Evaluating the ecological impact of an oil spill is a complex issue
requiring coherently articulated examination of the sequence of interactions
that link the cell, where contaminants exert their effects, to the
ecosystem, where interactions with human activities arise. This sequence of
interactions traverses the frontiers between scientific disciplines
(chemistry, toxicology, physiology, and fisheries ecology). Using the common
sole (Solea solea L.) as a model species for the coastal habitats polluted by the
“Erika” oil spill, our research project attempted to define indices of functional
integrity that characterised the consequences of fuel exposure at the
different biological levels. The coupling of field observations with
experimental laboratory work revealed how functional alterations which are
readily observable within individuals and their organs are progressively
obscured as investigation progresses towards more complex organisational
levels. Some of the approaches and indices are proposed as instruments for
evaluating the impact of contamination by hydrocarbons.