Distribution of Chlorinated Hydrocarbon Pesticides and PCBs in the ...

Arctic Ocean are extremely low (Gordon and Cranford, 1985).
Since there is insufficient light for photosynthesis for many
months of the year, the supply of organic matter is very
seasonal. The necessity for organisms in this environment to be
able to store energy-rich substances may make them more
susceptible to contaminants than organisms in more temperate
regions. This in turn may lead to a more- efficient transfer of
contaminants to the higher trophic levels including arctic
consumer organisms.
Relatively high levels of PCBs and chlorinated hydrocarbon
pesticide residues have been found in arctic marine mammal and
fish tissues in several recent studies (Nordstrom et al., 1985;
Thomas and Hamilton, 1988). This has direct relevance to
Canadian arctic regions where native people still rely on marine
mammals and fish for a large portion of their protein and caloric
intake. Observations of PCBs and chlorinated hydrocarbon
pesticide residues in blood samples from many Inuit from the
community of Broughton Island on Baffin Island (Kinloch and
Kuhnlein, 1987) that exceed tolerable concentration limits set
by Health and Welfare Canada emphasize this point.
The present study used the opportunity provided by the
Canadian Ice Island Station to expand the available data base for
these compounds in the high Arctic with the objective of
examining the distribution of chlorinated hydrocarbon pesticides
and PCBs in various compartments of the Arctic marine environment
and food web.
1.1 objectives
The terms of reference for the work carried out were to:
1) determine ambient concentrations of selected chlorinated
hydrocarbon pesticides and PCBs in the water and bottom
sediment off Canada's northern outer coast;