Denmark consists of the northern part of the Jutland peninsula and an archipelago of 406 islands bordering both the Baltic Sea and North Sea, and has substantial maritime influence. This prominence is attributed to its expansive coastline, which is the 17th longest in the world, alongside a sizeable Exclusive Economic Zone and role as an Arctic power.Flanders Marine Institute (2023). "Maritime Boundaries Geodatabase: Maritime Boundaries and Exclusive Economic Zones (200NM)", version 12. Denmark is also home to Mærsk, the world's second largest shipping company and Ørsted, an industry leader in offshore wind, and ranks as the fifth largest seafaring nation in the world[When?].

In June 2008, the EU adopted the Marine Strategy Framework Directive (MSFD) for marine environmental governance aiming to protect the marine environment across member states, ensuring the oceans are clean, healthy, and productively used. In May 2010, Denmark transposed the MSFD into legislation. After public consultation lasting until 27 August 2012, the first phase of Denmark's national marine strategy was approved. The Danish marine strategy delineates the MSFD's 11 ocean descriptors to realize good environmental status (GES), which include combating eutrophication. In compliance with the MSFD, Denmark must review and update their marine strategy every six years. In 2019, Denmark launched Marine Strategy II, which iterates on the initial plan with refined targets for the 2018-2024 period.Ministry of Environment and Food of Denmark (2019). Danish Marine Strategy II: Focus on a clean and healthy marine environment.

Following Denmark's Marine Strategy I and II's efforts to achieve GES, studies have found hypoxia in Denmark's coastal waters leading to marine life stress and habitat degradation. In September 2023, the total area affected by oxygen depletion was just below 7,500 km2 of which around a quarter was affected by severe hypoxia, the second highest mid-September oxygen depletion recorded in Danish waters since 1989.Hansen, Jens Würgler & David Rytter (2023). "Iltsvind i danske farvande 24. august – 21. september 2023". Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi. Rådgivningsnotat nr. (2023|44): 1-23. This revelation has resonated across media and political spheres, and the Minister of Environment, Magnus Heunicke, called the situation "alarming". The discovery of heightened hypoxia levels in Danish waters has emphasized the enduring complexities of implementing the Danish Marine Strategies effectively within Denmark's national boundaries and high seas.

Background In the early 1990s, Denmark positioned itself at the forefront of environmental policy by being the first country in the world to implement an energy action plan with carbon dioxide emissions targets. In this period, Denmark also stood out as one of the EU's most compliant countries in adhering to environmental legislation, often recognized as a 'green pioneer'.Burns, C., Gravey, V., Jordan, A. & Zito, A. (2019). "De-Europeanising or disengaging? EU environmental policy and Brexit". Environmental Politics 28(2): 271-292. Today, both the Prime Minister, Mette Frederiksen, and Minister for Development Cooperation and Global Climate Policy, Dan Jørgensen, highlights the country as a 'green pioneer'. Yet, Denmark's carbon footprint per capita is among the largest in the world and the country has historically struggled to comply with EU regulations on ocean protection.Minter et al. (2023). "Danmarks globale forbrugsudledninger", Tænketanken Concito, August 2023.

In 2013, the European Court of Justice found Denmark in breach of the Water Framework Directive. The violation was due to Denmark's delay in publishing and communicating its river basin management plan for 2009–2015. This was initially due on 22 December 2009, but completed on 30 October 2014.Miljøministeriet (2014). "Til Folketingets Europaudvalg og Folketingets Miljøudvalg om dom i EU-domstolens sag C-190/14, Europa Kommisionen mod Kongeriget Danmark, om manglende opfyldelse af forpligtelser efter vandrammedirektivet", 30 October 2014. Denmark's compliance with the EU's marine directives has been a recurring challenge. In 2019, the Danish authorities sought further extension from the European Commission to fulfill their commitments to marine environmental improvements. The deadlines under the WFD were successfully postponed from 2009 to 2015, then to 2021, with the latest target now set for 2027.

EU marine legislation and implementation

Denmark's ocean governance has historically been shaped by international conventions and organizations. In 1996, United Nations Convention on the Law of the Sea (UNCLOS) defined the Exclusive Economic Zone (EEZ), which grants the sovereign state Denmark exclusive rights over marine resources, including "the production of energy from the water, currents and winds" up to 200 nautical miles from its coast.United Nations (1982). "'Part V – Exclusive Economic Zone', in United Nations Convention on the Law of the Sea (UNCLOS).United Nations. (1996). Order no. 750 of 19 September 1996 concerning the delimitation of the continental shelf and the Exclusive Economic Zone of Denmark. Today, the EU significantly shapes Denmark's environmental strategy, influencing both the legislative framework and implementation of policies related to the marine ecosystem. This interconnectedness is reflected in the fact that 1/3 of Denmark's laws in the environmental, climate, energy and building sectors are derived from EU directives.

In 2000, the EU adopted the Water Framework Directive (WFD) which established a structure for protecting and monitoring the aquatic environment. The WFD requires member states to develop river basin management plans and programs of management to reach good chemical and ecological status and prevent deterioration.European Commission and Council (2000). Article 4. Directive 2000/60/EF of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. (Water Framework Directive). The WFD was transposed into Danish legislation in 2013 through the Water Planning Act, mandating the regular update of river basin management plans every six years to enhance the country's marine environment. In 2008, The Marine Strategy Framework Directive (MSFD) was launched by the EU as a complement to the WFD. The MSFD was designed to augment the existing legislation that aims to safeguard marine environment and does not replicate existing legislation such as the WFD or the Common Fisheries Policies (CFP) or undermine regulations by the International Maritime Organization (IMO). It is explicitly stated that "existing institutional structures established in marine regions or subregions, in particular Regional Sea Conventions, should be used to ensure such coordination", which include conventions such as HELCOM, BARCOM and OSPAR.European Parliament and Council (2008). Directive 2008/56/EC of 17 June 2008 establishing a framework for community action in the field of marine environmental policy (Marine Strategy Framework Directive). OJ L 164, 25 June 2008.

The MSFD sets 11 qualitative descriptors for determining GES, ranging from biodiversity to marine litter and human-induced eutrophication.European Parliament and Council (2008). Annex I. Directive 2008/56/EC of 17 June 2008 establishing a framework for community action in the field of marine environmental policy (Marine Strategy Framework Directive). OJ L 164, 25.06.2008. It requires member states like Denmark to develop marine strategies that include an initial assessment of the state of national marine waters, a definition of GES based on the descriptors, and the establishment of environmental targets.European Parliament and Council (2008). Annex IV. Directive 2008/56/EC of 17 June 2008 establishing a framework for community action in the field of marine environmental policy (Marine Strategy Framework Directive). OJ L 164, 25 June 2008. States must also put in place monitoring programs and take measures to maintain or achieve GES by the deadline. The MSFD is iterative, requiring cycles of assessments, revision and updates every six years to adapt to new environmental challenges and scientific insights. The MSFD incorporates a strong focus on public engagement and transparency in Article 19.European Parliament and Council (2008). Article 19. Directive 2008/56/EC of 17 June 2008 establishing a framework for community action in the field of marine environmental policy (Marine Strategy Framework Directive). OJ L 164, 25 June 2008. It mandates that member states, including Denmark, shall publish their marine strategies, progress reports, and results to ensure public scrutiny and comment. The requirement for openness and inclusivity ensures that the protecting and managing of marine environment is not just a governmental or scientific endeavor. It is one that involves and informs the wider community, acknowledging the societal importance of healthy marine ecosystems.

Danish Marine Strategy I (2012–2018) Denmark initiated its marine governance with the implementation of its inaugural Marine Strategy I (2012–2018) in 2010, which included the transposing of the EU's MSFD into Danish legislation.Miljøministeriet (2010). Lov om havstrategi. Lov nr. 522 af 26 May 2010. The Marine Strategy aligns with the EUs MSFD as it also delineates 11 ocean descriptors to attain Good Environmental Status (GES). As a part of the Marine Strategy I, a socioeconomic analysis was executed, assessing the value derived from utilizing the marine environment evaluated against the costs associated with potential environmental decline. The assessment identifies fishery and raw material extraction as primary threats to Denmark's seabeds, while pinpointing shipping, offshore wind, oil, and gas activities as the biggest sources to pollutants. These are also the biggest commercial Danish sectors. Of the threats and pollutant sources identified, only fishery is explicitly mentioned in the legislative text for regulation in the Marine Strategy Act. The Marine Strategy has a significant focus on the preservation of marine biodiversity and the protection of aquatic organisms, which are mentioned several times throughout the legislative text and in the central section on the purpose and scope of application for the law. However, in the Marine Strategy I and associated legislation, Denmark aims to only safeguard those aspects of the marine environment for which it is already responsible under existing directives.Rothenborg, M. (2012). "Naturen i havet: Miljøministeren gennemhuller havlov fra EU". Politiken, 23 September 2012, section 1, p. 6. The Danish Marine Strategy I garnered minimal media coverage, with only two articles appearing in major Danish newspapers in the period 2010–2013. Denmark never evaluated the environmental objectives' effectiveness from the Marine Strategy I.Greenpeace (2019). "Høringssvar til Danmarks Havstrategi II – Første Del". However, the country did update the strategy in 2019, resulting in the unveiling of the Marine Strategy II.Miljøstyrelsen (2019). Danmarks Havstrategi II

Danish Marine Strategy II (2018–2024) The Danish Marine Strategy II, spanning 2018–2024, builds on the initial strategy, incorporating an ecosystem approach to balance marine exploitation with environmental protection. The Strategy II upholds the 11 essential marine descriptors from Marine Strategy I and the MSFD to achieve GES. It includes an initial assessment of current marine conditions and sets 68 legally binding targets for improvement. The document details specific conditions and pressures within Danish marine areas, while highlighting the need for more knowledge and better monitoring methods to accurately assess environmental status and guide effective measures.