Environmental risks are intensified by the growing interaction between human-induced pressures and climate change (CC), leading to biodiversity loss and ecosystem changes that threaten the resilience and health of marine and coastal ecosystems, along with their ability to provide services. The increasing risks posed by CC require appropriate adaptation actions that can boost biodiversity while also benefiting people. In this setting, nature-based solutions (NBSs) play a crucial role in coping with climate impacts by improving ecosystem resilience, thereby protecting and restoring natural ecosystems while providing benefits for human wellbeing. Current literature mainly focuses on NBSs in terrestrial environments, while knowledge on their implementation (and effectiveness) in marine and coastal environments remains limited. In particular, the analysis of suitable conditions for their successful implementation is lacking in marine and coastal areas when environmental, socio-economic, and governance aspects are considered, and the concept of ‘suitability’ itself is characterized by the absence of a consolidated and widely recognized definition. Through a systematic approach, this review work aims to reduce uncertainty surrounding the concept of suitability by providing clear guidance for its consistent interpretation and application in real-world NBS design and implementation. To this aim, we assess the state-of-the-art scientific literature on methodologies, modeling tools, analytical frameworks, and approaches used to evaluate NBS suitability in marine and coastal ecosystems. Based on a pool of 26 papers covering the 2011–2025 timeframe, a period selected to align with the emergence and formalization of the NBS concept, the review confirms that a unique and shared definition of suitability is missing. Within the framework of this work, the concept has, therefore, been extrapolated from a selection of key papers drawn from the literature. Furthermore, the review results reveal that environmental indicators (e.g., slope, depth, and sea surface temperature) are most commonly used to analyze suitability, followed by socio-economic indicators (e.g., land use and distance from the coast, which act as proxies for human activities or infrastructure). However, the socio-economic and governance dimensions remain poorly explored in the analyzed publications; instead, methodological approaches mainly focused on environmental aspects that define the optimal physical, ecological, and chemical conditions for NBS implementation. Overall, the literature suggests that suitability models represent an essential decision-making tool for guiding nature-based adaptation in marine and coastal areas as they are fundamental to ensuring the success of implemented NBSs and the restoration and preservation of ecosystems.
Allegri et al. (Fri,) studied this question.