Optimal modeling and monitoring in ecotoxicological assessments: Choosing instruments for applied research and management with examples from the Rhine‐Meuse delta

Abstract

Ecotoxicological management and research have several instruments at their disposal. A discriminatory is made between monitoring of chemical, biochemical, toxicological and ecological parameters, and modeling at a simple, intermediate, and complex level. Their usefulness is discussed and illustrated by examples from the Rhine-Meuse delta.Each type of instrument has its own benefits. In simple cases, application of one instrument will do. More often, however, the objectives set, the compounds concerned, and the species involved require a combination of tools to be used. Chemical and biochemical parameters are oriented around sources and concentrations of well-known priority substances. Toxicological and ecological variables, on the other hand, are directed toward species and the impact of these compounds and other factors as well. In the Rhine-Meuse delta, contamination decreases and more refined instruments are needed to pick out the compounds and species that should get our attention most. An intermediate level of modeling is considered the next logical step after application of simple rules of thumb.

Variation in the availability of metals in surface water, an evaluation based on the dissolved, the freely dissolved and Biotic Ligand Model bioavailable concentration

“…A broader adaptation of water quality influencing the bioavailable metal fraction and hence the water quality standard has been hampered by the perceived complexity of FIAM modeling. While simpler multiple regression models have been developed (van Hattum et al, 1996;Hendriks and van de Guchte, 1997), these models were not adapted by policy makers. In the last ten years BLM models are slowly being adapted within the EU for second tier risk assessment of monitoring data (Rüdel et al, 2015).…”

“…The numerical model 'Optimal Modeling for Ecotoxicological Assessment' (OMEGA) incorporates these methodologies to calculate the ecotoxicological risk for multiple contaminants (Hendriks and Van de Guchte, 1997). The model used the ecotoxicological data for approximately 200 substances (Bruijn de et al, 1998).…”