FOODCHAIN ACCUMULATION OF PCDD AND PCDF ISOMERS IN THE GREAT-LAKES AQUATIC COMMUNITY

As part of an on-going Great Lakes contaminants monitoring program, samples of fish and invertebrates were analyzed for concentrations of 2,3,7,8-T4CDD plus all other 2,3,7,8 substituted dioxin and furan isomers. Analytical data for fish samples from each of the Great Lakes provided spatial trend information. Typical components of a Great Lakes aquatic ecosystem foodchain, including plankton, invertebrates; Mysis relicta and Pontoporeia hoyi, forage fish species, alewife, smelt and sculpin plus lake trout, a representative top predator species, were analyzed to provide a measure of biomagnification in the system. Annual archived lake trout whole fish homogenates, dating from 1977, were analyzed for dioxin and furan isomers to provide temporal trend data. Additional measurements of biological effects including the incidence of skeletal anomalies and blood cell composition, were carried out to relate contaminant burden with indices of ecosystem health.