Scoring fish assemblages: advantages, disadvantages and needs for intercalibration

Jan Breine

INBO, Institute for Nature and Forest, Belgique

The use and the advantages of fish as a biotic quality element for the assessment of the ecological status of rivers is well documented (e.g. Karr, 1981, Hughes & Oberdorff, 1999, Schmutz et al., 2007). The characteristics of fish assemblages are quantified by metrics that compose an index of biotic integrity (IBI) (Karr, 1981). Verneaux (1981) pioneered the first multimetric index to assess the water quality in French rivers using fish communities and benthic macroinvertebrates. Estuaries are highly dynamic and complex ecosystems and the development of fish-based indices delayed. Thompson & Fitzhugh (1986) were among the first to integrate fish metrics in an index to assess the ecological quality of an estuary. In this presentation advantages and disadvantages of fish-based indices are discussed.

The European Water Framework Directive (WFD, 2000) provides the framework for the protection of ground- and surface waters whereby the different member states involved have to follow a tight time schedule to reach good ecological status for all water bodies. In 2002 the Water Directors endorsed a document called ‘Towards a guidance on establishment of the Intercalibration network and on the process of the Intercalibration exercise’ (Intercalibration Guidance). This intercalibration process is aimed at consistency and comparability of the classification results of the monitoring systems operated by each Member State for the different biological quality elements. The needs for the intercalibration exercise are given and some solutions are suggested.

EU Water Framework Directive, 2000. Directive of the European parliament and of the council 2000/60/EC establishing a framework for community action in the field of water policy. Official Journal of the European Communities 22.12.2000 L 327/1.
Karr, J.R., 1981. Assessment of biotic integrity using fish communities. Fisheries, 6: 21–27.
Hughes, R.M. & T. Oberdorff, 1999. Applications of IBI concepts and metrics to water outside the United States and Canada. In Simon, T.P. (ed.), Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press LLC, Washington DC: 62-74.
Schmutz, S., Melcher, A., Frangez, C., Haidvogl, G., Beier, U., Böhmer, J., Breine, J., Simoens, I., Caiola, N., de Sostoa, A., Ferreira, M.T., Oliveira, J., Grenouillet, G., Goffaux, D., de Leeuw, J.J., Noble, R.A.A., Roset, N. & T. Verbickas, 2007. Spatially based methods to assess the ecological status of riverine fish assemblages in European ecoregions. Fisheries Management and Ecology 14, 441–452.
Thompson, B.A. & G.R., Fitzhugh, 1986. A use attainability study: an  evaluation of fish and macroinvertebrate assemblages of the lower Calcasieu River, Louisiana. Center for Wetland Resources, Coastal Fisheries Institute, Louisiana State University, Baton Rouge. LSU-CFI-29. 143 pp.
Verneaux, J., 1981. Les poisons et la qualité des cours d’eau. Annales Scientifiques de l’Université de Franche-Comté Besançon, Biologie animale, 4 (2): 33-41.