3D - Exposure and effects of environmental contaminants in marine organisms
Poster Hall
8:30 AM - Tuesday, 29 April 2003
Chair: Scholz, N.1, 1
Co-chair: Karbe, L.2, 2

(TUP/183) The use of time variable dose-effect relationships in oil spill effect modelling.

Smit, Mathijs1, Koops, Wierd1, 1 TNO-MEP, Den Helder, Netherlands

ABSTRACT- In any situation an oil spill has large negative effects on the aquatic environment. In order to facilitate decision-making on oil spill response options based on both ecological and economical parameters, the Net Environmental and Economical Benefit Analysis model (NEEBA) has been developed. This model consists of an oil behaviour module, a response module and an ecological effect module. In the oil behaviour module a quantitative division of the oil volume over air, water surface and water column is determined on the basis of spreading, transport and weathering. With the ecological effect module the effects are calculated based on the exposure concentrations in the water column and at the water bottom as well as the layer thickness on the water surface. The exposure concentrations are calculated over time. With these data, effects can be calculated on several trophic levels: birds, fish, shrimp/molluscs and zooplankton The effect module calculates the effects based on time dependent dose-effect relationships. These relationships are defined based on a large set of EC50s and slope values for different species at different exposure times from toxicity tests with dispersed oil. With the obtained dose-effect curves and their relation to exposure time it is possible to estimate any effect at a certain concentrations and at a certain exposure time. These relationships are used to estimate the effects from exposure to the concentrations as determined in the behaviour and response modules. The NEEBA model is a valuable tool to support decision-making and gives insight in the environmental effects related to a particular response option

Key words: NEEBA, effect modelling, oil spill response