Increases in global population and seafood demand are occurring simultaneously with fisheries decline in an era of rapid climate change. Aquaculture is well positioned to help meet the world’s future seafood needs, but heavy reliance of most global aquaculture systems on the ambient environment and ecosystem services suggests an inherent vulnerability to climate change. In order to design and implement a comprehensive and effective response, policy makers and farmers must have an informed understanding of how climate change will affect aquaculture sectors and reliant communities. Climate change vulnerability assessments are an internationally recognized assessment process that can aid the advanced planning of adaptation measures by identifying which sectors, regions, and species are the most threatened.
V ulnerability assessments are generally based on three components: ‘exposure’, ‘adaptive capacity’, and ‘sensitivity’. Vulnerability assessments can be challenging for several reasons. Firstly, data inputs are often combinations of quantitative and qualitative data, and the resultant model is typically described as semi-quantitative. Some quantitative inputs such as wind and wave exposure may have magnitude and frequency data generated from climatic models. Other inputs, such as farmers’ perception of risk, are equally crucial, but are subjective and qualitative. This means that a vulnerability assessment must stitch together very different types of information and translate these into a single understandable value. Another challenge is differences in data availability or scale. For example, high resolution storm surge models, capable of projecting flooding risk under different emissions scenarios, may be available for some coastal regions but not others. In this case, investigators cannot simply exclude storm surge risk, so instead they must pursue a more qualitative approach such as relying on expert opinion. This raises a third challenge: the difficulty of comparing vulnerability across regions that have been assessed using different data and vulnerability methods.
Notwithstanding these limitations, cli mate change vulnerability assessments are an important tool for guiding decision making . The increasing rate of climate-driven changes does not provide the luxury of waiting until all uncertainties and methodologies have been sorted . Here w e present current practices and limitations of climate change vulnerability assessments in aquaculture and suggest possible solutions to practically address these challenges and uncertainties.