Analysis of the ocean and marine health performances of 18 countries in the G20 countries: An application using the CEBM-based TOPSIS method

This study investigates the critical role of G20 nations in maintaining ocean health, given the significant influence their economic activities have on global maritime ecosystems. Employing the most recent Ocean Health Index (OHI) data (2023) and the CEBM-TOPSIS Multi-Criteria Decision Making (MCDM) method, the research assesses the ocean health performance of 18 countries G20 countries. The CEBM analysis identifies biodiversity, carbon sequestration capacity, fisheries sustainability, water quality, and coastal protection as the most important OHI criteria, respectively. According to the CEBM-TOPSIS method, Russia, Brazil, and France are the top three countries with the highest ocean health performance, while China, India, and South Africa are ranked lowest among the first three countries. Notably, the average performance score indicates that Russia, Brazil, France, the United Kingdom, Australia, Mexico, South Korea, the United States, Germany, Saudi Arabia, and Canada all exceed the average. This suggests a need for improvement among G20 countries with below-average performance to ensure a more substantial contribution to the global economy and interconnected dimensions. Finally, sensitivity, comparison, and simulation analysis validate the CEBM-TOPSIS MCDM method as a reliable tool for evaluating national ocean health performance.