Ecosystems provide services and benefits to humans, yet these services are rarely valued in environmental decision-making. Transitional waters at the interface of fresh and salt water are particularly valuable areas, which provide many services and face a high risk of degradation from multiple pressures. This study focused on ecosystem services of the Nemunas River Delta in Lithuania. Linking services to decisions requires a systems approach that captures the complex connections among system elements. We conducted a meta-analysis of existing studies to: 1) describe the services provided by the Nemunas Delta region; 2) develop a conceptual model to capture the interactions among human decisions, the pressures they create, and ecosystem services, using the DPSIR (Drivers-Pressures-State-Impact-Response) framework; and 3) identify tradeoffs among services for consideration in management.

Results/Conclusions

Primary ecosystem services for the Nemunas River Delta region are tourism, of which 70% is fishing, and biodiversity, serving as one of the key nesting sites of rare and vulnerable bird species. Additional services provided by this region are carbon storage, flood/storm protection, waste dilution, food and fuel, waterways, and recreation. A dominant pressure is nutrient loading, leading to algae blooms and impaired services. We identified four trade-offs between services: 1) Overuse of the resource by visitors can damage habitats and biodiversity; 2) consumption of fish by birds may reduce availability for anglers, and vice versa; 3) noise and visual pollution from oil drilling reduces aesthetic benefit; and 4) maintenance of waterways and pollution from boats can impair fish habitat. The analysis also highlight two areas where services responded similarly to pressures and may be bundled, or considered together: 1) healthy productive wetlands provide carbon storage, flood protection, and waste dilution; and 2) small-scale agriculture maintains open habitat for birds. This work contributes to the understanding of ecosystem services in transitional waters, where few studies have been conducted, and provides an organizing framework for integrated ecological research and environmental decisions.