Microplastic, an Emerging Threat to the Global Seagrass Ecosystems: A Review

ABSTRACT Seagrass, a type of marine plant that grows into meadows in intertidal zones and shallow coastal waters, can contribute to numerous ecological and economic benefits. Benefits include carbon sequestration, habitat for marine species, coastal protection, and raw materials for medicines and fertilizer production. However, seagrass faces global decline due to pressure from human activities and water pollution. In the marine environment, one of the emerging pollutants that has been increasingly studied is microplastic. Microplastics are plastic particles less than 5 mm in size that can be accidentally ingested by marine fauna and act as vectors to other contaminants such as heavy metals. Microplastic ingestion effects include physiological stress, disruption of food webs, and alteration of microbial communities, which impact nitrogen cycling and biodiversity. Microplastics in global seagrass ecosystems are primarily fibers and fragments, blue and black colored, and have polypropylene (PP) and polyethylene (PE) origins. This review, based on 18 global studies from diverse geographical regions including Europe, North America, Asia, and Oceania, highlights the current understanding of microplastic contamination in seagrass ecosystems worldwide. Further studies are needed to address the research gaps to assess the impacts of microplastics and develop effective conservation strategies for marine ecosystem preservation.