Laboratory study of ecotoxicological effects

The risk assessment of chemicals in the marine environment suffers from a number of limitations such as the very limited availability of ecotoxicity data for marine organisms and the difficulty to evaluate the potential effects of complex mixtures of low-level concentrations of micro-pollutants. In order to understand and explain the ecotoxicity of realistic environmental mixtures, we need to know in the first place more about the toxicity of the individual compounds in the mixture. Yet, for marine biota, chronic toxicity data are lacking for most  substances, and even more so for polar substances. This activity therefore aims to increase the knowledge on marine ecotoxicity and to combine field sampling with passive samplers with biotesting of environmentally realistic contaminant mixtures.

The contaminants and mixtures of interest will be tested using standard ecotoxicity assays: the Phaeodactylum tricornutum (algae) 72h growth inhibition test performed according to ISO standard 10253 (ISO 2006) and the Crassostrea gigas (oyster) 24h larval development test according to ASTM (1995). Other tests such as the harpacticoid copepod development and reproduction test with Nitocra spinipes or the fish embryo acute toxicity (FET) test according to OECD guideline 236 (OECD 236) are additional options that could be considered to further increase the confidence in risk estimates.

Further, in this activity, we aim to extensively validate the formerly developed ‘passive dosing’ technique (see “INRAM project”) by exposing test organisms to realistic mixtures obtained through release of contaminants from passive samplers deployed in the marine environment.

The results of research performed in this activity will:

  • further optimize and validate the application of passive samplers as dosing devices for laboratory bioaccumulation and effect assessments,
  • examine and establish possible relationships between realistic mixture compositions and adverse effects in several marine species,
  • offer practical tools for effect assessment of realistic mixtures by a range of assays, using passive dosing in ecotoxicity experiments with organisms of different trophic levels.