Global research trends on bivalve biomarkers for heavy metal pollution: A bibliometric analysis

This study presents a bibliometric analysis of global research trends on heavy metal biomarkers in bivalves published between 2000 and 2025. The analysis was conducted using data retrieved from the Scopus database, resulting in 311 initial records, of which 309 documents met the inclusion criteria after screening. Bibliometric mapping and descriptive analyses were performed using VOSviewer and Microsoft Excel to evaluate publication trends, country contributions, leading authors, and keyword co- occurrence networks. The results indicate a substantial increase in publications after 2010, with a peak in 2020 (22 articles). France (52 publications), China (44 publications), and Italy (29 publications) emerged as the leading contributors, while tropical countries accounted for only 25 studies (approximately 8%), with Indonesia contributing a single publication. Keyword analysis identified four major thematic clusters: environmental monitoring and bioaccumulation, pollutant-specific chemical analyses, biochemical and molecular responses, and additional coastal contaminants such as polycyclic aromatic hydrocarbons (PAHs). These findings confirm the central role of bivalves as effective bioindicators of heavy metal pollution and highlight a persistent research gap in tropical regions. This study provides a focused bibliometric synthesis that can support future international collaboration, capacity building in tropical countries, and the integration of advanced approaches in marine biomonitoring.