Research Articles Chlorinated Dibenzo-p-Dioxins and Dibenzofurans in the Baltic Herring and Sprat of Estonian Coastal Waters

very much from year to year, it would be better to carry out surveys only every 3–4 years and, instead, stratify the sam-pling according to age and gender of the fish, and to analyze replicate extracts by replicate measurements. The inclusion of unmarked replicate samples would be a good quality assur-ance measure. It would be desirable to analyze additional parts of the food chain in order to understand the fate of the com-pounds in the ecosystem