Topics and trends in marine ecosystem services research over the long term

Abstract

Marine ecosystems cover approximately 97\% of the world's aquatic environments and are key providers of ecosystem services (ES), playing a critical role in regulating the global climate and supporting economies and societies. Despite extensive research on marine ES, previous studies have mainly relied on traditional narrative review approaches, which often lack comprehensive thematic synthesis. This study employs Latent Dirichlet Allocation topic modeling to analyze 9048 publications from the Web of Science (1990-2024) and identify key themes in marine ES scientific research. Primary topics in marine ES research emerged: Coastal protection, Marine policy, Coral reef recreational activities, Marine wildlife tourism, Coastal tourism and recreational fisheries, Climate change impact, Blue carbon systems' carbon storage, Microbial biotic materials and biofuels, and Water purification. Results indicate a growing interest in marine ES research, with all topics presenting significant increases in the absolute annual publication trends over time. However, trends in the topic proportion revealed that, year by year, Marine policy, Climate change impact, Blue carbon systems' carbon storage, and Microbial biotic materials and biofuels topics increased, while Coral reefs recreational activities, Coastal tourism and recreational fisheries and Water purification decreased year by year. These results were validated by comparing them with case studies spanning microorganisms to the macrofauna. The applied approach emphasizes the need for integrative methodologies to refine ES assessments, bridging the ecological, economic, and policy dimensions. This study provides a framework for future research, facilitating holistic insights into marine ES trends and their implications for global sustainability.