Report No. 37 to the Storting (2008-2009)

Integrated Management of the Marine Environment of the Norwegian Sea— Report No. 37 (2008 – 2009) to the Storting

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9 Goals and knowledge-based management

9.1 Goals for management of the Norwegian Sea

The Government has decided on a set of goals for the management of the Norwegian Sea, which include both general objectives concerned with value creation and coexistence between industries, and more specific goals for managing biological, geological and landscape diversity, combating pollution and ensuring safe seafood. The Government’s general objectives are set out in Chapter 2, and more specific goals for the Norwegian Sea are listed below. These objectives and goals, together with the assessment of cumulative environmental effects in the Norwegian Sea, form the basis for the overall assessment of the need for measures and tools presented in Chapter 10. The goals will be followed up by the authorities in the relevant sectors. In order to measure progress systematically, the Government will establish a system for monitoring the state of the environment and environmental risk by means of indicators, reference values and action thresholds.

The Government’s overall objective is to ensure that management of Norwegian sea areas is based on knowledge of ecosystem structure and functioning and of how this is affected by human activities. Gaps in our knowledge could result in political objectives and priorities that are decided at random and are not cost-effective. More knowledge is also needed for assessing progress towards the goals.

Knowledge of the Norwegian Sea is being built up through research, surveys, environmental monitoring, reporting and other knowledge-related activities in the relevant sectors and institutions. The knowledge base for the present management plan is extensive. Our knowledge about fish stocks is based on over 100 years of research and monitoring of living marine resources and the marine environment, and Norway has been transporting goods and passengers by sea for centuries. We also have data from comprehensive surveys, studies and monitoring in connection with petroleum activities in the area. Nevertheless, there are still a number of gaps in our knowledge about ecosystems in the Norwegian Sea. This chapter provides an overview of our current knowledge about the most important fields covered by the management plan. It is not comprehensive and focuses on the main knowledge gaps that need to be filled.

Objectives for the protection and sustainable use of the Norwegian Sea

Management of biological, geological and landscape diversity

  • Management of the Norwegian Sea will ensure that diversity at ecosystem, habitat, species and genetic levels, and the productivity of ecosystems, are maintained. Human activity in the area will not damage the structure, functioning or productivity of ecosystems.

Management of particularly valuable and vulnerable areas and habitat types

  • Activities in particularly valuable and vulnerable areas will be conducted in such a way that the ecological functioning and biodiversity of such areas are not threatened.

  • Damage to marine habitats that are considered to be endangered or vulnerable will be avoided.

  • In marine habitats that are particularly important for the structure, functioning and productivity of ecosystems, activities will be conducted in such a way that all ecological functions are maintained.

Species management

  • Naturally occurring species will exist in viable populations and genetic diversity will be maintained.

  • Management of living marine resources will be based on the principles of sustainable harvesting.

  • Species that are essential to the structure, functioning and productivity of ecosystems will be managed in such a way that they are able to maintain their role as key species in the ecosystem concerned.

  • Populations of endangered and vulnerable species and species for which Norway has a special responsibility will be maintained or restored to viable levels. Unintentional negative pressures on such species as a result of activity in the Norwegian Sea will be avoided.

  • The introduction of alien species through human activity will be avoided.

Marine protected areas in the Norwegian Sea

  • A number of marine protected areas will be established in the Norwegian Sea by 2010 as part of the OSPAR network of Marine Protected Areas.

  • A representative network of marine protected areas will be established in the coastal and sea areas in the Norwegian Sea at the latest by 2012.

Pollution in general

  • Releases and inputs of pollutants to the Norwegian Sea area will not result in injury to health or damage the productivity of the natural environment and its capacity for self-renewal. Activities in the area will not result in higher levels of pollutants.

Hazardous substances and radioactive substances

  • The environmental concentrations of hazardous and radioactive substances will not exceed the background levels for naturally occurring substances and will be close to zero for man-made synthetic substances, and releases and inputs of hazardous or radioactive substances from activities in the Norwegian Sea will not cause these levels to be exceeded.

Operational discharges

  • Operational discharges from activities in the area will not result in damage to the environment or elevated background levels of oil or other environmentally hazardous substances over the long term.


  • Litter and other environmental damage caused by waste from activities in the Norwegian Sea will be avoided.

Safe seafood

  • Fish and other seafood will be safe and will be perceived as safe by consumers in the various markets.

  • Activities in the Norwegian Sea will not result in higher levels of pollutants in seafood.

Acute pollution

  • The risk of damage to the environment and living marine resources from acute pollution will be kept at a low level and continuous efforts will be made to reduce it further. Activities that involve a risk of acute pollution will be managed with this objective in mind.

  • Maritime safety measures and the oil spill response system will be designed and dimensioned to effectively keep the risk of damage to the environment and living marine resources at a low level.

9.2 Monitoring and performance

Ecosystem-based management of human activity in the Norwegian Sea must be based on regular assessments of trends in the state of the ecosystem in relation to the goals of the management plan. Through a system for monitoring ecological quality, the management authorities will be warned of changes that require action. However, choosing the necessary and appropriate measures requires information that clearly distinguishes between anthropogenic pressures and changes that occur independently of human activity. The system for monitoring the state of the ecosystem in the Norwegian Sea will be coordinated with the integrated system for monitoring the state of the ecosystem that has been developed as part of the management plan for the Barents Sea–Lofoten area, and will be based to some extent on experience of the Barents Sea–Lofoten system. The indicators, reference values and action thresholds selected for the new monitoring system will have to be appropriate for the conditions and monitoring needs in the Norwegian Sea, but it would be an advantage to have as many common indicators as possible for all sea areas so that trends can be compared more easily. The question of whether more specific indicators are needed for some of the particularly valuable and vulnerable areas should also be considered. Action thresholds will be set in cases where indicators reflect the impacts of human activity. The system of indicators must also be adapted to the EU’s Marine Strategy Directive so that trends in the Norwegian Sea can be evaluated in a European context.

9.2.1 Monitoring of selected indicators in the Norwegian Sea

The elements of the monitoring system for the Barents Sea–Lofoten area are described in the management plan for this area and are also applicable to the monitoring system for the Norwegian Sea that is proposed in Appendix 2.

As in the management plan for Barents Sea–Lofoten area, the pollution indicators and action thresholds have been chosen with a view to measuring performance in relation to biodiversity, pollution and seafood safety goals. The choice of indicators is determined by their role in the ecosystem, whether they are feasible in practice, and their relevance to ecosystem management and in relation to Norway’s international obligations.

Species that are important in a monitoring system for the Norwegian Sea include Norwegian spring-spawning herring, blue whiting, mackerel and demersal species such as Greenland halibut, ling and tusk. A number of seabird species, such as kittiwake, common guillemot, puffin, common eider and shag, are also useful as indicators, since they occupy different ecological niches and have different ecological functions, and can therefore serve as indicators of different kinds of changes in ecosystems. Identifying good indicators for monitoring the status of benthic fauna will be a difficult task, and attention will be concentrated on species that are vulnerable to physical disturbance. Pollution indicators (for heavy metals, persistent organic pollutants, radioactivity and so on) will be based on those used in the Barents Sea–Lofoten management plan. The pollution indicators are intended to provide information on current pollution levels and trends in pollution and their possible impacts on seafood safety. Spring-spawning herring, Greenland halibut and hooded seal are proposed as replacement indicators for the northernmost species in the Barents Sea–Lofoten plan.

Data for many of the proposed indicators for the Norwegian Sea are already part of long time series that are updated annually. However, for other indicators, new time series will have to be started or existing data reorganised.

Many of the indicators will need a certain amount of development, and these are indicated in Appendix 2. Generally speaking, there is a need to further develop and refine indicators and action thresholds for seabirds and many mammal species. Data and data series already exist for these species, but have not previously been used in a management context or for setting reference values. This must be done by experts in consultation with the authorities. We need to know much more about pollution in the areas beyond the continental shelf in the Norwegian Sea, and a review must be conducted of the risk factors and the corresponding necessary indicators and action thresholds. Appendix 3 lists the current and proposed pollution indicators and recommended sample types. Long time series should be built up for monitoring pollutants. Aggregate indicators should be tested to identify combinations of indicators that taken together provide a clearer picture and/or help the management authorities to identify changes in ecosystem status.

The work on environmental quality monitoring in OSPAR, ICES and the management plan for the Barents Sea–Lofoten area has shown that it takes time to develop good indicators. This applies both to the selection and description of indicators and to how they should be used. Thus the indicators proposed in this report are not intended to be final but to be the first step in the development of good management tools for the Norwegian Sea.

9.2.2 Implementation

The monitoring system for the Norwegian Sea, like that for the Barents Sea–Lofoten area, will be built on existing and planned monitoring programmes and will be in line with Norway’s international obligations. This will ensure that existing time series can be continued and that future research and monitoring needs are taken into account in the ongoing development of the management plan. New monitoring programmes should as far as possible be carried out within the framework of existing programmes. The Marine Pollution Monitoring Programme, which monitors inputs of oil and environmentally hazardous substances into sea areas, is based on this principle and will in the long term provide the necessary data on pollution for all Norway’s management plan areas.

9.3 Priority knowledge areas

Although in general a good deal is known about the ecosystems in the Norwegian Sea, there are still knowledge gaps in certain areas. The following is an outline of the most important areas where these gaps need to be filled:

  • ecosystem structure and functioning, for example interactions between habitat-forming species, predators and prey,

  • ecosystem services, for example climate regulation, food production and water purification,

  • the impacts of human activities, separately and together, on different parts of the ecosystem,

  • the geographical distribution and recruitment mechanisms of herring, blue whiting and mackerel,

  • variations in seabird populations and possible relationships with human pressures, food supplies and climatic conditions,

  • information about the physical and chemical environment of the seabed and associated habitats and biodiversity, including the presence of particularly valuable and vulnerable habitats, for example from surveys under the MAREANO programme,

  • knowledge of species and population diversity in the Norwegian Sea, including genetic diversity in selected populations,

  • surveys, studies and monitoring of alien marine organisms,

  • the mechanisms behind changes in wind patterns, ocean circulation and distribution of water masses in the Nordic seas in order to obtain more reliable predictions about the impacts of climate change,

  • trends in climate change and ocean acidification and the impacts of interactions between these processes on ocean ecosystems, with a focus on particularly vulnerable groups of organisms, groups of particular importance in food chains, commercially important species and interactions between all groups in food chains,

  • potentiating effects of interactions between hazardous substances and between hazardous substances and other factors such as ocean acidification and climate change,

  • effects of seismic activity on fish, including gadids, and how to mitigate these effects,

  • impacts of human activity on seafood safety.

A more detailed overview of knowledge needs can be found in the scientific basis developed for the management plan.

9.3.1 Ecosystem structure and functioning

Our understanding of interactions between organisms in food chains needs to be improved. Ecosystem-based management requires knowledge of population sizes and production at lower levels in food chains, such as plankton, and their significance for higher trophic levels, such as fish, seabirds and marine mammals. We also need more knowledge about the key interactions between ecosystem components.

Generally speaking, we know too little about the ecological interactions between particular species and their prey, and between competing species in ecosystems. Large numbers of samples and data collected during research and monitoring cruises have not been processed, and this situation must be remedied so that the data can be used to address ecosystem-related issues. In cases where the underlying data are adequate, priority must be given to developing and refining models with a view to improving our understanding of ecosystems.

There are also gaps in our knowledge of the ways in which human activity affects the different ecosystem components and of the combined impacts of different pressures on individual species and on ecosystems as a whole. For example, climate change could result in changes in long-range transport of hazardous substances (due to changes in ocean currents and winds) or affect the environmental behaviour of such substances (degradation, uptake by organisms, etc.). Plants and animals that are already exposed to one or more environmental pressures may not tolerate further pressure. Sound ecosystem-based management therefore depends on ecosystem monitoring and adequate knowledge of the combined impacts of different pressures.

9.3.2 Individual species


Although in general we know much more about commercial fish stocks in the Norwegian Sea than about other animals and plants in the area, we have far more information about some fish species than others. We know most about Norwegian spring-spawning herring. Considerable research has been done on this herring stock and there are time series that date back at least 100 years. We know that climatic conditions and stock structure help to regulate its geographical distribution, a key factor in resource management, especially with regard to Iceland. However, we are still far from understanding the distribution dynamics of the stock and even farther from being able to predict its geographical distribution. Further statistical analyses and numerical simulation models are needed.

The underlying data on saithe, mackerel and blue whiting stocks are weaker than those for herring, capelin and cod in the Barents Sea. In the case of blue whiting it is especially important to understand the causes of the large variations in recruitment to the stock in recent years.

In the last few years a good deal of research has been done on Greenland halibut and redfish, but we know less about stocks that are not much used commercially, such as tusk, ling, halibut and greater argentine, and also about mesopelagic fish, sharks and skates.

There is a pressing need for more knowledge about the interactions between the ecologically and commercially most important fish stocks, and between fish and other species in the food web at both higher and lower trophic levels. We also need to understand more about the impacts of climate change on recruitment and of fishing on stock structure (fisheries-induced evolution).

Distribution, numbers, condition, reproduction and recruitment should also be monitored for stocks other than those of commercial value, since such knowledge is essential to our understanding of ecosystem functioning and thus for ecosystem-based management. An ecosystem approach also requires knowledge about the distribution, habitat use and food habits of fish stocks that are not harvested commercially.

Figure 9-1.EPS Shoal of saithe

Figure 9-1.EPS Shoal of saithe

Source Photo: Erling Svensen

Food safety is important, not least in relation to fish exports. There is increasing international emphasis on food safety, and common limit values have been set for a number of substances in seafood. A thorough survey of hazardous substances should be conducted for all species used for food in Norway and for all those that are exported. A good deal has already been done in this area, and major surveys of Greenland halibut and mackerel are being conducted. Further surveys should be made, for example of cod and saithe, which are the most important exports from capture fisheries.

Marine mammals

We do not know enough about the seasonal diet of marine mammals, the competitive relationships between them and whether they have strict dietary preferences or are more adaptable to variations in food supply. We also need to know more about the spatial distribution and ecological roles of marine mammals in the management plan area.

The knowledge base for migratory species of marine mammals should be expanded and updated. In order to understand their migration routes and the impact of environmental pressures, we need more information about stock components, recruitment, migration patterns, main areas used on migration and for overwintering, spatial distribution at different times of year, and the seasonal dietary and habitat requirements of different species. This will require both monitoring and research.

There is also a pressing need for quantitative data on the impacts of the strength, trends and temporal variations in climate change on biological production and trophic interactions at all levels in the food web up to marine mammal level, from primary production to marine mammal food supplies, reproduction and survival.


Although the large seabird colonies have been extensively monitored and studied for many years, integrated monitoring of seabirds in Norway only began with the introduction of the SEAPOP (SEAbird POPulations) monitoring programme. Adult survival, reproduction and food preferences are being studied at Røst, Sklinna and Runde, which are key locations for seabirds.

Figure 9-2.EPS Cormorants

Figure 9-2.EPS Cormorants

Source Photo: Lars Løfaldli

More knowledge is required about the numerical, temporal and spatial distribution of seabirds, including distribution patterns, migration, variations in population density, population affiliation and total population size.

Most seabirds show slow maturation, are long-lived and have a low reproduction rate. This means that they are not very adaptable to changes in their habitat, and are therefore particularly vulnerable to anthropogenic pressures. More studies are needed on the direct, indirect and cumulative effects of such pressures on seabirds.

Corals and other benthic fauna

Much of the seabed of the Norwegian Sea has not been studied, and our knowledge of the biological, chemical and physical environment is inadequate. We know little about which habitats are to be found where on the seabed, and even less about benthic species. This means that surveys of the physical, chemical and biological seabed environment are needed. Certain areas of the seabed have been surveyed in connection with planning and impact assessments related to petroleum activities, for example on the mid-Norwegian continental shelf, including the continental slope and the Vøring Plateau, and in deeper waters west of Svalbard, and the data from these surveys are valuable inputs to the knowledge base.

Figure 9-3.EPS Corals

Figure 9-3.EPS Corals

Source Photo: Institute of Marine Research

Monitoring programmes are needed for example for habitats that are particularly vulnerable or are expected to be affected by climate change and ocean acidification, such as coral reefs, cold seeps and black smokers. Research on benthic ecosystems and habitat types should also be intensified. Two particularly important research areas are the separate and combined impacts of anthropogenic pressures, climate change and ocean acidification; and ecosystem services, including their importance for biodiversity, the resource base and climate regulation.

Introduction of alien species into the marine environment

In 2007 the Norwegian Biodiversity Information Centre published a Black List of alien species in Norway and in this connection, ecological risk analyses have been conducted for a selection of alien species. The Black List contains 44 marine species. Activities such as international trade and transport are contributing to the spread of alien species.

At present no alien marine species are being systematically monitored apart from the red king crab, which has not yet spread as far as the management plan area. The current system of surveying and monitoring marine ecosystems needs to be further developed with a view to revealing the presence of invasive alien species. There is also a need for more research on alien species that are now established in the wild, and their impacts on ecosystems.

9.4 Climate change and ocean acidification

Climate change and ocean acidification may have far-reaching impacts on ecosystems in the Norwegian Sea. However, the interactions between these factors are so complex, and the level of knowledge is still so low, that it is impossible to say with any certainty what these impacts will be. We therefore need to survey the current status, further develop the necessary long-term monitoring programmes, and give priority to research in cooperation with international research programmes. The focus should be on climate and acidification trends and the combined effects on ecosystems and the resource base, and on measures to address these problems.

Long time series obtained from monitoring and research are the most important basis for all climate research. The permanent monitoring transects across the Atlantic current are of key importance for monitoring in the Norwegian Sea, and data from the weather observation station M in the Norwegian Sea (the weather ship Polarfront, stationed at 66° N, 2° E) have provided an important supplement to oceanographic climate studies. As from 2010 the weather observation system at station M will be replaced by more up-to-date methods such as satellite monitoring. However, it is important to maintain the time series and ensure that oceanographic monitoring is also continued, and various alternatives are being considered. Extending the monitoring programme by establishing a number of monitoring stations along the front zones in the west and north to record interannual variations should also be considered. Studies should be conducted on the mechanisms behind changes in wind patterns, ocean circulation and distribution of water masses in the Nordic seas so that more accurate predictions can be made about the impact of climate change on the ocean climate. More knowledge is also needed on interactions between the impacts of climate change and acidification on individual species, groups of organisms and ecosystems, including on ecosystem dynamics. The focus should be on groups that are expected to be particularly vulnerable, such as calcifying species and early life stages, groups of particular importance in the food chain such as copepods, especially Calanus finmarchicus, commercial species, and interactions between these groups in food chains.

9.5 Pollution

In order to assess the impacts of pollutants on species and ecosystems, we need a thorough knowledge of releases, levels and impacts of individual substances in the management plan area. It is also essential to know how the substances are metabolised or accumulate in the environment and in organisms, how substances interact, and how they are affected by other environmental changes such as climate change and acidification. A number of hazardous substances occur naturally in the sea, for example petroleum compounds, radioactive substances and heavy metals, which leach from the bedrock in many areas. It is important to know the natural background levels for such substances so that anthropogenic inputs and their impacts can be assessed. Climate change and acidification affect transport routes and the ways in which substances are metabolised and accumulate. Moreover, temperature and the chemical composition of seawater strongly influence the state in which substances are found and how they affect living organisms. There are large gaps in our knowledge in all these areas.

Using improved and coordinated methods for data collection, the Norwegian Marine Pollution Monitoring Programme has provided reliable general data on inputs of many hazardous substances into Norwegian sea areas, but there are still many substances for which no data have yet been collected. New measurements of the levels of hazardous substances in the various management plan areas will make a valuable contribution to the work, which is being coordinated by the monitoring group. The programme involves cooperation between all the authorities involved in the regular monitoring of sea areas, and the results will be used at national and international levels.

There is still some uncertainty about the long-term effects of discharges of produced water, but research and monitoring have not so far demonstrated any impacts at population level. However, investigations are being continued in the form of a separate research programme and other studies.

It is also important to be able to document levels of pollutants in fish and other seafood. A thorough baseline study of hazardous substances in Norwegian spring-spawning herring was conducted in 2008, and will be followed up with studies of other species. The international market for fish and seafood is particularly interested in this information. Some seafood species are also being used as indicators in the management plans, and pollution levels in these species will be measured under the Marine Pollution Monitoring Programme.

Textbox 9.1 The Marine Pollution Monitoring Programme

The objective of the Marine Pollution Monitoring Programme is to collect data on inputs of oil and other hazardous substances to the various management plan areas from all sources (local and long-range transport). The programme also monitors pollution status in these sea areas using the pollution indicators listed in the management plans and focusing on particularly valuable and vulnerable areas. The programme started in 2006, and the first phase involved surveys and modelling of inputs. The regular monitoring phase is starting in 2009, and involves measurement of levels of environmentally hazardous substances at a representative network of stations that cover the management plan areas. The network extends as far as the coast, which means that the data can also be used by the river basin district authorities in their management plans. This will make it easier to coordinate the plans for coastal and sea areas. All the main institutions responsible for monitoring programmes in Norway are taking part in this programme (Institute of Marine Research, Norwegian Institute for Water Research, Norwegian Institute for Air Research, National Institute of Nutrition and Seafood Research, Norwegian Radiation Protection Authority, in addition to the Norwegian Pollution Control Authority).

Figure 9-4.EPS Measuring stations for the Marine Pollution Monitoring Programme
 in the Norwegian Sea

Figure 9-4.EPS Measuring stations for the Marine Pollution Monitoring Programme in the Norwegian Sea

Source Institute of Marine Research, Norwegian Institute for Water Research, Norwegian Institute for Air Research, National Institute of Nutrition and Seafood Research, Norwegian Radiation Protection Authority, Norwegian Pollution Control Authority

9.5.1 Knowledge needs as regards seismic activity

Research on seismic surveys and their impacts on fish has been conducted in Norway in three periods: 1984–86, 1991–96 and 2002–04, most of it under the auspices of the Institute of Marine Research. Together with research findings from other countries, this has provided a knowledge base concerning seismic activity and its impacts on fisheries and biological resources that can be used for advising ministries, directorates and companies concerning the use of seismic surveys in exploration for oil and gas.

Seismic surveys at sea influence fish mainly through their sense of hearing. Scientists at the University of Oslo have been studying fish hearing for many years, and the research community here is now leading the way internationally in studies of how fish perceive sound and the ways in which different sounds and sound levels affect their behaviour. However, there are still major gaps in our knowledge in this field, especially with regard to the commercially important gadids. The sense of hearing in gadids is complex and we know that these fish can detect sonic acceleration and pressure, but we do not know which types of sound and sound levels trigger fright and flight behaviour in gadids. We need to know more about how fish perceive sound and which aspects of seismic waves trigger flight and avoidance behaviour in different species and groups of fish in order to understand the large-scale impacts of seismic activity on pelagic fish.

9.6 The risk of acute oil pollution

More knowledge is needed on the risk of accidents in petroleum activities and how technological advances and new organisational models in the industry affect the level of risk. Priority should be given to investigating how new organisational structures and models resulting from changes in the actors involved, globalisation, ICT advances and the introduction of integrated operations will affect risk levels.

When the lifetime of petroleum installations is extended, safety challenges arise as regards materials technology and continued operations. Priority should be given to further developing models to describe material degradation mechanisms and to developing technology and methods for monitoring technical status and management of technical and operational integrity.

There is also a need to develop technology for early leak detection in subsea installations, and technology and best practices for activity in high-pressure and high-temperature fields.

The Petroleum Safety Authority’s project «Trends in Risk Level» is an important tool for monitoring risk levels, and provides annual reports on trends in a number of risk indicators. The project should be further developed so that the annual reports on risk levels provide better information on the risk of acute pollution. This would allow negative trends to be identified at an early stage and provide the authorities and the industry with a better basis for assigning priorities in their efforts to avoid acute pollution.

Providing a more effective oil spill response system in the Norwegian Sea is not just a question of increasing material resources and manpower, it also means ensuring that equipment is adapted to the conditions there and improving expertise in oil spill response operations. The following areas are especially important in this connection:

  • improving our knowledge of the properties of the crude oil and oil products transported through the area,

  • developing technology that will make it easier to detect and monitor oil drifting on the sea in the dark,

  • developing technology and expertise for improving recovery of oil at sea in the dark and in icy waters, including the development of oil spill response equipment and alternative methods for dealing with the problem, including the use of chemical dispersants,

  • developing systems for temporary storage of oil and large quantities of waste,

  • increasing knowledge about the temporal and spatial distribution of ecological goods and services and their sensitivity to oil,

  • increasing the scope of oil spill response exercises during the darkest part of the winter,

  • developing effective methods and techniques for beach-cleaning.

9.7 The impacts of exposure to oil on fish eggs and larvae

The most serious impacts of oil and gas activities are considered to be those associated with major oil spills. There is a particular need for knowledge development with regard to the ways in which technological advances and new activities in the petroleum industry affect the nature and level of the risk of accidents. Further development of methods for overall risk assessment, assessment of environmental and social impacts of acute pollution, and indicators for monitoring risk trends in the petroleum sector are also needed.

We still do not know enough about the distribution, drift and survival of fish eggs and larvae. There are analytical tools that can be used to calculate environmental risk levels for fish eggs and larvae in the event of oil spills. However, experts disagree on whether individual results can appropriately be used in impact assessments and on the extent and significance of losses of eggs and larvae in a particular year class with regard to future recruitment to the stock, see Chapter 5.6.

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