Incorporating ecosystem component interactions and indirect effects in cumulative impact assessment models

Area of Science:

• Marine ecology
• Ecosystem modeling
• Environmental impact assessment

Background:

• Anthropogenic pressures on coastal seas necessitate strategic management.
• Existing cumulative impact assessment (CIA) models can be improved by incorporating ecosystem dynamics.

Purpose of the Study:

• To demonstrate how ecosystem component interactions and indirect effects can enhance CIA models.
• To assess the extent to which these interactions alter cumulative impact estimations.

Main Methods:

• A simplified, extended regional Symphony CIA model was applied to a Swedish case study.
• Five pollution- and climate-driven pressures on cod, herring, and plankton were analyzed.
• A systematic literature review determined impact weight scores for model advancement.

Main Results:

• The refined CIA model showed an 117% increase in total cumulative impact in the study area.
• The updated model provided a more spatially detailed outcome with greater variability in impact magnitude.
• New, previously unhighlighted, areas under pressure were identified.

Conclusions:

• Integrating ecosystem interactions and indirect effects is crucial for improving CIA models.
• Enhanced CIA models offer greater predictive power and ecological relevance for ecosystem-based marine management.
• This approach is essential for a holistic understanding and management of marine ecosystems.