Where rivers meet the sea, the water isn’t exactly salty as it is in the sea. Neither is it fresh as in rivers. These “transitional waters” (TW), such as lagoons and river mouths (estuaries), are rich in wildlife and essential for fisheries, bird habitats, and local livelihoods. At the same time, they are highly vulnerable to pollution, urban pressure, and climate change.
To monitor, protect, and preserve TWs’ unique role in local ecosystems, a team of researchers from Klaipeda University, Latvia University, and the University of Algarve proposed a new sustainability framework called Emerald Growth. Their recent study not only describes this framework and its significance in connection to land-based “Green Growth” and ocean-focused “Blue Growth” but also tests the potential of this framework on a real-world example: Lake Liepāja, a coastal lagoon connected to the Baltic Sea.
What is Emerald Growth?
Emerald Growth is a way of managing coastal environments that recognises a simple truth: land, rivers, and seas are all connected. While traditional policies often separate Green Growth from Blue Growth, Emerald Growth brings these ideas together into one shared approach.
It promotes:
• Healthy ecosystems across the entire river-to-sea system (including TW)
• Strong and resilient local communities and economies
• Long-term cooperation between regions and countries that share TWs and coastal areas
• Decision-making based on ecological balance, not short-term gain
In short, Emerald Growth asks how people and nature can thrive together in coastal transition zones.
How can we measure sustainability?
As a theoretical foundation for aligning sustainability principles under the umbrella of Emerald Growth, the study uses the Coastal Circles of Sustainability (CCS) methodology. It allows for consistent and well-defined evaluation of coastal regions from multiple perspectives:
• Environment and ecology (water quality, biodiversity, nutrient cycles, land use)
• Economy (income, jobs, industry, and reliance on natural resources)
• Society and culture (demographics, housing, traditions, and wellbeing)
• Governance (policies, management capacity, public participation)
By evaluating these areas and bringing the insights together, a well-rounded view emerges. It is a valuable foundation for understanding what the biggest challenges are and shaping a united, future-orientated approach.
In combination, the two concepts shape a solid, well-rounded approach: Emerald Growth provides the vision, and CCS acts as the roadmap.
Lessons from Lake Liepāja
In this study, the researchers tested this combined approach in Lake Liepāja. A mix of environmental data, community workshops, and stakeholder interviews revealed an imbalance in the region. While some economic and governance conditions are relatively strong, serious social and economic pressures (low wages, expensive housing, declining population) are significant obstacles for sustainable progress. Researchers also emphasised the lasting effect of environmental damage and pollution left from the Soviet period.
To improve the situation, local experts and residents noted restoring parts of drained wetlands, removing polluted bottom sediments, and strengthening cross-border cooperation to better manage shared waters as key priorities.
With that said, the study also emphasises that there is no single solution for every coastal zone. Each location has its own environmental history, social realities, and governance challenges, raising the challenge of tailoring effective solutions on a case-by-case basis.
