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Cumulative impact assessment for ecosystem-based marine spatial planning.


Claims for ocean space are growing while marine ecosystems suffer from centuries of insufficient care. Human pressures from runoff, atmospheric emissions, marine pollution, fishing, shipping, military operations and other activities wear on habitats and populations. Ecosystem-based marine spatial planning (MSP) has emerged worldwide as a strategic instrument for handling conflicting spatial claims among competing sectors and the environment. The twofold objective of both boosting the blue economy and protecting the environment is challenging in practice and marine planners need decision support. Cumulative Impact Assessment (CIA) was originally developed to provide an overview of the human imprint on the world's ocean ecosystems. We have now added a scenario component to the CIA model and used it within Swedish ecosystem-based MSP. This has allowed us to project environmental impacts for different planning alternatives throughout the planning process, strengthening the integration of environmental considerations into strategic decision-making. Every MSP decision may entail a local shift of environmental impact, causing positive or negative consequences for ecosystem components. The results from Swedish MSP in the North Sea and Baltic Sea illustrate that MSP certainly has the potential to lower net cumulative environmental impact, both locally and across sea basins, as long as environmental values are rated high and prevailing pressures derive from activities that are part of MSP. By synthesizing innumerous data into comprehensible decision support that informs marine planners of the likely environmental consequences of different options, CIA enables ecosystem-based MSP in practice.

Application in MSP:
Type of Issue:
Type of practice:
Stage of MSP cycle:
Coherence with other processes:
Key words:


  • How can cumulative impact assessments be integrated in the MSP process? 
  • How can CIA support an ecosystem-based approach in MSP?
  • How did Sweden apply CIA in its MSP process? 
  • What are the limitations of the CIA methodology in MSP? 


This study focuses on the cumulative impact assessment methodology implemented in the Swedish MSP process. 


The study aims to provide an example of how cumulative impact assessments can be integrated in the MSP process and how it can support an ecosystem-based approach. 


The study is based on the integration of cumulative impact assessments in the Swedish MSP process through the application of the Symphony tool. A scenario analysis of CIA was conducted, and the results were adjusted to test specific mitigation measures.


The study highlights the implementation of cumulative impact assessments in the MSP process. It shows how the establishment of CIA scenarios within the MSP process favours an ecosystem-based approach. The study also provides the analysis of the limitations of this methodology. 


The CIA methodology applied in the Swedish MSP process can also be used in the MSP processes in other marine regions. 

Responsible Entity: 

Swedish Agency for Marine and Water Management. 

Costs / Funding Source: 

ClimeMarine project funded by the Swedish Research Council Formas. 

Contact person: 

Swedish Agency for Marine and Water Management: