The importance of coastal and marine ecosystems has been extensively explored due to their capacity to supply ecosystem services and thus contribute to human wellbeing. Nevertheless, these are some of the most anthropogenically impacted ecosystems globally. It is necessary to fully account for the contribution of nature and integrate this information into countries’ socio-economic dynamics. The System of Environmental-Economic Accounting—Ecosystem Accounting (SEEA-EA) was adopted by the United Nations in 2021 as a statistical standard to integrate the contribution of ecosystems and their services into the national accounts system. Since its adoption, the SEEA-EA has been increasingly implemented worldwide. However, its application in the coastal and marine environment is still limited. This is especially true when assessing ecosystem condition. As a relatively new topic within the SEEA-EA, there are many uncertainties within the community on how to assess marine ecosystem condition. The lack of standard guidelines makes it more difficult. This opinion article explored the three main challenges that hinder the operationalisation of assessing ecosystem condition. Specifically, the challenges of defining meaningful ecosystem condition variables in terms of representativeness and data availability. Then, the article explored the difficulties in rescaling condition variables into indicators by correctly defining appropriate reference conditions. Finally, it examined the challenges of calculating the condition index unbiasedly using indicator weights. Overall, there are still many critical challenges that need to be addressed. For this, it is essential to define clear guidelines and best practices for the community to accurately and meaningfully assess the condition of coastal and marine ecosystems.




