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Regional case-studies: The Baltic Sea, and Indian Ocean

Regional cooperation in science: The Helsinki convention for the Baltic (Nikolaus Gelpke)
The Indian Ocean Marine Affairs Cooperation (IOMAC) (Hiran W. Jayewardene)

Nikolaus Gelpke and Hiran W. Jayarwardene

Regional cooperation in science: The Helsinki convention for the Baltic (Nikolaus Gelpke)

1. Introduction

On 22 March 1974 the seven States of the Baltic region - Denmark, Sweden, Finland, USSR, Poland, German Democratic Republic, and the Federal Republic of Germany - signed the Convention on the Protection of the Marine Environment (HELCOM) at its Secretariat in Helsinki, Finland. In the preamble of HELCOM, the parties recognize their responsibility "to protect and enhance the values of the marine environment of the Baltic Sea area for the benefit of their peoples," and that this "cannot effectively be accomplished by national efforts only but that close regional cooperation and other appropriate international measures aiming to fulfill these tasks are urgently needed."

The Helsinki Convention was the first regional treaty to cover land-based pollution sources and, in particular, to combat marine pollution from oil in the entire drainage basin, which is 4.3 times as large as the area of the Baltic Sea itself. Certainly the inspiration to initiate conventions for similar-sized semi-closed marine areas like the Red Sea, the Persian Gulf, the Mediterranean, and others, was drawn from the success of the intergovernmental action in protecting the Baltic Sea. This success was partly due to the well-developed organizational structure of Baltic marine science.

This chapter provides an overview of the reasons leading to this successful cooperation in the Baltic region. For a better understanding of the development of scientific and political cooperation in the region, a brief historical description, followed by the environmental aspects of the Baltic Sea, will be given. As an example of multilateral cooperation in the Baltic region, the Baltic Marine Environment Protection Commission will be described in more detail.

A comparison between the "Blue Plan" for the Mediterranean Sea and HELCOM may lead to new concepts in the Baltic region with regard to the existing new political and socio-economic situation in the eastern parts of the Baltic.

2. The Baltic region in its historical context

The Baltic has first to be seen in its historical perspective to understand the background of regional cooperation in science. This brief survey describes its social, political, and legal dimensions.

The history of human settlements in the Baltic basin dates back to the neolithic era - the Bronze and Iron Ages, when successive cultures were established on its shores and contacts with south European states existed. (O'Dell 1957)

The western and southern coastal Baltic areas have remained relatively stable since the tenth century. Slavic tribes had occupied most of the coastal area between the Elbe and the Vistula Rivers, while German Saxons on the southern coast had only a narrow foothold near Denmark. In the north, the western shores of the Baltic basin were inhabited by two Scandinavian tribes, the Swedes and Goths, while the Danes occupied their present area plus parts of the western and southern coastal Baltic areas. (Boczek 1989) The relatively stable political situation in this part of the Baltic region led to a strong economy, which has persisted to the present.

The southeastern and eastern parts of the Baltic region have a more complex human and political history. As an exception to the region, the Gulf of Finland was settled by Finno-Ugrics who migrated to the Baltic region from a region between the Ural and middle Volga Rivers. The southeastern part was settled by Baltic tribes belonging to the Indo-European family; the Livs, Lithuanians and Prussians. (Boczek 1989)

While the southern and western countries established their own states and had been converted to Christianity by the tenth century, the eastern parts of the region were occupied and subjugated by different states such as the German Order, and the Baltic tribes had been converted to Christianity by force. (Boczek 1989) Already in those times a cultural division was established between the Roman Catholic West and the Russian Byzantine East.

The quite stable situation of the western and southwestern parts of the region led, after a Viking period of three centuries, to the Hanseatic League in the fourteenth century, mainly controlled by the Germans. The Hanseatic League was a trading group in northern Europe, controlling the East-West trade of the time. This old tradition of East-West cooperation is very important for the understanding of scientific cooperation today, encompassing such different cultural and political systems.

The Hanseatic League was later controlled by Denmark and this country remained, after the decline of the "Hansa" in the fifteenth and seventeenth centuries, the dominant power in the Baltic region. Until World War II different states such as Poland, Sweden or USSR had the leading role in the control of the Baltic region through trade or military power. After both World Wars I and II, the region underwent political transformations. The most important political development was the rise of the USSR as the strongest Baltic state and the creation of the two German states, as well as the extension of the Polish coastline to more than 500 kilometres in 1945.

Today, the Baltic region is very highly populated and industrialized, economically intensively used, endangered by pollution and political insecurity. In the drainage basin of the 6 coastal States Finland, USSR, Poland, the Federal Republic of Germany, Denmark and Sweden - live approximately 71 million people, 51 per cent of whom are Polish, 16 million reside directly along the Baltic coast. (Jenisch 1991) These figures combined with the fact that the share of the Baltic region in worldwide industrial production has reached perhaps 15 per cent - testify to the stresses to which the marine Baltic environment has been exposed in its recent history. (Boczek 1989)

However, the lesson of Baltic history is, that even in a region where there are such different political and religious States, a stable political situation and old traditions in trade can lead to amicable cooperation among all of the littoral States. Only in times of war, when they try to achieve hegemony in the Baltic was cooperation never conclusive.

3. Environmental aspects of the Baltic region

The necessity to develop certain (scientific) multilateral agreements highly relevant to environmental concerns in the Baltic region, has to be explained by the specific marine environment of this region.

The Baltic Sea (417,000 km2) is one of the largest brackish-water areas in the world. Extremely shallow (mean depth 55 m, maximum 459 m) and geologically very young (formed 12,000 years ago), this semi-enclosed body of water (22,000 km3) provides an ideal experimental test bed for the proper understanding of marine environmental changes under the tremendous influence of man. It has not been recognized for about two decades that the Baltic Sea is seriously polluted, and various appraisals have become available. (Zmudzinski 1989) It is not only the influence of human activities, however, but also the specific environmental conditions in the Baltic Sea that have led to this situation.

The input of fresh waters into the Baltic Sea results in the stratification of the water column into two main layers, a surface layer (less saline) and a heavier bottom layer (more saline). The natural mixing of the water column by wind and currents influences only the upper layer. The Kattegat is divided through very shallow rises (18 m), where only specific climatic conditions allow the input of heavier salt water from the North Sea to enter the Baltic Sea. So the slow replacement time for 50 per cent of the water is about 8 years; and that for 90 per cent, about 25 years. The water exchange with the Baltic Sea is made more difficult by the fact that the Baltic Sea consists of several relatively deep basins, interrupted by shallow rises. The bottom layer remains less well mixed, and becomes progressively poorer in oxygen over a period of years due to biological activity. This natural phenomenon has been well known in the past, but increasing eutrophication of the Baltic Sea has resulted in a faster consumption of oxygen in the lower stratum of the bottom layer. The prevailing anaerobic conditions favour the growth of sulphate-reducing bacteria producing hydrogen sulphide, which is influencing the environment as a cell-poison and reductant which leads to the inhospitality of the stratum to its earlier inhabitants. (Babenerd and Meyerhöfer 1988) The last important salt-water input from the North Sea was in 1975-1976. As a result one could measure an increase of salinity and oxygen in the bottom layer, and as a consequence some animals could settle, but only temporarily.

Another consequence of the brackish character of the Baltic Sea is a minimal species diversity comparing with fresh water or ocean water. The increasing anoxia in the bottom layer enhances this fact even more.

The highly industrialized nations in the drainage basin of this small semi-enclosed sea cause not only eutrophication but also serious heavy-metal pollution. The increase of heavy metals in the bottom sediments where municipal and industrial wastes are being discharged (Kremling 1987) result in highly elevated copper concentrations of red and green algae and crustaceans; lead in red algae; and cadmium in the brown algae. Near the coast, mercury concentrations are, therefore, substantially high in the tissues of the commercially important herring. Levels of dichlorodiphenyltrichloroethane (DDT), polychlorinated hydrocarbons (PCBs) and oil (petroleum hydrocarbons) have been declining in recent years. However, higher values can still be found in coastal areas and near municipal centres.

In summary, eutrophication and the continued high input of toxic substances, particularly near industrialized centres, are of concern especially with regard to the relatively long period of renewal of the Baltic Sea water with water of the open ocean.

4. Multilateral cooperation in the Baltic region

The term "dominium maris baltici" is well known in history, science, and international law as the futile attempt of Danes, Germans, Poles, Russians and Swedes to achieve hegemony. There have been many attempts, but the political condition was never there. Since the early Middle Ages the law of free market and old trading traditions were stronger than any other power.

At the 6th International Geographical Congress held in London in 1895 Professor Otto Petterson of Sweden put forward a plan for international marine science cooperation for the Baltic, with special emphasis on the commercial aspect of fisheries. (Voigt 1986) These first endeavours to put forward a scheme for international marine science cooperation originated in the attempt to organize and optimize commercial cooperation. The congress recognized the scientific and economic importance of the results of recent research in the Baltic, especially with regard to fishing interests, and its opinion was that the survey of the area should be continued and extended to include the cooperation of the different nationalities. First in the field of scientific cooperation was the International Council for the Exploration of the Sea (ICES), founded in 1902.

Although issues of pollution have been recognized for a long time, it took half a century to create political circumstances allowing scientific cooperation in the region. At the start, multilateral cooperation among the seven Baltic littoral States was only possible after the official recognition of the German Democratic Republic by the Federal Republic of Germany in 1973 in the "Grundlagenvertrag." This treaty formed the prerequisite for the first multilateral convention the Baltic Fishing Convention of 1973.

The Convention on Fishing and Conservation of Living Resources in the Baltic Sea and the Belts was signed in Gdansk in September 1973. Under this condition, the International Baltic Sea Fishery Commission was established in Warsaw. In its preamble the parties to the Convention recognize the need for cooperation to preserve and increase the living resources of the Baltic Sea and the Belts. The Convention is an important legal instrument to provide a permanent system for resource monitoring, but a weakness of the Convention is that the Commission is powerless with regard to nonparties. It merely can "draw the attention" of nonparties to acts they may have committed that might have an adverse effect on the Baltic fishery resources. (Broms 1989)

Shortly after this first treaty the Convention on the Protection of the Marine Environment of the Baltic Sea followed in 1974. The Baltic Marine Environment Protection Commission (HELCOM) was established under the Convention in Helsinki. A detailed description and discussion of HELCOM is given in subsequent paragraphs.

Various other Conventions followed the first two:

- The Nordic Environmental Protection Convention of 1974

- The Final Act of 1975 on Security and Cooperation in Europe

- The Convention on Long-Range Transboundary Air Pollution of 1979

- The Convention Relating to the Non-Fortification and Neutralization of the Aaland Islands in 1921.

Besides intergovernmental agencies created by these Conventions there are two other organizational bodies - the Baltic Marine Biologists (BMB) established in 1968 and the Conference of Baltic Oceanographers of 1957 both independent non-governmental organizations (NGOs). The Baltic Marine Biologists was established by marine scientists of the Baltic region, mainly to elaborate and standardize methods for marine biological investigations and encourage close cooperation between the different scientific institutes along the Baltic coast. The early establishment of the NGOs in the Baltic region in 1957 and 1968 offered the chance for international cooperation long before intergovernmental agreements were possible. Therefore, independent non-governmental organizations are obviously a promising tool for peaceful scientific cooperation in a region where political security is still not yet established.

The existing multilateral agreements are an important contribution to political cooperation among the seven Baltic States. It is interesting to observe that the first environmental agreements were established, followed by political Conventions, both responsible for the benefit of the environment and security of the Baltic region. The development of environmental contracts appears to have influenced the trust among the various littoral States - not least among States belonging to the North Atlantic Treaty Organisation (NATO) and the Warsaw Pact. (Broms 1989) In other words, regional cooperation in environmental problems appears to enhance regional cooperation in the political area of the region. In a way, the environmental responsibility took over the stabilizing role of trade and commerce in earlier days.

5. Baltic Marine Environment Protection Commission

The basic foundation of cooperation among the Baltic coastal States is the "Convention on the Protection of the Marine Environment of the Baltic Sea Area" or the "Helsinki Convention." This Convention, adopted in 1974 and enforced since 1980, is the first international instrument to deal with different sources of pollution in respect to a given regime. (Ehlers 1988) The Convention led to the establishment of the Marine Environment Protection Commission (HELCOM), which serves as the executive body for the Convention.

Article III.1 of the Convention establishes a fundamental principle: "The contracting Parties shall individually or jointly take all appropriate legislative, administrative or other relevant measures in order to prevent and abate pollution and protect and enhance the marine environment of the Baltic Sea."

The basic provision governing scientific-technological cooperation is provided for in Article XVI: "The contracting Parties undertake directly, or when appropriate through competent regional and other international organizations, to cooperate in the fields of science, technology and other research, and exchange data as well as scientific information for the purposes of the present Convention."

A description and evaluation of activities under the Convention are given below.

A. Survey and research

Since 1979 the seven littoral States of the Baltic region are carrying out a "Baltic Monitoring Programme" under the guidelines of HELCOM. Measurements of the environmental quality are carried out regularly at stipulated stations in the Baltic Sea. A weakness of the monitoring programme is the limitation of survey to the central Baltic Sea, with no monitoring stations close to estuaries or dumping areas.

B. Heavy metals

Trace element data in fish and shellfish, gained from a baseline study, from different investigations and national monitoring programmes provide some insight into geographical differences in the levels of the contaminants involved. (Baltic Marine Environment Protection Commission 1990) HELCOM concludes in its "Second Assessment" that it is still very difficult to compare data from different laboratories, owing to methodological uncertainties. Without such basic scientific studies it is not possible to assess the fate of pollution by trace metals entering and leaving Baltic waters, from their accumulation in recent sediments. (Voigt 1986) There is an urgent need for intercomparison and standardization. However, the decrease of copper, cadmium, zinc, and lead in fish since 1978 to levels comparable with the North Sea are showing the success of intergovernmental cooperation within HELCOM.

C. Organic pollutants

The prohibition of dichlorodiphenyltrichloroethane (DDT) use in all littoral States through the Convention resulted in a decrease of DDT concentration in seabird eggs and herrings. Consequently, the stock of fish-eating seabirds increased since 1970. Other harmful organic pollutants of great concern like PCB, PCT, HCH, etc. are more complicated to measure. New measuring methods prevent a direct comparison with older ascertained concentrations. Expensive high-tech methods and the need of very experienced analysts are still limiting success. This is a particular problem for regional cooperation in science, because new methods are difficult to introduce and standardize among the different countries in the Baltic region with such different socio-ecosystems. Another problem is the great variety of sources: riverain input, direct discharges, and airborne transport which need simultaneous international product-control regulations and national efforts to control emissions from all responsible sectors.

D. Plant nutrients

Seventy thousand tons of phosphorus and one million tons of nitrogen (as nitrate, ammonia and organic compounds) are discharged annually into the Baltic Sea. This fertilizing should have an impact on the algal growth. In fact, in the period between 1980-1985 in many parts of the Baltic Sea the nutrient concentrations increased, but at the same time, saline water from the bottom layer surged to the surface. Therefore, it is not easy to distinguish the origin of increased nutrient concentrations. However, strengthened investigation of the deep-water layers and measuring of nutrient input by river discharge must be strengthened.

E. Eutrophication

Increasing concentrations of phosphorus and nitrogen in the winter water often precludes an intensive phytoplankton springbloom. The later biodegradation of this biomass consumes oxygen, which is the reason for the increasing oxygen depletion in the bottom layer of the Baltic Sea. Scientific proof of this phenomenon has been given. (Babenerd and Meyerhöfer 1988) For the summertime the cooperating monitoring programme of HELCOM could measure an increase of primary production comparing the time-scales 1975-1978 and 1980-1983. The second Periodic Assessment of the State of the Marine Environment of the Baltic Sea describes a further increase of nutrient concentrations during 19841988, but in recent years the Commission could observe a stagnation in several areas of the Baltic Sea. However, the release of phosphorus from the sediment under anoxic conditions is still increasing. Another new phenomenon in the Baltic Sea is the appearance of toxic algal blooms like Gyrodinium aureolum and Prorocentrum minimum.

HELCOM: Organization and policy

Many articles have been written about the organization and policy of the "Helsinki Convention." Nobody denies that HELCOM is, in comparison with other intergovernmental agreements, very successful and a model in cooperation and efficiency. But insights into the reality of the Convention allow perhaps a better assessment of their problems and successes.

Obviously one of the secrets of a successful intergovernmental cooperation in science is a functioning communication system between the different States, their governments, and the scientists. In Germany, it is the Federal Minister of Transport who has the primary responsibility in the Cabinet for matters related to the Convention on the Protection of the Marine Environment of the Baltic Sea Area, including the "Helsinki Convention." The Deutsches Hydrographisches Institut (DHI), a Federal agency, has responsibility for monitoring the Baltic Sea, and to forward the information, for example, monitoring data. HELCOM contacts the Federal Ministry for Research and Technology or the DHI directly. These organs then forward the information to the responsible scientists (e.g., marine biologists at the "Institut für Meereskunde" in Kiel). A weakness in this information pathway is that the responsible scientists sometimes do not get the information in time in the complete form. A closer information network should be established between HELCOM and the scientists. The successful direct cooperation among scientists from different countries confirm this suggestion.

The recognition of the two German states was the political prerequisite for the "Helsinki Convention." But there are still political and socio-economic differences between the "western" and "eastern" world. The Convention had the delicate role of establishing scientific and technological cooperation within all seven littoral States of the Baltic Sea. Therefore, since the Convention has been in force in 1980, more than ten years of a remarkable cooperation must be appreciated. Difficulties in cooperation, however, have obviously existed in the past and remain to be solved. The official communication and basic data exchange between HELCOM and the USSR was sometimes very difficult. This situation was aggravated by the fact that many scientists of the USSR or Poland were unable to obtain travel permits. The communication between "western" and "eastern" scientists is based mostly on private efforts, and so such a lack of information resulted in great difficulties for the cooperation between the states and HELCOM.

The new and existing political development in all of the eastern countries has led to a completely new situation. But the opening of the "east" is also problematic. Poland, for instance, has financial problems for the running of scientific programmes, especially with regard to such expensive equipment as is used for the chemical part of the monitoring programme.

6. Comparison between HELCOM and regional seas institutional framework

The United Nations Environment Programme (UNEP) was established in 1972; it designated the oceans as one of its first priorities, and endorsed a regional approach to maritime environmental problems. As a result, the UNEP Regional Seas Programme was established in 1974 with an initial focus on the Mediterranean Sea. HELCOM served as a model for its establishment. For a comparison of HELCOM and the Regional Seas Programme, it is instructive to compare HELCOM and the "Mediterranean Action Plan," the first of the six programmes now in formal operation.

In a way, the history of both agreements has many parallels. Like the ICES for the Baltic region, the International Commission for Scientific Exploration of the Mediterranean Sea (Monaco) of 1910 was the basis for scientists to collect and exchange data on the causes and effects of marine pollution. (Boxer 1982)

Since the early 1970s several UN organizations have been acting on the basis of a growing awareness of problems of the Mediterranean Sea (FAO, IOC, UNESCO, IMO). In 1974 UNEP set up a comprehensive Action Plan for the Mediterranean Sea. The Plan was adopted in 1976 by 16 of the littoral States.

The four principles of the Mediterranean Action Plan are:

a. a legal framework for cooperation, in the form of an umbrella convention and a series of technical protocols;

b. a plan for coordinated scientific research, monitoring, and information exchange as a basis for determining priorities and policy;

c. provisions for institutional and financial arrangements; and

d. an integrated planning and development component, including socio-economic considerations. (Gebremedhin 1989)

Obviously, there are organizational and administrative differences between the Action Plan and HELCOM, but the research and monitoring component of the two agreements is comparable. However, the Mediterranean Action Plan goes a decisive step further. Within the framework of the Mediterranean Action Plan the "Blue Plan" was formulated and adopted in 1975 in Barcelona under the auspices of the United Nations Environment Programme. The Blue Plan recognizes the need for economic growth in the region, but with the constraint that such development must be environmentally sound. (Gebremedhin 1989)

The recognition of the importance of socio-economic development for a region where scientific cooperation should be established could be a model for the new political situation in the Baltic region. The dramatic changes in the former USSR and Poland and the reunification of the two German States intensify the need for a "Baltic Blue Plan."

The lesson from HELCOM for the regional seas institutional framework is on the organizational and administrative level. HELCOM as the executive component of the "Helsinki Convention" has the advantage of a relatively small and independent administrative organization. Although this administration is well defined there are still the above-mentioned problems of communication between HELCOM and the people from the participating countries who are involved. For a more effective coordination, communication and scientific cooperation must be conducted in a most direct way.

However, the Baltic region differs from the Mediterranean area in several important aspects which makes direct comparison very difficult. In the Baltic, tourism does not play as dominant a role as in the Mediterranean area. Tourism is, on one hand, a serious pollution problem, and on the other hand, a prospective financing source, if new financial concepts could be realized. Another difference is the rapidly growing population in the Mediterranean area whereas the population in the Baltic region is relatively stable.

Both Conventions provide a framework for cooperation where each can serve as a model for the other in some special way.

7. Further prospects

The Second Periodic Assessment of the State of the Marine Environment of the Baltic Sea, 1984-1988, gives in its general conclusions detailed information about requisite measures for the future. Conclusively there is still a need for greater knowledge about:

- the water exchange between the North Sea and the Baltic Sea,

- the reasons for the increased pH,

- the biological degradation of organic pollutants,

- the early stages of development of fishes, and

- the total volume input of organic pollutants.

These are just some points of the mentioned scientific needs.

Furthermore, the Second Periodic Assessment requires the continuation, and an extension of the Baltic Monitoring Programme (BMP). The efficiency of the BMP could be enhanced if the planning of surveillance cruises were better coordinated in a central point. This would improve data supply and use. At present, uncertainties in data handling is due above all to insufficient accessibility and lack of quality control by users.

The completely new situation and the continuous rapid political and socioeconomic development of the eastern countries of the Baltic region make it difficult to make projections for the future. What is certain, however, is that the need for scientific and technological support will increase. The exchange of data and experience between HELCOM and the eastern countries and between scientists and the various States may, in fact, become easier. As an important result of this development, the possibility to combat land-based pollution in the entire drainage basin of the Baltic Sea is increased.

The reunification of the two German States opens new possibilities for a reorganization of the Baltic research programme and a new division of labour in the new Germany. The Institut für Meereskunde in Warnemünde, in the former German Democratic Republic, for example, will be the prospective institute for Baltic oceanography. The Institut für Meereskunde in Kiel, on the other hand, could assume the full responsibility for global oceanographic research.

Summing up, recent political development raises hopes for improved intergovernmental cooperation in the Baltic region, including a development programme, with HELCOM providing financial and logistic support for the eastern countries of the region. The "Mediterranean Blue Plan" could serve as a model to support this.

This brief and fragmentary overview of international cooperation in the Baltic region shows that many problems still await solution. However, there is the hope that efforts will continue in the best tradition of international marine science cooperation, and the political and socio-economic development in the eastern part of the Baltic region will open new horizons of cooperation in science and technology, so that once more the Baltic region will play a leading role for the benefit of the ocean and the peoples living on its shores.


Babenerd, B., and T. Meyerhöfer. "Studie zum Fischsterben in der Kieler Förde im Oktober 1988." Forschungsvorhaben Wasser 102 (1988), no. 4: 234.

Baltic Marine Environment Protection Commission - Helsinki Commission. "Second Periodic Assessment of the State of the Marine Environment of the Baltic Sea, 1984-1988; General Conclusions." Baltic Sea Environment Proceedings, No. 35 A, 1990.

Boczek, B.A. "The Baltic region in its historical context." In: Westing, A.H., ed. Comprehensive security for the Baltic. PRIO, UNEP, SAGE publications: 1989, 23-34.

Boxer, B. (1982) "Mediterranean pollution: problem and response." Ocean Development & International Law 10 (1982): 315-356.

Broms, B. "Multilateral agreements in the Baltic region." In: Westing, A.H., ed. Comprehensive security for the Baltic. PRIO, UNEP, SAGE publications: 1989, 62-71.

Ehlers, P. Marine scientific cooperation in the framework of the Helsinki Commission. Kieler Meeresforschungen, Institut für Meereskunde an der Universität Kiel. Sonderheft No. 6; The Baltic Sea Environment, 1988.

Gebremedhin, N. "Lessons from the UNEP Regional Seas Programme." In: Westing, A.H., ed. Comprehensive security for the Baltic. PRIO, UNEP, SAGE publications: 1989, 90-98.

Jenisch, U. "Die Ostsee als Wirtschafts und Lebensraum. Wirtschaft, Umweltschutz, Seerecht." German Yearbook of International Law, vol 33, 1991, 349-382.

Kremling, K. "Dissolved trace metals in waters." In: First Periodic Assessment of the State of the Marine Environment of the Baltic Sea area, 1980-1985. Baltic Sea Environment Proceedings, 17B, 1987, 209-219.

O'Dell, A. Scandinavian World. London: Longmans, Green, 1957.

Voigt, K. "The Baltic Sea - pollution problems and natural environmental changes." In: Richardson, J.G., ed. Managing the Ocean: Resources, Research, Law. Mt Airy (USA): Lomond Publications, 1986, 159-167.

Zmudzinski, L. "Environmental quality in the Baltic region." In: Westing, A.H., ed. Comprehensive security for the Baltic. PRIO, UNEP, SAGE publications: 1989, 46-53.

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