- Fifty shades of grey: Variability in metric-based assessment of surface waters using macroinvertebrates
- Award date
- 22 January 2014
- Number of pages
- Document type
- PhD thesis
- Faculty of Science (FNWI)
- Institute for Biodiversity and Ecosystem Dynamics (IBED)
Since the introduction of the European Water Framework Directive (WFD) in 2000, every member state is obligated to assess the effects of human activities on the ecological quality status of all water bodies and to indicate the level of confidence and precision of the results provided by the monitoring programs in their river basin management plans (European Commission, 2000). Currently, the statistical properties associated with aquatic monitoring programs are often unknown. Therefore, the overall objective of this dissertation is to quantify the variability and accuracy associated with biological assessment based on macroinvertebrates. This dissertation shows that the variability in metric values applied in biological assessment is often high. We should face the issue of high variability by gaining a better understanding of ecosystem functioning and unraveling cause-effect mechanisms, as well as, by developing more cost-effective sampling and sample processing methods. A short-term solution to reduce variability and improve the performance of currently applied assessment systems in the Netherlands would be the implementation of quality assurance and quality control procedures. Additional standardization of the sampling and sample processing protocol is required, especially in terms of sorting effort. In the long run, water managers need to consider applying probability sampling to draw statistically sound conclusions at water body/national level. Combining probability sampling with a relatively cheap sampling and sample processing method to assess ecological status (‘Quick Scan’ method) will result in more cost-effective monitoring programs.
- Author's name on the title page: H.E. Vlek.
Research conducted at: Universiteit van Amsterdam
Series: Alterra scientific contributions 44
If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library, or send a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible.