Opinion Securing the Baltic Sea’s built seascapes

THE BALTIC SEA is transforming. Once defined by natural marine ecosystems and traditional maritime activities, it is now evolving into a built seascape, a marine environment increasingly shaped by human infrastructure. Offshore wind farms, subsea cables and digital monitoring systems are expanding rapidly, driven by the need for renewable energy, improved digital connectivity and enhanced security (Paolo et al. 2024). These changes bring significant opportunities and present complex challenges that demand new governance, co-operation and security approaches.

A paradox lies at the heart of this transformation; while offshore infrastructure is essential for economic growth and sustainability, it is also highly vulnerable. Recent incidents of sabotage, cyberattacks and political tensions have highlighted the risks of critical offshore systems. Additionally, the technologies shaping these built seascapes often serve a defence and civilian purpose. The question is how to balance innovation, security and environmental protection while ensuring that governance keeps pace with rapid technological advancements.

Human activity in marine environments has always been a source of promise—as well as risk, but today’s built seascapes represent a fundamental shift. Temporary interactions such as fishing and shipping can impact aquatic ecosystems and even disturb the seabed. Still, offshore wind farms and subsea infrastructure represent human presence at sea by adding (semi-)permanent constructions to the marine environment. This requires a different form of long-term planning, maintenance and protection. In the EU, this transformation is particularly evident as countries invest in offshore energy production to strengthen energy security and meet climate goals, which aligns with RePower EU, the EU’s plan to end its reliance on fossil fuels. However, this growing reliance on offshore systems also introduces new risks.

One of the most pressing concerns is the vulnerability of critical infrastructure. The damage to subsea gas pipelines and communication cables in recent years has exposed the fragility of these networks. The Baltic Sea, surrounded by multiple countries (some with competing interests) is a region where infrastructure security is increasingly under scrutiny. Offshore wind farms could contribute to clean energy production, but they also raise concerns about data security, navigation safety and international tensions. Addressing these risks requires approaches that integrate security measures without hindering innovation.

Data and technology are at the core of ensuring resilient seascapes. Offshore wind farms, subsea cables and digital sensors generate vast amounts of data, which can be used for energy management, environmental monitoring and maritime safety. For instance, real-time ocean monitoring can optimise shipping routes, track climate change impacts and detect potential security threats. However,
the benefits of this data depend on how effectively they are shared and managed.

Much of the data collected from offshore infrastructure remain siloed within specific industries or state agencies. While energy companies monitor turbine performance and subsea cables, defence agencies track underwater movements, and environmental researchers study marine biodiversity, these datasets are rarely integrated. A more collaborative approach in which stakeholders share critical insights, while maintaining necessary security restrictions, could enhance economic efficiency and regional security.

However, this integration is not without challenges. Many technologies used in built seascapes have dual-use capabilities, meaning they can serve both civilian and military purposes (Vaynman & Volpe, 2023). For example, surveillance systems designed for offshore energy operations could also be used to track naval activity, raising concerns about data access and national security. Finding the right balance between open data exchange and necessary restrictions will be crucial for future governance.

Governance is at the center of the built-seascape debate. As a semi-enclosed space where there are multiple foreign-policy interests to consider, the Baltic Sea presents unique governance challenges. International agreements such as the United Nations Convention on the Law of the Sea provide a legal framework, but they do not fully address the complexities of offshore digital infrastructure, cybersecurity and the integration of civilian and defence technologies.

A key challenge is ensuring that governance keeps pace with technological change, particularly as the expansion of offshore infrastructure brings both opportunity and risk. For instance, the rise of wind farms in the Baltic Sea presents an energy-security advantage. However, their integration with subsea communication cables and surveillance networks raises concerns about cybersecurity threats and international conflict (Bueger & Liebetrau, 2021). Similarly, the dual-use nature of maritime technologies, such as autonomous underwater drones used for both environmental monitoring and naval reconnaissance, complicates regulatory oversight (Vaynman & Volpe, 2023).

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Policymakers, industry leaders and academics must work together to develop regulations that encourage innovation while safeguarding critical infrastructure. Regional co-operation among Baltic Sea states will be essential to address these challenges, as demonstrated by Sweden and Finland’s long-standing collaboration on icebreaker operations and digital navigation safety (Boström & Österman, 2017). Additionally, Nato’s increasing focus on hybrid threats in the region underscores the need for standardised security protocols and co-ordinated response strategies (Liebetrau & Bueger, 2024). By establishing shared frameworks for data governance, risk mitigation and cross-sectoral collaboration, states can enhance both economic resilience and national security in this rapidly evolving seascape.

Public-private partnerships can also play a crucial role in strengthening the resilience of built seascapes. Energy companies, maritime industries and research institutions are already investing in advanced monitoring systems and AI-driven analytics to enhance infrastructure security.

For example, offshore wind operators have tested the integration of surveillance sensors into wind turbine networks, allowing them to detect vessel movements and underwater disturbances, thereby contributing to both energy security and maritime situational awareness (OX2 2024). Similarly, Nato’s Maritime Command has explored collaborating with civilian outfits to improve subsea infrastructure monitoring, leveraging data from commercial sensor networks and AI-driven threat-detection tools (Willet, 2025). The use of federated data-sharing models that make it possible to selectively access environmental and security data without compromising sensitive information, represents another promising area of co-operation (Trice et al., 2021). By working together, these stakeholders can create more resilient systems that benefit economic development and environmental sustainability, ensuring that offshore infrastructure remains secure and operational in an increasingly complex political landscape.

Mistra Co-Creating Better Blue (C2B2) (Wehn et al., 2023) is a Swedish research programme that experiments with living labs to let stakeholders find effective governance solutions in the increasingly crowded and contested marine space. The participants in the C2B2 LivingLab for Baltic Proper especially have to deal with rapidly evolving security realities.

The transformation of the Baltic Sea into a built seascape presents significant opportunities and new risks. Offshore energy production, digital connectivity and advanced monitoring systems are essential for economic growth and sustainability, but they also introduce security vulnerabilities that cannot be ignored. Effective governance, enhanced co-operation and strategic use of data will be key to ensuring that these built environments remain resilient and sustainable. Moving forward, policymakers, industries and academics must adopt a more integrated approach to managing built seascapes.

By strengthening cross-sectoral collaboration and improving data governance, we can navigate the challenges of this new maritime era—ensuring that the Baltic Sea remains a secure, thriving and sustainable maritime space for generations to come. Looking at past and present examples of multi-sector and civilian-military collaboration could help navigate the current international-affairs landscape.

Karina Barquet is the head of the Mistra Co-Creating Better Blue (C2B2) LivingLab East programme.

Hans Liwång is a professor at the Swedish Defence University.

Torsten Linders is a project co-ordinator with the University of Gothenburg.

Their research was financed by Mistra C2B.

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