Aquatic risk assessment for carbaryl - recovery of cladocerans
Poster at the EUFRAM Project Meeting 2, Zeist, The Netherlands, 18. - 21.10.2004
In EUFRAM case study 1, aquatic risk assessment for carbaryl, the risk assessment was differentiated according to ecophysiology and habitat of the species. Planktonic filter feeders like Daphnia or other cladocerans were identified as the most critical taxa, because of their high sensitivity and exposure in lentic waters. Based on a few micro- and mesocosm studies, the high recovery potential of cladocerans was taken into account and the NOEAEC was suggested to be 10 µg/L. The objective of the simulation studies shown here was to support this information by combining basic information about species ecology and uncertainties about species sensitivity and exposure. Our results correspond well with the results of model ecosystem studies indicating recovery of Daphnia within a few days at 15 µg/L (Hanazato & Hirokawa 2004) and within 6 weeks at initial concentrations of 100 µg/L (Hanazato & Yasuno 1990). Therefore, even for the exposure scenario with the lowest mitigation measure, a recovery of cladocerans within a few weeks is likely due to the fast dissipation of carbaryl and the high recovery potential of the cladocerans.