1 / 17

Sources of variability in phytobenthos biomass measurements using the BenthoFluor

Sources of variability in phytobenthos biomass measurements using the BenthoFluor. Corina Carpentier AquaLife Workshop, Kiel, Germany 2 nd June 2010. Introduction. Why phytobenthos analysis in rivers? Why in situ phytobenthos measurements? Sources of variability substrate

sakina
Download Presentation

Sources of variability in phytobenthos biomass measurements using the BenthoFluor

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Sources of variability in phytobenthos biomass measurements using the BenthoFluor Corina Carpentier AquaLife Workshop, Kiel, Germany 2nd June 2010

  2. Introduction • Why phytobenthos analysis in rivers? • Why in situ phytobenthos measurements? • Sources of variability • substrate • patchy distribution • representativeness of results

  3. European Water Framework Directive (WFD) HIGH { GOOD Low { MODERATE Moderate No deterioration { POOR High Restoration { BAD Severe Impact Ecological Status { None or minimal Links between chemical and ecological status? Courtesy Peter Pollard, Scottish Environment Protection Agency

  4. Implementation of the WFD

  5. Research objective • Development of a method for the assessment of phytobenthos biomass as an indicator for the trophic status of flowing waters • This method has to be: • sufficiently sensitive for trophic status assessment • practical • fast • cheap

  6. CEN Guidance Standards EN 13946 and 14407: removal efficiency of sampling procedure?

  7. Avoid sampling errors by performingin situ measurements • BenthoFluor measurements in the field: • many measurements in a short time • determine suitable spots for biodiversity sampling • major difference as compared to phytoplankton analysis: the presence of a substrate

  8. The influence of the substrate

  9. Substrate-dependent correction factor

  10. Reflection factor based on 700 nm value yi = bixi (1+baixi) yi = real value at wavelength i; xi = raw value at wavelength i; ai = wavelength-dependent empirical factor; b = factor expressing the reflection properties of the substrate(b = 1 for stone; b = 2.1 for black background)

  11. Patchy distribution Hildebrandia rivularis

  12. Patchiness (2)

  13. CEN Guidance Standards EN 13946 and 14407: 5 samples per site left bank right bank Danube River, Bratislava (SK)

  14. How many measurements? 1.46 0.41 0.26

  15. Danube River data: 2,477 measurements n = 33 Width of 95% CI: 0.5  reached after 33 measurements

  16. In conclusion Substrate-dependent correction factor improves results considerably In situ BenthoFluor measurements provide insight into patchy distribution of phytobenthos Limited number of measurements (25-35) provides statistically representative results in little time (appr. 10-15 minutes)

  17. Thank you for your attention! Corina Carpentier AquaLife Workshop, Kiel, Germany 2nd June 2010

More Related