river bed, estimation of percentage cover of different communities by eye, qualitative sampling of all different communities, verification in laboratory
Percentage cover:
< 5%
5-10%
10-20%
20-50%
50-100%
6. Sampling of all algae Nordic standard – analysis of macroscopic and microscopic communities
Microscopic communities:
Qualitative sampling of stones if present, otherwise other dominating substrates, analysis in laboratory
Semiquantitative estimation:
1 = rare occurrence
2 = moderate occurrence
3 = common occurrence
4 = abundant occurrence
5 = very abundant occurrence
7. Sampling of all algae Investigation of the total benthic algal community Idea: to know the whole community and biomass will give a better picture of the ecological status of a stream or lake than only an analysis of the relative abundance of diatoms. For example, grazers are dependent on a certain biomass and algal composition to survive.
8. Sampling of all algae Investigation of the total benthic algal community
However, this analysis is very time consuming, extremely difficult to standardize, and has a high error when used for biomonitoring
With time, there will be more experience, even methods and indices will get better probably with an increased use
9. The preparation of algae
Diatoms: Detailed method (A. Jarlman) following EU standard: EN 14407 (2005). Water quality - Guidance standard for the identification, enumeration and interpretation of benthic diatom samples from running waters
Soft algae: Modified method following R.J. Stevenson (1984)
10. References EN 13946 (2003). Water quality - Guidance standard for the routine sampling and pretreatment of benthic diatoms from rivers
EN 14407 (2005). Water quality - Guidance standard for the identification, enumeration and interpretation of benthic diatom samples from running waters
00230228 prEN 15708 Water quality - Guidance standard for the surveying, sampling and laboratory analysis of phytobenthos in shallow running water. Under Approval 2009-05
Jarlman, A., Lindstrøm, E.-A., Eloranta, P. & Bengtsson, R. (1996). Nordic standard for assessment of environmental quality in running water. In: Whitton, B.A. & Rott, E. (eds), Use of algae for monitoring rivers II, p. 17-28.
Kahlert, M. & Pettersson, K. (2002): The impact of substrate and lake trophy on the biomass and nutrient status of benthic algae. – Hydrobiologia 489: 161-169.
Peters, L., Schleifhacken, N., Kahlert, M. & Rothaupt, K.-O. (2005): An efficient in situ method for sampling periphyton in lakes and streams. – Arch. Hydrobiol. 163 (1): 133-141.
Stevenson, R.J. 1984: Procedures for mounting algae in syrup medium. Transactions of the American Microscopical Society 103:320-321.