Contaminants
Samples of suspended particulate material
were collected in the top 30 m of the water col-
umn at many stations using a system capable of
pumping and filtering large volumes of water
quickly. These samples will help us to determine
the fractionation of contaminants between dis-
solved and particulate phases, an important aspect
of the process of scavenging and removal of con-
taminants from the euphotic zone.
Samples of zooplankton were collected using
vertical net hauls in the top 100 m of the water
column. These will be analyzed for organochlor-
ine contaminants, which will determine the level
of biomagnification in the lower part of the food
chain. Cod, a species higher in the food chain,
were collected opportunistically across the tran-
sect. By combining the zooplankton and cod data,
we have a unique view of both bioaccumulation
and biomagnification of organochlorines in the
food chain across this section.
Sediment cores were collected at eight stations
spanning the cruise track. Samples from these
cores will be analyzed to provide information on particle-active contaminants,
Fiona McLaughlin
drawing water sam-
for example, lead, highly chlorinated organochlorines and PAH (polynuclear
ples from the Niskin
aromatic hydrocarbon). The levels of these contaminants will be examined to
bottles for chemistry
analysis on the
determine both the spatial trends across the transect and the importance of
Louis S. St-Laurent
sediments as sinks for contaminants within the Arctic Ocean.
Although many samples are already under analysis, we do not yet have any
contaminant data for AOS-94. The process of analysis is complex and lengthy,
involving several analytical tools, for example, high-resolution mass spectrometry
and electron-capture gas chromatography. Information from the Larsen-93 cruise,
which collected samples from a region that overlaps the early portion of the AOS-
94 transect, suggests that we will find regional differences in contaminants
produced both by delivery mechanism (transport within water masses) and by
removal mechanism (biological productivity and the supply of particles). Un-
derstanding the relative importance of these mechanisms is crucial to our abil-
ity to predict the effects these compounds are likely to have on the Arctic
community and the time required for a response to any environmental change,
including a removal of the source.
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