The sampling and preparation of algae Maria Kahlert

Sampling of diatoms Different approaches: –Most common: Use of benthic diatoms for routine monitoring of streams EU standard for sampling: EN (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

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 prEN Water quality - Guidance standard for the surveying, sampling and laboratory analysis of phytobenthos in shallow running water. Under Approval Nordic standard (Jarlman, Lindstrøm, Eloranta & Bengtsson 1996) National methods (check for example the Austrian, German and Norwegian methods)

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)

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% %

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

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.

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

The preparation of algae Diatoms: Detailed method (A. Jarlman) following EU standard: EN (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)

References EN (2003). Water quality - Guidance standard for the routine sampling and pretreatment of benthic diatoms from rivers EN (2005). Water quality - Guidance standard for the identification, enumeration and interpretation of benthic diatom samples from running waters prEN Water quality - Guidance standard for the surveying, sampling and laboratory analysis of phytobenthos in shallow running water. Under Approval 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 Kahlert, M. & Pettersson, K. (2002): The impact of substrate and lake trophy on the biomass and nutrient status of benthic algae. – Hydrobiologia 489: 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): Stevenson, R.J. 1984: Procedures for mounting algae in syrup medium. Transactions of the American Microscopical Society 103: