Determining sediment quality for regulatory proposes using fish chronic bioassays

Sediment quality assessments for regulatory purposes (i.e. dredged material disposal) are characterized by linking chemical and acute ecotoxicological data. The design of chronic bioassays that incorporate more sensible endpoints than acute tests is discussed to address sediment quality for environmental quality assessment and regulatory proposes. The chronic tests use juveniles of commercial species of fish Sparus aurata and Solea senegalensis, to assess sediment toxicity in samples collected along different littoral areas in the North and the South of Spain. The organisms were exposed during 60 days and sublethal endpoints were selected including biomarkers of exposure to metals (metallothioneins - MTs) and to organic contaminants (ethoxyresorufin-O-deethylase activity - EROD activity) and biomarkers of effect (histopathology in different tissues, gill and liver). A Multivariate Analysis Approach was conducted in order to associate these biological responses with sediment metal concentration from the ports and with chemical residues in biological tissues exposed to sediments under laboratory conditions.