Life Cycle Assessment as a Tool for Improving the Marine Environment in Construction Projects

The expansion of coastal areas for infrastructure and other human activities places increasing pressure on the ecological condition of the marine environment. The destruction of natural habitats has a documented negative impact on marine ecosystems, and the establishment of hard habitats is therefore essential to mitigate damage and support ecological restoration.
Concrete is a key material in marine construction, but its production and use contribute significantly to environmental impact. At the same time, literature reports a lack of interdisciplinary communication between engineering and biological disciplines, which restricts the development of more sustainable solutions.
Life Cycle Assessment (LCA) is a crucial tool for quantifying and optimizing the environmental impact of marine structures. LCA should not only be used for post-project evaluation but should be integrated early in the design phase to guide material selection and design decisions towards reduced environmental mpact. The LCA modeling of the Køge Bay reef structure “Circle Reef” demonstrates how changes in cement type and concrete design can reduce environmental burdens. Furthermore, the analysis highlights the importance of including multiple impact categories, as improvements in one category (e.g., carbon footprint) may lead to trade-offs in another (e.g., marine ecotoxicity).
This emphasizes the need for a holistic approach, where LCA is used as a strategic tool to promote sustainability in marine projects—not merely as documentation, but as an active foundation for decision-making in design and implementation.