Ecological quality assessment of Dutch surface waters using a new bioassay with the cladoceran Chydorus sphaericus

Routine chemical monitoring gives insight in the presence of contaminants in surface waters, but not in their joint ecological effects. Therefore ecological water quality is assessed with bioassays. Recently, a new bioassay using the chydorid Chydorus sphaericus has been developed. Working with smaller volumes, materials and being less time consuming than the traditional Daphnia magna test regarding the culture and experimental design, the ‘Chydotox-test’ shows a comparable sensitivity. The new Chydotox-test is a promising alternative for the existing Daphnia sp. acute immobilisation test (OECD 1984).