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Summary
The presence of organic contaminants in top-predators in the Arctic
ecosystem has been known for decades (Bowes & Jonkel, 1975). These compounds are
transported to the Arctic environment through atmospheric deposition, by ocean currents
and or by river flows and ice drift (e.g. Barrie et al., 1992, Pfirman et al.,
1995). However, little information exists on levels of organic contaminants in the
different sources as well as on the transfer of these compounds between the abiotic
sources and the organisms in the food chain. The aim of the project proposed is to analyse
the content of organic contaminants in sea ice, sea water, snow and algae samples
collected in the marginal ice zone in the Barents Sea and north of Svalbard and to
calculate bioconcentration factors from the abiotic compartments to the lowest trophic
levels of the food chain.
Background
Organic contaminants are transported to the Arctic environment through
different pathways such as river run-off, water mass circulation and long range atmosperic
transport (e.g. Klungsøyr et al. 1995, Pfirman et al. 1995). Contaminants
such as polychlorinated biphenyls (PCBs), chlorinated pesticides and poly aromatic
hydrocarbons (PAHs) are of special concern in the Arctic due to their persistence and
physical-chemical properties (Barrie et al. 1992).
Sediments deposited on the shallow Arctic shelf seas become
incorporated into newly forming ice (e.g. Nürnberg et al. 1994). Organic
contaminants have high affinity for particles, especially fine grained material, and
become co-enclosed with the sediment material during the freezing process (Reimnitz et
al. 1990, 1993). Sea ice formed in the Kara Sea has been shown by model simulations to
enter the Barents Sea, between Frans Josef Land and Novaja Zemlya and from north, between
Frans Josef Land and Svalbard (Detleff et al. 1997). When encountering the warm
Atlantic water north of north and northwest of Svalbard, melting takes place. The same
mechanism takes place in the marginal ice zone (MIZ) in the Barents Sea (Pfirman et al.
1995), where the branch of warm Atlantic water traversing the Barents Sea before exiting
to the Arctic encounters the ice edge. During the melting period, the marginal ice zone
experiences an intense spring bloom, and the temporal coherence of a bloom and release of
material from the melting sea ice enhances the risk of uptake of contaminants by the
lowest trophic levels in the food chain. Once incorporated into these organisms, the
contaminants can be transfered and biomagnified up the food chain. A number of field
measurements show an increase in concentration of organic contaminants the higher up in
the trophic food chain (Broman et al., 1992, Jarman et al., 1997). High
concentrations of DDT and PCB have been found in top predators such as arctic fox, glaucous
gull and polar bear (Norheim et al. 1992, Wang-Andersen et al., 1993; Espeland et
al. 1994, Gabrielsen et al., 1995; Bernhoft et al., 1997).
Oceanic currents and atmospheric long transport of contaminants are
additional pathways for organic contaminants to reach the Arctic environment (Pfirman et
al. 1995), where latter potentially is the largest (Bidleman et al. 1992).
Special features of the Arctic environment such as low temperatures and low solar
radiation slow down degradation and dissipation processes of organic contaminants
(Chernyak et al. 1996, Rice & Chernyak 1997) and high concentrations of
pollutants are found in the arctic atmosphere, especially during winter months. These
elevated concentrations are most likely a combined result of lowered rates of particle and
gas removal and a stable atmospheric system (Shaw 1995). Deposition of these compounds
onto sea ice through precipitation contributes to the overall contaminant load of sea ice.
While a number of data exists on levels of organochlorines in the atmosphere (e.g. Wania
& Mackay 1996), no such corresponding measurements have been made of the dissolved
phase in sea water.
Independent of the origin of the organic contaminants in sea ice,
during the melting period, compounds adsorbed or enclosed in the sea ice will be releases
into the aquatic environment. Organisms with life cycles related to sea ice will during
this period be exposed to elevated levels of these compounds (Alexander 1995, Pfirman et
al. 1995). Factors such as age, origin and distribution of the sea ice will influence
the amount of material deposited, fraction of the material released during the melting
process and the amount of organic contaminants available for uptake by the organisms.
At present, only few data are available on the load of organic
contaminants in the abiotic compartments of the Barents Sea. The aim of the project
proposed is twofold, firstly to detect the levels of organic contaminants in sea ice, sea
water, snow and algae and secondly, calculate bioconcentration factors of the contaminants
from the abiotic environment to the lowest trophic levels of the food chain. Since the
project described covers the levels of contaminants available to organisms from the
ambient abiotic compartment, the results will be set in relation to the data obtained from
studies of bioconcentration and biomagnification in marine organisms connected to the
drift ice in the Barents Sea ("Perstistent organic pollutants in marine organisms in
the marginal ice zone of the Barents sea; bioconcentration and biomagnification" -
project proposal by the Norwegian Polar Institute).
Objective
The objective of this study is twofold, i.e. to detect levels of
organic contaminants in the abiotic marine environment and to calculate bioconcentration
factors from these sources to the lowest trophic levels of the marine food chain in the
areas investigated. Measurements of both the particulate and dissolved phase will be made,
which includes pioneer work regarding analysis of organic contaminants in the dissolved
phase. The program is sub-divided into two phases, where the second phase will contribute
with coverage of seasonal and geographical variability in levels and transfer of organic
pollutants, a feature known from other areas (e.g. Axelman et al. 1997).
Phase I
- Analyse and compare levels of organic contaminants in sea ice, sea water, snow and algae
samples collected in the marginal ice zone in the Barents Sea and north of Svalbard in
1997-1998.
- Calculate bioconcentration factors of organic contaminants from the abiotic compartments
to the lowest trophic levels in the marine food chain.
The contaminants included in this part of the project are non-planar
PCBs, PAHs, and pesticides such as DDTs, HCHs, HCB, toxaphene and chlordanes.
Phase II
The data compiled from phase I will be harmonised with results from
the bioconcentration and biomagnification study of the Norwegian Polar Institute in order
to work out a detailed expanded sampling program in 1999-2000 on the transfer of
contaminants between the two compartments. Additional field sampling is required to obtain
a better seasonal and geographical coverage of the contamination levels as well as to
detect variability in uptake of organic contaminants between species and season.
All the data collected will be compiled in a uniform database,
harmonised with the results obtained from the project "Perstistent organic pollutants
in marine organisms in the marginal ice zone of the Barents sea; bioconcentration and
biomagnification" (Norwegian Polar Institute), and incorporated into scientific
publications.
The purposes of the project is to:
- Detect levels of organic contaminants in sea ice, sea water, snow and the lowest levels
of the food chain.
- Calculate bioconcentration factors from the abiotic compartments to the lowest levels of
the food chain.
- Detect seasonal and geographical variability
Methods
Sampling
The samples collected in 1997 include three cores of multi year ice
samples collected north of Svalbard onboard Jan Mayen (3-16 Sept. 1997). Sea water from
the marginal ice zone in the Barents Sea was collected and filtrated onboard R/V Jan Mayen
(17-30 May 1998). During the same expedition, algae samples were collected from two
stations. A ship of opportunity based sampling program where sea water samples are to be
collected will take place between the 9-22 September 1998 onboard R/V Jan Mayen. The
expedition will traverse waters north-west and north of Svalbard, with three 24 hour
stations in the ice north of Svalbard. Sea water samples will be collected together with
ice algae.
The field sampling program in 1999 will take place during a) spring
(Norwegian Polarinstitute, F/F Lance) and b) autumn (expedition organised by
Norwegian Polar Institute).
Sea water samples will be collected with a stainless steel filtration
system. The water will be pumped onboard through pre-combusted glass-fibre filters
(Whatman GF/F) with a cut off of 0.7 m m to retain particles
and thereto-associated OCRs. The dissolved Ocs are trapped from the filtrate on a
polyurethan foam (PUF) column. Sea ice, snow and organism samples will be collected in the
field, stored at -20 ° C and filtrated according to the
procedure used for sea water at the time of analysis. Taken all together some 25-40
samples are expected to be collected during this period. If required to supplement data,
participation in the year 2000 spring expedition organised by the Norwegian Polar
Institute (ICE-BAR II) can be taken into consideration. The samples collected will be
stored at –20 ° C at Akvaplan-niva prior to analysis in
1999.
Analysis
All samples will be analysed for content of non-planar PCBs, PAHs
and a range of pesticides including DDT, HCHs, HCB, chlordanes and toxaphen by the
laboratory at Stockholm University. The amount of parameters analysed will be in relation
to the financial coverage. All samples are stored at –20 °
C at Akvaplan-niva prior to analysis.
Budget
Participation on expeditions in 1997 and 1998 onboard R/V Jan Mayen
have been made possible by the Norwegian College of Fishery Science (NFH) and the
University of Svalbard (UNIS), why no additional field costs need to be included in phase
I of the project proposal. The sampling equipment has kindly been supplied by the
University of Stockholm without any financial costs apart from those related to shipment
of the equipment and the analytical material used within the project. Stockholm University
will also contribute with costs involved in data processing and reporting (80 000 NOK).
Akvaplan-niva will contribute with 1/3 of the cost from scientific publications and an
additional 100 000 NOK to cover the field programme.
Total budget for 1998 and 1999: NOK 630 000,-.
The financial support from the individual participating institutes to
the project amounts to 230 000 NOK (Stockholm University 80 000 NOK, Akvaplan-niva as 150
000 NOK), rendering the total sum applied for within the project to 400 000.
Schedule
Autumn 1998: Field sampling and filtration of sea water and ice algae
(9-22 Sept.).
Spring 1999: Analysis of material collected during 1998.
Field sampling and filtration program
Autumn 1999: Field sampling and filtration program
Analysis of material collected during 1999.
1999-2000: Scientific article preparation
Cooperation and associated participants/applicants
Dr. Johan Axelman, Aquatic Chemical Ecotoxicology, Stockholm
University
PhD student Katrine Borgå, Norwegian Polar Institute, Tromsø
Prof.. Dag Broman, Inst. of Applied Environmental Research, Stockholm
University
Salve Dahle, Akvaplan-niva as, Tromsø
Dr. Geir Wing Gabrielsen, Norwegian Polar Institute
Dr. Kristina Olsson, Akvaplan-niva as, Tromsø (project leader)
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