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Environmental pollutants in marine food chains in northern seas Proposal for a programme to improve our basic
knowledge concerning Translation of parts of the Norwegian programme
proposal "Miljøgifter i marine næringskjeder i nordlige
havområder" The proposal has been prepared for the Ministry of the
Environment by a working group representing: Comment: This programme proposal has been approved by the Ministry of the Environment and the Ministry of Foreign Affairs as the scientific basis for the ongoing research. However, the funding has so far not been adequate to cover all tasks described here.
1. Introduction
A letter dated 16.10.95 from the Ministry of the Environment to the Norwegian Polar Institute (NP) asked the latter to take responsibility for establishing and heading a working group to assess the need for more knowledge about the transport and effects of environmental pollutants in Arctic marine food chains. The group should consist of representatives from NP, the Directorate for Nature Management (DN), the State Pollution Control Authority (SFT), the Directorate of Fisheries, Institute of Marine Research (HI) and the Norwegian Radiation Protection Authority (NRPA), and these have been:
In addition, Brit Salbu (Agricultural University of Norway, NLH) has participated in several meetings and made valuable contributions. Other staff in the aforementioned institutions have also helped to draw up the programme. The objective of the programme is to help the authorities to obtain a satisfactory pool of basic knowledge to be able to design and implement a monitoring programme for the northern seas and assess the state of the environment, including evaluating the consequences for both health and the environment of the continual input of pollutants and of acute emissions. The knowledge acquired is primarily intended to cover the needs of environmental management, but will also fill important gaps in knowledge held by the fisheries and health authorities. The programme is directly aimed at management problems and is not a pure research programme. Evaluations of the present situation and environmental impact assessments form an essential basis for deciding measures to counteract damage to the environment. Relevant measures for the northern regions may prove both extremely costly and controversial, and will necessarily require international co-operation, since other countries are mainly responsible for the input of contaminants. The demands for documentation will thus be substantial and will probably increase in the years ahead. In this context, the task of achieving a better understanding of how contaminants affect organisms and populations will be extremely important. The programme will focus upon the assimilation and transport of environmental pollutants in marine food chains and the exposure to, accumulation in and possible effects on organisms and populations of these pollutants. To acquire quality assurance of the scientific content of the
programme, the working group found it desirable to receive comments on the proposal from
relevant scientific bodies additional to those which it represented. A draft version was
therefore sent in June 1996 to the Norwegian Institute for Water Research (NIVA), the
Norwegian Institute for Air Research (NILU), the Foundation for Nature and Cultural
Heritage Research (NINA(NIKU), Akvaplan-niva, the Universities of Trondheim, Tromsø, Oslo
and Bergen, the Norwegian Institute for Veterinary Medicine, the Institute for Energy
Technology (IFE), the Norwegian Defence Research Establishment (FFI) and the secretariat
for the Arctic Monitoring and Assessment Programme (AMAP). Ten responses were received.
Scientific corrections and comments have been incorporated into the report. Gunnar Futsæter Norwegian Polar Institute In December 1995, the Ministry of the Environment (MD) appointed a working group to evaluate the need for knowledge linked with the assimilation, transport and effect of environmental pollutants in food chains in northern seas. The groups of substances to be evaluated were organic pollutants, radionuclides and heavy metals. The working group would also draw up a proposal for a Research and Development programme to cover the most significant gaps in our knowledge in this field. The objective of the programme is to help the authorities to obtain a satisfactory pool of basic knowledge to:
The group has formulated the following primary objective for the programme: To acquire information needed by the Norwegian authorities concerning the movement of environmental pollutants in Arctic marine food chains and their effects on marine ecosystems in the Arctic, including possible consequences for human beings. The knowledge acquired through the programme is primarily
envisaged to cover the needs of environmental management, but should also be able to fill
important gaps in By reviewing the state of knowledge regarding contaminants in the Arctic marine environment the group has been able to identify significant deficiencies, which it hopes to redress through projects in the following fields:
The working group has drawn up a set of criteria to assist in ranking the priority of projects. The projects which are implemented must be co-ordinated with other relevant projects, and must also be viewed in the context of other environmental monitoring currently taking place in these waters. The group suggests that this Research and Development programme should be administered in the same way as "Nature's tolerance limits", an R & D programme run by the Ministry of the Environment. This means that a steering committee led by the Ministry will have overall responsibility for laying down the external constraints for the programme and overseeing the efforts of the working group. The latter will be responsible for the everyday running of the programme and for its scientific content, and will ensure that it remains within the constraints laid down. The programme focuses upon the Barents Sea and adjacent waters. This region has a large biological production and is specially important for commercial fish like capelin, cod and herring. The Barents Sea alone represents an important fishing area where annual catches vary from 2 to 3.5 million tonnes. Some of the world's largest populations of seabirds and marine mammals are found in these waters. Until a few years ago, the Barents Sea and the northern regions were looked upon as distant, unaffected areas, far removed from industrial and other anthropogenic sources of contamination. Recently, a number of investigations have been carried out which show that these areas receive an influx of pollutants - radionuclides, heavy metals and organic compounds - transported from industrial and agricultural regions outside the Arctic (Muir et al. 1992; Dahlgaard 1993). In addition, local sources exist (industry on the Kola Peninsula, dumping and storage of radioactive materials, petroleum activities on land and at sea, etc.), which also contribute to the contamination. The regional picture of the threats will probably change significantly in a relatively short time. Northern Russia is rich in natural resources such as minerals, timber, oil and gas. Its development potential is enormous and huge investments are expected to be made in the region during the coming decade. Even if a turbulent political situation and lack of clarification of external constraints for foreign investors put a brake on the development, plans are already at hand for developing, for example, petroleum fields both at sea and on land. Most of the oil is planned to be transported out of the region by ship to recipients in Europe. The same will be the case for any development in the Norwegian sector of the Barents Sea. Oil shipment will result in a substantial increase in shipping along the Norwegian coast and entail a significant risk for oil spills. Increased petroleum activity and shipping will also lead to more emissions of a variety of contaminants in the region. Depending upon the chemical states of the contaminants, this form of input can lead to biological assimilation and transport in food chains, accumulation in organisms, and sub-lethal to lethal impacts on organisms. Predators uppermost in the Arctic marine food chains, such as mammals and seabirds, are specially vulnerable to pollutants. As food items, marine organisms are, moreover, an important instrument for transferring the pollutants to man. Inputs of organic contaminants and heavy metals into the Arctic environment principally occur from industrial undertakings, agriculture and centres of population. Natural sources also contribute to the load of radionuclides and heavy metals in the environment of northern seas. The most important anthropogenic sources of radionuclides in northern seas are fallout from atmospheric testing of nuclear missiles, emissions from recovery plants, fallout from the Chernobyl disaster and dumping. Although we know little about the various kinds of radionuclides, a great deal is known about the different forms of heavy metals and organic compounds. A large proportion of the contaminants that are liberated end up in the marine environment through direct emission and transport via the atmosphere and via fluvial runoff. The annual formation and melting of ice are typical phenomena in the Barents Sea. Some 500 km3 of ice are transported annually from the Kara Sea into the Barents Sea north of Novaya Zemlya, but the transpolar ice drift to the Greenland Sea is substantially greater (4000-5000 km3) (Vinje & Kvambekk, 1991). Ice is transported from the coast of Russia to the Barents Sea, where it melts in spring and summer. Atmospheric pollution deposited in the Kara Sea region, or contaminants from the huge Russian rivers, will be capable of binding to sediment particles to be transported entrained in the ice until this reaches the meltout area of the Barents Sea. Too little is known about the significance of this transport relative to, for example, atmospheric transport, and about what happens to these contaminants in the meltout areas, as regards assimilation, transport and sedimentation. To ensure that human activities do not inflict serious long-term damage on these northern seas, the state and development of the environment must be monitored and environmental impact analyses of various activities and potential threats to the environment must be undertaken. A major goal of the monitoring will be to ensure that reliable knowledge is acquired regarding what is taking place with the environment, as regards both its state and the impacts on it. The monitoring needs to be planned as a long-term, permanent activity, even though it will be natural to periodically raise the effort in certain particularly relevant fields. It is important to establish a number of permanent base stations for monitoring in order to acquire time series of measurements that can tell us something about trends over time (trend monitoring). Traditionally, the environment has been monitored by recording levels of contaminants. In the future monitoring effort, there is a great need to be able to link information about levels to critical pollution loads and biological effects. To be capable of performing reliable and efficient environmental monitoring and impact assessments on the marine ecosystem it is essential to have extensive knowledge from several disciplines. Examples include data on the quantities of emissions reaching the sea via rivers, the atmosphere and other sources, information about the chemical states of the emissions in the various transport media, and geophysical information linked with meteorology and transport of water and ice. The concentrations in the environment and processes which control the exchange of contaminants between air, water, sediment and biota under Arctic conditions, are not well known. Many contaminants have a general low solubility in water and a high binding potential to particles. Particle dynamism and sedimentation processes are therefore of great importance for the transport and bio-availability of the substances. Little information exists about the importance of these processes for dispersion in Arctic seas. To be capable of undertaking efficient assessments of impacts and of the state of the environment, it is necessary to identify the most vulnerable parts of the ecosystem. It will therefore be important to obtain more knowledge about the biological assimilation and effects of contaminants under Arctic conditions. Some of the organic contaminants are characterised by their high persistence, tendency for bio-accumulation and ability to have serious biological effects. The effects that have been reported in animals include reduced ability for reproduction, influence on immune systems, neurotoxic effects and carcinogenic effects. The biological impact on organisms of different heavy metals will vary. Whereas lead and mercury affect the nervous system, the development of various forms of cancer in human beings is attributed to cadmium. The effect of radionuclides will be first and foremost dependent upon the radiation dose. A low dose may cause cancer or genetic damage, whereas a high dose will, in addition, be capable of damaging chromosomes, affecting the immune system, damaging embryos and producing sterility. Knowledge about assimilation into marine food chains is vital for a total evaluation of the biological effects. When assessing the potential for damage it is important to determine the amount (the dose) of contaminants that is transferred between trophic levels and also the connection between the chemical states and biological assimilation. The general processes that help to control the assimilation of organic contaminants and radionuclides are reasonably well known through work carried out in other areas. However, few such studies have been performed under Arctic conditions. Information about biological effects is also extremely limited since few such studies have been done in northern regions. In this context, it is important for studies to be undertaken of biological effects of contaminants at the level of individuals, which can have consequences for populations and/or ecosystems. The lack of knowledge referred to above has been pointed out in both national and international contexts. The Norwegian White Papers, "On Norwegian polar research" (St. meld. no. 42, 1992-93) and "On environmental conservation in Svalbard" (St. meld. no. 22, 1994-95) stressed it and pointed out that it is a problem in a management context. In connection with efforts on the part of Norway to establish comprehensive, long-term environmental monitoring of the northern seas it was pointed out an early stage that work should be initiated to fill several of the major gaps in our knowledge. A report to the Ministry of the Environment prepared in 1995 by the State Pollution Control Authority, the Norwegian Polar Institute and the Norwegian Radiation Protection Authority proposed that the implementation of such work should form an initial phase in a long-term monitoring programme. The report pointed out that more knowledge was essential in order to both design more efficient and better targeted monitoring programmes and be able to analyse and evaluate environmental data that are gathered in. From the outset (AMAP Report 93:3), the "Arctic Monitoring and Assessment Programme" (AMAP) has emphasised the importance of data concerning effects on biota and the need for monitoring these effects. However, the participating countries have put little emphasis on collecting data on effects, and huge gaps in our knowledge still exist, as is pointed out, among elsewhere, in the AMAP report to the Ministerial Meeting in 1996 (AMAP Report 96:1). It is stated there that the lack of knowledge about assimilation, biotransformation, expression and effects hinder the assessment of consequences. In the context of environmental co-operation between Norway and Russia, more information on the effects of contaminants will be important in connection with joint environmental monitoring of these maritime areas and the implementation of joint environmental impact assessments and risk analyses. The need for more knowledge in this field is pointed out in the environmental status report for the Barents Sea and the White Sea prepared under the auspices of the Joint Norwegian-Russian Environmental Commission (Lønne et al. 1997, in prep.). An improvement in our basic knowledge on assimilation, levels of critical loads and effects of environmental pollutants will be important for being able to support or accelerate international measures to control pollution emissions. An important part of the platform for such decision making will be the ability to estimate the effects of pollutants on the individual and population levels based on observed pollution (levels) in the physical environment, or in organisms, and/or on the basis of known emissions to the environment (i.e. linking the influence to the effect). Against the background of the aforementioned needs for knowledge, and as part of the task of environmental management to prepare a comprehensive and long-term monitoring plan for environmental pollutants in the northern seas, the Ministry of the Environment appointed a working group in October 1995 that was given the following terms of reference: The working group will assess the need for more knowledge regarding transport of environmental pollutants in marine food chains and their biological effects on the marine ecosystem in the Arctic. It may also engage other Norwegian scientific groups in this work. A proposal must be prepared for a programme to fill the most significant gaps in existing knowledge. This programme should contain a proposed schedule and a cost estimate. Demarcation lines must be drawn up to ongoing and planned research in this field to avoid doing work twice and to ensure that the projects are relevant for covering management requirements. This particularly applies to work being done under the auspices of the Research Council of Norway regarding the research programme on ecotoxicology and the national radiation protection programme, as well as corresponding research collaboration with the European Commission (EU). The Ministry of the Environment has stressed that the programme must help to cover the needs of environmental management for knowledge to put it in a position to establish and carry out environmental monitoring, and must provide a basis for assessing the consequences of emissions of contaminants. The results of this programme, along with those from the programme entitled "Transport and fate of contaminants in northern seas", which was also prepared under the auspices of the Ministry), along with information which AMAP will provide in 1997, should be able to form a scientifically satisfactory basis for implementing future environmental monitoring of contaminants in northern seas. It is envisaged to carry out the "effect programme" over a 3-4 year period. The Ministry of the Environment also asked the working group
to make priorities between the various information requirements that are identified. 1.3 Objective, demarcations and amplifications On the basis of the terms of reference, the working group has formulated a principal objective. For both practical and budgetary reasons, there has also been a need to amplify and demarcate the work of the group.
The principal objective of the programme is: To acquire information needed by the Norwegian authorities concerning the movement of environmental pollutants in Arctic marine food chains and their effects on marine ecosystems in the Arctic, including possible consequences for human beings. The purpose of the programme is to help the authorities to obtain a satisfactory pool of basic knowledge to:
The knowledge acquired is primarily envisaged to cover the
needs of environmental management. It should also fill important gaps in knowledge held by
the fisheries and health authorities. 1.3.2 Demarcations and amplifications of the terms of reference Geographically, the programme will mainly be directed at problems in Norwegian areas, i.e. western parts of the Barents Sea. Studies of the transport and effects of contaminants in food chains in the Kara Sea and Pechora Sea will only be included to the extent that they will provide significant information pertaining to Norwegian interests in the Barents Sea. Information currently available on observed levels in organisms and the physical environment will form the basis for designing studies of transport and effects in Arctic food chains. Mapping of levels will only be included when it forms a direct part of the effect and transport studies, or to reveal potential, new environmental problems as a basis for setting up priorities in a long-term monitoring programme. Screening. Limited investigation to clarify whether or not a problem exists. A distinction is drawn here between screening and a basic investigation that is the first step in long-term monitoring (i.e. reference from monitoring data). Arctic organisms comprise organisms at every trophic level in Arctic marine food chains. The programme will focus upon selected species chosen for their usefulness as indicators for monitoring work and their possible significance for transferring contaminants to man.. Contaminants (environmental pollutants), here, will include persistent, polluting organic substances, radionuclides and heavy metals. The programme will focus upon a selection of components and substances made on the basis of a survey of what is known about their properties, sources, bio-accumulation and effects on organisms (see Chapter 2 Status of knowledge). To assess radiation doses and effects of radionuclides, emphasis will be put on accidental emissions. Transport in the food chains. The working group believes that the concept of 'transport' must be interpreted more widely than that of accumulation. Transport, here, means the fundamental processes for assimilation, flow and exposure of contaminants within the food chains, perhaps including a calculation or estimation of doses in the food chains (load and/or exposure). It does not include the physical transport of contaminants by ocean currents, ice, etc., which is being covered by the programme "Transport and fate of contaminants in northern seas". Effects. The programme will cover biological effects on cellular processes and at the level of organisms, thus forming the basis for assessing effects on populations and ecosystems. Cost limits for the programme have not been stated. The working group has therefore drawn up a set of priorities for use when selecting projects. Co-ordination with other programmes. To avoid doing work twice and to ensure that the projects are relevant to the needs of management, the programme will be co-ordinated with projects run under the auspices of AMAP, the Research Council's programme for ecotoxicology, the Joint Norwegian-Russian Environmental Commission, the ecotoxicology programme run by the Polar Environment Centre, the programmes of the Institute of Marine Research (particularly its working group for transport and effects of contaminants in marine food chains), the monitoring programme run by the Norwegian Radiation Protection Authority (particularly its work connected with the status report for AMAP), Nordic Co-operation on Nuclear Safety and the work of the Norwegian Polar Institute's ecotoxicology programme. A major objective when carrying out this co-ordination effort will be to identify important fields and projects that are not being realised or funded through ongoing programmes (as of 1.1.1997). The implementation of the programme must be viewed in the context of existing environmental monitoring in northern seas and projects will be given priority with this and future environmental monitoring in mind. The Institute of Marine Research at the Directorate of Fisheries is operating a long-term environmental monitoring programme for the Barents Sea based on some permanent traverses in combination with periodical regional coverage. The measurements along the traverses, taken 1-6 times annually, comprise salinity, temperature, nutrient salts, phytoplankton and zooplankton. The regional coverage also includes measurements of radionuclides, organic contaminants and heavy metals in biota and sediments. As part of the AMAP work, the Norwegian Polar Institute is undertaking environmental monitoring of seabirds and terrestrial and marine mammals in the northern regions, a task envisaged to be implemented every five years. The State Pollution Control Authority has initiated a number of short-term programmes operated through AMAP to fill existing gaps in our knowledge regarding the status of contaminants. Through its "Action plan for contaminated sediments", the Authority is mapping contaminants in harbours in North Norway. The Joint Assessment and Monitoring Programme (JAMP) likewise continually monitors a large number of coastal stations north of Lofoten, also taking in heavy metals. The Norwegian Radiation Protection Authority in co-operation with the Institute for Energy Technology, the Institute of Marine Research and the Directorate of Fisheries carries out an annual control programme to measure radioactivity in fish, whales, shrimps, kelp and sea water. The proposed programme must also be kept informed about, and, if necessary, be co-ordinated with, the effort being made under the auspices of the Directorate for Nature Management to develop a national programme to monitor biological diversity. A great deal of the mapping of various types of contaminants in biota in the Arctic marine environment has focused upon organisms that are at a high trophic level (fish, seabirds and mammals). Information about concentrations in biota at lower trophic levels is largely lacking. Such information is valuable if we are to understand the scale of the transport of substances from one link to another in the food chains. Adequate knowledge is also lacking concerning the exchange of contaminants between abiotic components (e.g. sediments) and biota. The primary production along the ice margin and the Polar Front is of great significance for the life in the Barents Sea. We lack knowledge about the importance of the primary producers with regard to assimilation of pollutants into the food chains. Knowledge is lacking about the turnover (metabolism) of contaminants in marine biota, and also about how cellular metabolic processes are influenced by climatic conditions and the huge seasonal variations prevailing in the Arctic. We also lack information about possible interacting impacts (antagonistic, synergistic, additive) of various pollutants and physical stress. Important general problems
Knowledge about the concentration of organic contaminants in the marine environment in the Norwegian part of the Arctic varies from one substance to another. However, on the whole, it is considered satisfactory as a basis for future monitoring. An important exception is toxaphene, and a basic study on fish, seabirds and marine mammals is recommended to acquire a better impression of the toxaphene load in the Barents Sea. Understanding the bio-availability, assimilation and transport of organic contaminants in biological systems is closely linked with knowledge about lipides and the physiological turnover of lipides in organisms. This is especially important in the Arctic where lipides play a very major role in processes which regulate the turnover of energy by organisms. Information about the dynamics of lipides in organisms will be of prime importance for enhancing our knowledge of the turnover and effects of organic contaminants. This also includes studies of how metabolism is influenced by energy conversion and low temperatures. Existing knowledge in these fields is considered inadequate. The last couple of years have seen a great deal of international research activity on problems linked with the biological effects of organic contaminants, and much of this has been directed at effects on reproduction. Even though knowledge has expanded, our understanding of the effects which such substances have on organisms in natural ecosystems is still extremely limited. Exceptionally high levels of some organic pollutants (e.g. PCBs) have sometimes been observed in predators uppermost in Arctic food chains (seabirds and marine mammals) and, based on studies in temperate regions, the possibility cannot be excluded that the levels observed have led to, or can lead to, biological effects. Few effect studies have, however, been performed on organisms living in the Arctic, and knowledge is therefore considered to be highly inadequate. The need to implement studies of effects on individuals (biochemical and physiological effects) which may lead to ecological effects (on population and ecosystem levels) is great. In view of the overall knowledge about the occurrence of organic pollutants in biota in marine areas in the Arctic, the working group believes a special need exists for improving our basic knowledge concerning transport, assimilation, bio-availability and effects of PCBs. Moreover, it is considered extremely important to become capable of linking biological and physiological effects with ecological effects. To achieve this, it will be valuable to have the possibilities and limitations of various ways of monitoring biological effects tested. Important problems
Radioactive pollution in the northern seas mainly represents a potential problem in the event of accidents and major emissions from sources in north-western Russia and western Europe (Sellafield, Dounreay, La Hague). Models are a valuable tool for enabling us to appraise a potential contamination scenario, but the quality of the calculations on which they are based depends upon the parameters and processes involved being well determined. In this connection, there is a need for more knowledge about the assimilation and transfer of radionuclides in the food chains and to what extent these processes are influenced by various physical and chemical factors. Viewed in the light of the immense value of the Barents Sea fish resources, it is specially important to obtain more information, for all the most important fish species in the area, about the factors that concentrate the contamination and which factors influence this (chemical state, assimilation from water into the food chains, etc.). It is known that the concentration factors vary greatly, and indications are present that they may in general be somewhat higher in northern seas than the standard values cited by the International Atomic Energy Agency. It is desirable to get more information about radiation doses to different biota as a consequence of radioactive contamination. This can help to identify which ecosystems, species or developmental stages are most vulnerable if a serious contamination situation arises. Data on assimilation and transfer in the food chain will form the basis for model calculations here, too. Sensitivity analyses linked with models will also identify and quantify key parameters and processes that have the greatest importance for the exposure of human beings and biota. In connection with planning the future monitoring of the northern seas, it is desirable to have the key parameters which should enter into the monitoring programme identified. This can be done by developing models which describe processes linked with, among other things, the assimilation and transfer of radionuclides in the food chains. Data from field studies are needed to improve the basis for developing such models. More detailed studies of possibilities for simplifying analysis work connected with a monitoring programme are also desirable; for instance, analysing samples of kelp or other indicator species which concentrate radionuclides. The transuranic elements (plutonium and americium) are more intensively assimilated by shellfish and molluscs than by fish. Since they are radiologically more toxic than, for example, 137Cs, it is desirable to know more about their assimilation by and transfer to these species. Tsjernaya Guba, a fjord at the south end of Novaya Zemlya, is heavily contaminated by plutonium due to underwater testing of atomic weapons. Benthic animals and animals at low steps in the food chain contain the highest concentrations. It is desirable to study possible biological effects of radiation in the field, and this may perhaps be possible here. Studies of biological effects of radioactive substances otherwise usually have to be performed in the laboratory. Suggestions for problems which should be clarified
Based on what is known of heavy metal contamination in Norwegian Arctic waters, there seems to be no acute need to fill gaps in our knowledge regarding the state of the area. As far as can be judged, these are among the least contaminated areas in the Northern Hemisphere, even though local exceptions exist in coastal and fjord districts. The exceptions are, however, located outside the Norwegian zone, and it is assumed that they will not significantly affect Norwegian areas, either. Nevertheless, the general public directs considerable attention towards heavy metals (particularly Cd, Hg and Pb), especially regarding their content in foodstuffs. Changes in the emission situation may lead to changes in heavy metal contamination in Arctic seas. An example of this is that claims have recently been put forward in the media that industrial effluent from the Kola region may have led to an enhanced influx of heavy metals to neighbouring Norwegian waters. Likewise, increasing petroleum activity on both the Norwegian and Russian sides will lead to greater heavy metal contamination. There is therefore a need for suitable, routine monitoring of heavy metals in Arctic waters to ensure that changes in the environmental situation are discovered at an early stage. The levels of heavy metals are low in the Arctic marine environment, and there is little evidence to suggest that existing concentrations will have measurable effects on the plant and animal life. Possible exceptions are coastal districts where emissions from mining and industry are present. Owing to the lipophilic properties of methyl mercury, mercury stands out as the principal heavy metal assumed to constitute a potential problem in the Arctic, and it is first and foremost this metal that has the potential for giving measurable effects on animal life there. To create the best possible basis for future monitoring, it is important to clarify a number of aspects regarding the occurrence and transport of heavy metals in Arctic food chains. Attempts should also be made to identify a set of indicator organisms for heavy metal contamination, and techniques should be put in place for measuring the effects of heavy metals on marine biota. In the last-mentioned context, special emphasis should be placed on testing methods that are capable of providing early warning of any changes in the environmental situation. A future monitoring programme must be founded on measurements of the content of contaminating substances in the environment, but in an ecological context the clarification of exposure, tolerance limits and effects is the most important goal. The methodology for investigating and monitoring the state of the environment, i.e. measuring the content of heavy metals in sediment, water and biota, is for the most part well developed. However, no fully tested methods of monitoring effects on the environment exist, and we lack knowledge about the connection between exposure and effect. There is a general lack of knowledge about the movement of heavy metals in Arctic marine food chains. More knowledge about bio-accumulation is essential both for saying something about the long-term effects and to be capable of setting up an ecologically relevant monitoring programme for heavy metals. Relevant problems
The proposed activities are ranked in priority to meet the requirement that the programme will help to establish a satisfactory platform of knowledge to:
With this as the background, the working group has elected to put priority on the following main fields (not in ranked order):
The previous chapters have reviewed the current state of knowledge regarding the occurrence, transport and effects of contaminants in the northern seas. For each group of substances, this review has resulted in a non-ranked list of gaps in knowledge that should be filled. Based on the problems that have been identified, the following sections describe problem fields on which projects should be carried out in connection with the preparation of a co-ordinated and comprehensive monitoring programme for the northern seas. This should be co-ordinated with ongoing monitoring. The fields and projects must be specified, in part on the basis of the status report from AMAP, and put together to form a programme that can ensure the co-ordination of sampling, analyses, experiments and so on. The ultimate selection of projects and their order of priority will be decided by a working group (see Chapter 5 - Administrative activities). Results which emerge as the work proceeds will be directly utilised for planning the long-term monitoring of contaminants in the northern seas. The group therefore proposes that work on a monitoring strategy is included as an integrated part of the programme. Monitoring of various contaminants is usually performed by analysing the substances in water, sediment and biota. Although good methods have been evolved for analysing radionuclides and heavy metals, there is still a need to perfect analysis techniques for the determination of certain organic contaminants, such as toxaphene. Better and more standardised techniques for simplifying sampling and analysis work are also required, for instance with respect to some radionuclides, including 137Cs, 60Co and 19Tc, which become concentrated in kelp, thus making their recognition easier. Analysis of transuranic elements in sea water requires large samples. It is desirable to investigate the value that may be derived from indicator organisms in connection with simplifying sampling and analysis. By using 'on-line' fractionation methods, monitoring programmes will also contribute information on chemical states. There is also a need to standardise the sampling of higher animals (fish, birds and mammals). Large variations in the concentration of organic contaminants have proved to exist in relation to the time the sample is taken and where on the animal the sample is obtained. Techniques for effect monitoring have not been fully developed. The application of biomarkers, as well as possible limitations in their use, to demonstrate biological effects of contaminants under Arctic conditions should be investigated in greater detail (through a combination of laboratory and field studies). This can decide whether these techniques can be used in future environmental monitoring. This work also includes studies of the links between effects on biomarkers and ecologically relevant effects, such as those influencing reproduction.
4.2 Mapping new problem fields Routine monitoring of heavy metals, radionuclides and organic contaminants in Arctic waters is needed to ensure that changes in the environmental situation are discovered at an early stage. However, we lack a full overview of all the substances that can be found in the environment, and their concentrations. This is important basic information for making priorities in a future monitoring programme, and concerns, for example, the occurrence of toxaphene. This compound has been found in high concentrations in peak predators in Canada. The few analyses performed in Norwegian areas suggest that toxaphene may also be a problem here. Investigations should be carried out to clarify whether this is the case. 4.3 Assimilation and transport in food chains Radionuclides, heavy metals and organic contaminants are assimilated by and transferred in Arctic marine food chains. Organic contaminants and certain heavy metals will chiefly accumulate in peak predators in the Arctic, such as seabirds, seals and polar bears. It is important to find out how this accumulation takes place. It concerns both transfer from water and sediments to plankton and micro-organisms, and between the various trophic levels in marine food chains. Knowledge about processes controlling assimilation in the lower links in the food chains is fundamental for being able to assess the risks associated with exposure to contaminants for species at higher trophic levels. Together with studies of particle transport and sedimentation, food chain studies will provide better insight into processes in the entire water column. This will help to further the understanding of both biotic and abiotic processes, which play a role for the transport of contaminants and their fate in the Barents Sea. An understanding of the assimilation and transport of organic contaminants is closely linked with knowledge about lipides and their dynamics, and such measurements should form part of the transport studies. In the event of a major emission of radioactive substances into the marine environment, the greatest concern will probably surround damage to fisheries, i.e. that the content of radioactivity in fish approaches the tolerance limits. It is also important to be able to calculate doses to human beings and thereby estimate the impacts on health in connection with, for instance, eating fish and other marine food. Very little is known about the relative significance of various factors affecting the assimilation and transfer of radionuclides in food chains, and special attention should be given to the significance of the chemical state of the radionuclides for assimilation in food chains, the assimilation mechanisms, the importance of diet composition and differences between species, as well as the significance of light conditions, temperature and salinity. More information about these aspects will improve predictions of radiation doses to people following an emission, and will be used to calculate doses to a variety of marine organisms, including fish. The working group advocates the undertaking of a co-ordinated field investigation and cruise to acquire better data on these aspects regarding organic contaminants, radionuclides and heavy metals. Information about the assimilation and transfer of contaminants in food chains provides the basis for developing models, performing vulnerability analyses, studying exposure and biological effects, and making environmental impact analyses for the environment and human beings. More information about these factors will therefore be extremely useful in connection with the drawing up of a monitoring strategy. 4.4 Exposure and effects of contaminants Owing to the enrichment of organic contaminants through the food chain it may be assumed that polar bears and other animals at the top of marine food chains in the Arctic will be specially vulnerable to negative effects. The effects of contaminants on organisms living in polar regions are still inadequately known. The sex and stage of sexual maturity, age, diet and temperature (particularly for cold-blooded animals) are important natural factors affecting assimilation, distribution, metabolism, liberation and effect of alien substances. This often makes it difficult to distinguish natural variations from the effect of environmental pollutants. Laboratory trials under controlled conditions are therefore an essential supplement to field investigations for studying the effects of contaminants. Special interest is attached to possible ecologically relevant effects on reproduction. Such effects should be first and foremost studied in peak predators and fish. There will be a need to test and combine different techniques for proving biological effect in order to be able to make the necessary links between load and effect at different levels. As mentioned previously, mercury in the form of methyl mercury, stands in a class by itself when it comes to effects on Arctic animal life. Carnivorous fish contain more mercury than small herbivorous fish, and the content is higher in fish which eat other fish than in those which eat zooplankton. The mercury content also increases with the age of the fish (Ruiter, 1995). Hence, we can, theoretically, expect the greatest impacts in mammals which directly or indirectly eat large fish species high in the food chain, primarily seals and polar bears. Species living by eating filter-feeding animals, like shellfish, in areas with particularly large influxes of heavy metals may also be suitable indicator species. To investigate the possibility of environmental consequences linked with potential radioactive contamination, it is necessary to study the distribution of radiation doses to different organisms, and also to identify sensitive species and stages. Dosimetric models for biota also need to be evolved, based on available data from the literature and field work. Here, special account must be taken of external radiation from contaminated sediments, which are the source of a significant portion of the radiation doses for benthic organisms. The level of radioactivity will be low in Arctic regions, particularly in fish, and it will therefore be impossible to identify any effects related to radiation doses. However, sediments close to dumped radioactive waste in the Stepovogo and Abrosimov fjords on Novaya Zemlya and the nuclear testing areas near Tsjernaya Guba are appreciably contaminated. Benthic animals from these sediments will therefore be the only relevant organisms that can be used in effect studies, apart from in the laboratory. Implementation of the projects will be co-ordinated to make the work most efficient. This will partly take place through extensive co-operation between the participating institutions (establishment of project groups) and organisation of joint collecting of samples in the field. Budget proposals for each sub-objective in this programme are given below. Separate budgets are set up for, respectively, "Monitoring techniques" and "Mapping new problem fields" ("Screening investigations"), whereas two budgets are set up for each of the sub-objectives "Assimilation and transport in marine food chains" (pelagic and benthic) and "Effects on indicator species" (peak predators and fish). Finally, a budget is given for programme administration, including reporting and evaluation, as well as an integrated project for drawing up strategy and recommending methods for the long-term monitoring of these waters.
For more details about the individual budgets, references are
given to earlier text in the programme proposal. The Institute of Marine Research and the
Norwegian Polar Institute now have the prime responsibility for monitoring in northern
regions, and will therefore play key roles in the task of gathering data. Mapping new problem fields (Screening investigations) Assimilation and transport in food chains Assimilation and transport in food chains Effects on peak predators (polar bears and birds) Effects - fish (laboratory experiments) Effects - benthic animals (radionuclides) |
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