In the context of climate change assessment, understanding the relationship between vulnerability, exposure, and risk is crucial, particularly when applied to aquatic ecosystems, which are highly sensitive to environmental changes. Aquatic ecosystems, encompassing freshwater systems such as rivers, lakes, and wetlands, as well as marine environments including estuaries, coral reefs, and open oceans, are intricately linked to climatic conditions. The health and sustainability of these systems depend on a delicate balance of physical, chemical, and biological factors, all of which can be disrupted by climate change. The concepts of vulnerability, exposure, and risk provide a framework to assess how climate change impacts these ecosystems and to identify strategies for adaptation and management. Vulnerability in aquatic ecosystems refers to the susceptibility of these systems to harm due to climate-related stressors. It is determined by intrinsic characteristics of the ecosystem, including its ecological structure, species composition, and adaptive capacity. For instance, coral reefs are particularly vulnerable because they are highly sensitive to changes in temperature, ocean acidification, and sea-level rise. Similarly, freshwater systems are vulnerable to shifts in precipitation patterns, droughts, and extreme weather events, which can alter water flow, temperature, and nutrient levels. Vulnerability is not uniform across all aquatic ecosystems; it varies based on biodiversity, ecosystem connectivity, and resilience. Ecosystems with high species diversity and functional redundancy may exhibit greater resilience, reducing vulnerability, whereas ecosystems already stressed by pollution, overfishing, or habitat degradation may exhibit heightened vulnerability. Exposure, on the other hand,