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Environmental Contaminants and Pathways
Strait of Georgia
Contaminant Transport
- Project Leader: Robie
W. Macdonald
Accounting for particle transport to and within and out of the Strait of
Georgia is fundamental to an understanding of the transport of
non-conservative contaminants. Virtually all priority contaminants
partition onto solids, and through this pathway they enter into the
biosphere usually through consumption either in the water column or in
the sediments. In this project, it is our intention to use sediment core
data together with sediment trap data to produce syntheses of sediment
transport for the Strait of Georgia.
The expected results of this project are:
-
provide topical syntheses of
contaminants (eg footprint of Iona outfall using Ag as tracer);
- investigate one or more cores for PBDE
content to seek for trends, sources and amounts;
- construct a synthesis of the sources of
PAH to the Greater Strait of Georgia using dated cores from Fraser Basin
lakes and from the Strait of Georgia;
-
commence construction of models that
incorporate non conservative properties for Strait of Georgia
-
commence construction of a budget for
sediments and organic carbon for the Strait of Georgia
Results from previous years of the Strait of Georgia Project have
contributed in whole or partly to the various articles listed on Robie
W. Macdonald's publications page.
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Biotransport
of POP's by Anadromous Fish -
Project Leader:
Robie
W. Macdonald
Sediment cores have been collected from British Columbia and Alaskan
Lakes. These have been sectioned finely, dated and analyzed for fish
biomarkers plus organochlorine compounds. Lakes encompassing the entire
N-S range of BC together with selected Alaska Lakes will be included in
the study. Funding will allow for the hiring of a graduate student via
Ottawa University (co supervised by J. Blais and R. Macdonald).
The lake cores are expected to contain records of fish returns in their
chemical and isotopic signature. The sediments will be evaluated for
correlations and patterns that identify if the fish are sources of
organochlorine chemicals to the lakes and, if so, how important this
source of contamination is relative to direct atmospheric inputs. We
expect to be able to determine the sources of OC contaminants to remote
BC lakes within the major river systems.
Duplicate sediment cores have been collected from North and East Barrier
Lakes and Fraser Lakes, as good candidate locations based on fish
escapement records. These cores have been dated and analyzed for a suite
of organochlorine contaminants. In addition, a small set of samples have
been obtained from several Alaskan Lakes which have extremely high
escapements to provide a range in the bio-transport strength. Results
show trends related to fish density based on the d 15N proxy.
In 2002, additional lakes in the Fraser Drainage have been selected and
sediment cores collected (Shuswap, Moose, Bowron and Quesnel Lakes).
Samples are presently undergoing analyses. Initial results from Alaskan
Lakes show that biotransport by anadromous fish is more important than
atmospheric transport for a number of lakes (Krummel et al. 2003).
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Alpha-/beta-HCH measurements
- Project Leader: Robie
W. Macdonald
Alpha and beta HCH records for the North Pacific and Arctic reveal some
important differences in transport pathways. Beta HCH, which is probably
the compound that puts humans and ecosystems most at risk, has been
largely ignored. In recent papers, Li et al (2001, 2004) have pointed
out the importance of understanding how beta hch gets to the Arctic both
from the point of view of assessments but also for the production of
meaningful environmental contaminant models. We have collected data on a
transect to the Arctic in 2002. These data will contribute to the only
water-column time series available for these compounds.
We are continuing to analyse and interpret sectional samples for the HCH
family including Bering Sea, Bering Strait and the Beaufort Sea.
The CACAR and AMAP assessments will be completed in 2002-2003.
Contributions to the ongoing AMAP and CACAR assessments are being
conducted based on data collected during the past 5 years under the NCP
program, and interpretations of the SHEBA data (including both climate
and contaminant aspects) are being worked into published literature.
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University of Maryland -
Project Leader:
Robie
W. Macdonald
Under the Shelf-Basin Interaction project funded by NSF (USA) ARCCS
project, we are collaboratively examining sediment records from the
Chukchi and Beaufort Seas and the Arctic Basins to determine the sources
of organic carbon and processes leading to their preservation or
destruction. These data and interpretations provide important components
of understanding for the organic carbon cycle in the Arctic, its
vulnerability to change and the impacts on the climate. It is expected
that the data collected/analyzed within this project will be augmented
and matched by similar work to be conducted under the CASES program once
it starts to conduct field work.
We will produce a detailed organic geochemical data set for sediment
cores collected from the Chukchi, the Beaufort and the Canada Basin.
Additional samples of phytoplankton, zooplankton and suspended
particulate will be analysed for a suite of biomarkers including alkanes,
fatty acids, sterols and other biomarker compounds. These will be
interpreted in the context of sources, sinks and processes by publishing
focused papers in international journals.
We have produced a synthesis paper by retrospective analyses of the
sediments collected during the Arctic Ocean transect (Belicka et al.,
2002) and have made presentations at several SBI workshops plus the most
recent Gordon Research Conference on organic geochemistry. A second
paper has been published on the findings of our Chukchi sediment cores (Belicka
et al., 2004). A book has been produced (Stein and Macdonald, 2003) on
the organic carbon cycle in the Arctic Ocean with some of the data from
this project being included in various chapters.
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