Baltic Earth Working Group on Marginal Seas – Humans and environment

• How does the Baltic Sea differ from other marginal seas, or which marginal seas are similar to the Baltic
  Sea?
• What are the regional peculiarities of the relationships between drivers in Earth systems with regard to
  marginal seas, and which of these relationships are invariant with respect to their regional assignment
  and indicate analogies?
• How can identifying analogies of drivers in marginal seas’ Earth systems help to optimize sustainable
  development concepts?

Marginal seas are highly sensitive regions of the world's oceans, equally exposed to the pressures of climate change and increasing anthropogenic impacts through the overexploitation of natural resources. These pressures lead to the progressive deterioration of fragile marine ecosystems and necessitate complex management strategies for their protection and the sustainable use of valuable marine resources. This requirement not only presents regional challenges—such as those faced by the Baltic region—but is increasingly taking on a global dimension. A significant challenge in this context is the persistent gap between society’s demand for effective management strategies and the scientific understanding of the cause–effect relationships linking environmental drivers to key, tunable ecosystem parameters in marginal seas. Bridging this gap requires not only solutions tailored to individual seas but also efforts to generalize across their diversity, thereby supporting the development of standardized and transferable concepts for sustainable management. For a generalized sustainable development of marginal seas in line with the UN Sustainable Development Goals (SDGs), a comparison with the Key Messages of the latest IOC Ocean Report 2024 is a useful tool when seeking analogies.
Historical datasets and accumulated scientific knowledge provide an important basis for comparing marginal seas worldwide and for developing a taxonomic framework that enables such generalisation. RT7 aims to contribute to this emerging taxonomy by examining the interplay of climatic, geological, ecological, and socioeconomic systems as drivers of environmental change. The spatial framework is set by the shelf seas, their coastal zones and drainage areas. The time frame is determined by the last glacial cycle, but especially the postglacial time – the period of human-nature interaction. Data sources to be considered range from local and regional monitoring programmes – including, where available, high-frequency or real-time observations – to global satellite-based observations. Long-term trends in human–nature relationships will be reconstructed using proxy data from natural archives interpreted through transfer functions. Numerical functional models and emerging machine-learning approaches provide powerful tools for evaluating and integrating these datasets.

Potential activities within RT7 include organising workshops, topical sessions at scientific conferences, and targeted publications to facilitate discussion of scientific results and to communicate findings to the broader public. To achieve its scientific objectives, the working group will collaborate closely with other Baltic Earth working groups and maintain active links with scientific organisations and institutions beyond the Baltic region. During the first phase, a joint publication (white paper) is planned as a review article outlining the current state of marginal seas research and future directions, with the aim of initiating a broad discussion on a general concept for the sustainable development of marginal seas (“upscaling of knowledge”). The working group also aims to collaborate with scientists from overseas to promote global comparative studies of marginal seas.

• 1st WG Meeting (online) 24.10.2024: minutes
• 2nd WG Meeting (online) 29.1.2025: minutes
• 3rd WG Meeting (hybrid) 28.5.2025: minutes
• 4th WG Meeting (online) 2.6.2026: minutes