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Wadden Sea Trilateral Cooperation

Case Authors

Jennifer Lee Johnson, Julia Wondolleck and Steven Yaffee, University of Michigan


The Wadden Sea Trilateral Cooperation is an effort by Denmark, Germany and the Netherlands to improve the ecosystem of the Wadden Sea, the largest continuous system of tidal sand and mud flats, salt marshes, and barrier islands. The Wadden Sea forms a transition zone between the coastline and the North Sea.

The cooperation began in 1978 through a high-level conference among ministers of the three nations, which share coastline along the Wadden Sea. The cooperation has no legal authority, but seeks to harmonize national management strategies and activities relating to the ecosystem.

A new governance structure was created in 2010 when the three nations updated the priorities of the effort to focus on climate change, invasive species, and the decline of bird populations and fisheries.

The effort provided valuable background information that was instrumental in the addition of the Wadden Sea to the UNESCO World Heritage List in 2009. It also has led to improved data collection and the sharing of information. It struggles to incorporate stakeholder input and balance development with conservation goals.


MEBM Attributes

  • Scale: Focus on an ecosystem scale across political boundaries.
  • Collaboration: Development of a multi-national consensus.
  • Adaptive Management: Commitment to adapt the structure of the initiative and reassess threats to the ecosystem.


Mission and Primary Objectives


The Trilateral Cooperation on the Wadden Sea involving Demark, Germany and the Netherlands stated its overarching goal is to achieve, as far as possible, a natural and sustainable ecosystem in which natural processes proceed in an undisturbed way.


A 1991 declaration defined the objectives as:

  • Maintaining the water movements and attendant geomorphological and pedological processes.
  • Improving the quality of water, sediment and air to levels that are not harmful for the ecosystem.
  • Safeguarding and optimizing the conditions for flora and fauna.
  • Maintaining the scenic qualities of the landscape.


Key Parties

Lead Organizations


  • Minister of the Environment


  • Minister for the Environment, Nature Conservation and Nuclear Safety

The Netherlands

  • Minister of Agriculture, Nature and Food Quality


  • Danish National Environmental Research Institute at Aarhus University


  • National Park Ministries
  • State Ministries for the Environment in Schleswig-Holstein, Hamburg and Lower Saxony

The Netherlands

  • Ministries of Agriculture, Nature and Food Quality
  • Ministries of Transport, Public Works and Water Management

Key Parties

International Non-Governmental Organizations

  • Seas at Risk
  • World Wildlife Fund for Nature


Program Structure

The Trilaterial Cooperation on the Wadden Sea, which involves the nations of Denmark, Germany, and the Netherlands, revised its operating framework and approved the following program structure, effective 2010:

  • Secretariat. A Secretariat based in Germany provides logistical support for the cooperation, supports scientific networks and projects, and handles communications and financial matters.
  • Trilateral Wadden Sea Governmental Council. Composed of high-level ministers from each nation, the council meets every three to four years. It establishes and oversees the cooperation, provide political leadership, assure the development of international policy, and harmonize decision-making among the three nations.
  • Wadden Sea Board. The board is the primary governing body of the cooperation. The board prepares, adopts and implements the Joint Declaration. It provides strategic and collective leadership, ensures internal performance and accountability, and maintains relationships with stakeholders. The board meets at least once every two years and is chaired by a senior government official appointed by the council. The position rotates among the nations. Each nation also appoints four people to the board.
  • Wadden Sea Forum. The forum is the primary mechanism to include stakeholder consultation. It includes more than 300 people from national and local governments, natural protection agencies, and interests representing the agriculture, energy, fisheries, harbor, industry, and tourism sectors. The forum is guided by a steering committee and six working groups. It functions as an independent organization and lacks a formal mechanism to incorporate its advice into the work of the multi-national cooperation.


Motivations for Initiating Effort

Public concern for water and air quality increased in the 1970s. Denmark, Germany and The Netherlands, which share the Wadden Sea, were motivated to harmonize existing international obligations as they related to the protection of the ecosystem.

In 1978, ministers from the three nations met in the Hague at the first Govern mental Conference on Protection of the Wadden Sea. The scientific and environmental communities in the nations wanted to establish common ecological targets for the region and harmonize the collection of ecological data.

In 1982, the three nations formalized their relationship with the signing of the Joint Declaration on the Protection of the Wadden Sea. It established a formal Trilateral Cooperation on the Protection of the Wadden Sea. The declaration solidified the intent of each nation to consult the others regularly to harmonize national activities and measures to protect flora and fauna of the Wadden Sea.

In 1985, the parties agreed to establish a Secretariat to “support, initiate, facilitate and coordinate” the activities of the cooperation. The Secretariat is based in Wilhemlshaven, Germany.

Initial efforts focused on water quality and wise-use of the resource through integrated coastal zone management. Efforts are now moving to integrate stakeholder involvement, sustainable development and establishing protected areas in both terrestrial and marine contexts.

Ecosystem Characteristics and Threats

The Ecosystem

The Wadden Sea ecosystem is the world’s largest continuous system of tidal sand and mud flats, salt marshes, and barrier islands. It forms a transition zone between the North Sea and the coasts of Denmark, Germany and the Netherlands. Six estuaries carry fresh water into the ecosystem.

The Wadden Sea contains exceptionally high biological productivity, species diversity and ecological specialization of birds, mammals, fish and bivalves. The ecosystem also sustains fish and crustacean populations well beyond its boundaries.

Among the rare coastal spawning birds found in the Wadden Sea are the Eurasian spoonbill, avocet, Kentish plover, and gull-billed tern. At least 52 populations of 41 migratory birds use the Wadden Sea as a stepping stone or wintering and molting habitat.

Marine mammals that spend all or portions of their lives in the Wadden Sea include pinnipeds and cetaceans, which serve as an indicator of the health of the ecosystem. Indigenous species include the harbor seal, gray seal, and harbor porpoise. Visiting species include the harp seal, hooded seal, ringed seal, bearded seal, and walrus. Cetaceans include the white-beaked dolphin and white-sided dolphin.

Important fish species include the marine juvenile herring, sprat, anchovy, hook nose, butterfish, and the threatened smelt, sea trout, and salmon.

Commercial fisheries focus on mussels, cockles and brown shrimp.


  • Toxic Pollution: Toxins such as mercury, cadmium and iron enter the ecosystem through industrial areas adjacent rivers in the watershed, contaminated sediment imported from the North Sea, and atmospheric deposition from the industrialized northwest and central European countries.
  • Oil Pollution: Oil spills and contamination from tankers and shippers in the area is an ongoing threat, particularly to sea birds.
  • Excess Nutrients: Nutrient infiltration from households and industrial sites was a major cause of eutrophication that led to anoxic sediments, harmful blooms of algae and declines in seagrass beds. The amount of phosphate entering the ecosystem has been curbed, but reducing nitrogen infiltration has been more difficult.
  • Climate Change: Rising seas threaten to flood the tidal flats and salt marshes, greatly altering the ecosystem. Climate related changes in the migratory patterns of species also will alter the ecosystem.
  • Destructive Fishing: Dredging for mussels and cockles has degraded essential fish habitat.
  • Invasive Species: Non-native species, such as the Pacific or Japanese oyster, threaten to displace native species, such as the cockle. Birds that feed on cockles cannot feed on Japanese oysters.

Major Strategies

The Trilateral Cooperation on the Wadden Sea, which involves the nations of Demark, Germany and the Netherlands, seeks to promote coordinated management, research and problem-solving related to the ecosystem at national levels.

Each nation incorporates management directives from the European Union and has used its own authorities and legal structures to manage the resource. The cooperation has no implementing authority, but acts as a mechanism for the nations to exchange information and identify ways that common management regimes would improve the functioning of the ecosystem.

Monitoring, Assessment and Evaluation

Monitoring of the ecosystem and the evaluation of the Wadden Sea Trilateral Cooperation are important to the success of the effort.


  • Trilateral Monitoring and Assessment Group: Data collection and monitoring of the Wadden Sea are harmonized among Denmark, Germany and the Netherlands. The group includes national representatives of agencies involved in monitoring and data management. It implements and coordinates a monitoring program for the Wadden Sea and meets regularly to assess the health of the ecosystem. The findings are published every three years. If problems are identified, the group establishes ad-hoc expert working groups to explore and assess the issues.


  • An external evaluation conducted in 2007 involved interviews with key stakeholders in the three nations. Evaluators concluded that the cooperation added value to national protection efforts and was successful in preserving the Wadden Sea. Major recommendations included refreshing the foundational agreement, refocusing the goals, and alterations to the governance structure. In 2010, the nations acted on many of the recommendations when they revised the effort’s structure and updated its goals.



Although the Trilateral Cooperation on the Wadden Sea of Denmark, Germany and the Netherlands does not have legal authority, the effort has enabled direct and indirect actions to conserve the ecosystem and use it sustainably. Water quality has improved. Populations of seals and birds have increased. New oil extraction efforts and hunting are banned. The effort also has facilitated the harmonization of data collection and management strategies, and provided political support for national and local management efforts.

Factors Facilitating Progress

The progress of the Trilateral Cooperation on the Protection of the Wadden Sea has been facilitated by the following factors:

  • Perception of a Common Crisis: Dead seals, birds, fish and polluted waterwaters provided visceral evidence of a common crisis that required action by the three nations.
  • Legal Obligations: Legal requirements to implement European Union Directives, as well as more formal international obligations to protect areas of the Wadden Sea, helped build political support for the cooperation.
  • Sustained Funding: Sustained funding from the three countries, which enjoy high per capita GDPs, was a major asset to the continued work of the cooperation. When political will to implement the cooperation’s recommendations began to wane, the existence of sustained funding allowed the cooperation to continue.
  • Dedicated Individuals: A dedicated group of individuals was engaged with the cooperation since its inception, provided consistent leadership, and had extensive knowledge of the ecosystem.



The Trilateral Cooperation on the Protection of the Wadden Sea has encountered the following challenges: 

  • Establishing Timely Goals: Although the three nations agreed on the need to restore the Wadden Sea to a natural condition, taking steps in that direction proved to be exceedingly difficult. By the time a management strategy had been created and implemented, the issue had changed.
  • Managing Negative Feedbacks: Reducing nutrient loading in the ecosystem to prevent eutrophication also reduced the amount of food for fish. Now, scientists are contemplating dumping phosphate into the Wadden Sea to provide more food for valuable fish species.
  • Incorporating Stakeholder Input: The Wadden Sea Forum generates stakeholder input, but incorporating that information into the tri-national process is difficult. Many participants in the forum question its effectiveness.

Lessons Learned

People involved with the Trilateral Cooperation on the Protection of the Wadden Sea have learned:

  • Establish a Legal Basis for Cooperation: Although the freedom to exchange ideas without a legally binding agreement likely helped garner initial political support for the cooperation, the lack of a firm legal basis for the effort hindered implementation of its recommendations.
  • Link Scientists and Politicians: Although political agreement often is more difficult to reach than scientific agreement on the causes and potential solutions to problems in the ecosystem, making progress requires solid coordination between scientific experts and politicians.
  • Include the Human Dimension at the Outset: Including experts and government authorities from a wide range of relevant areas is essential to ensure that ecosystem-based management is inclusive of the ecological and socio-economic dimensions of the system.
  • Include Local Communities at the Start: Involvement of local stakeholders came after decades of relatively high-level debates and decisions. Including local participation from the beginning builds trust, understanding and allows for more effective and practical management strategies.
  • Recognize the Process is Slow: A great deal of time, funding, and expertise is required to advance marine ecosystem-based management. Old imperatives, institutions, and concerns do not disappear but should be an integral part of ecosystem-based management.

Website Links

The Trilateral Cooperation on the Protection of the Wadden Sea: