An Overview of Microplastic Pollution: Origins, Movement, and Effects in Marine Ecosystems

Over an extended period, the ocean has been utilised as a convenient sink for the disposal of various waste materials, including plastics. The presence and accumulation of plastics and microplastics in marine environments, including both open seas and coastal systems, are primarily driven by increased population growth and human activities. Once it has been dumped in the environment, plastic debris disperses in the sediment throughout the water column and has been documented in marine organisms via ingestion and entanglement. Microplastic debris is frequently ingested by marine organisms, including seabirds, whales, fish, and turtles, which often results in starvation due to gastrointestinal blockage. Moreover, floating plastics serve as vectors for the dispersal of invasive marine species, posing significant threats to marine biodiversity and the stability of the aquatic food web. The ingestion of microplastics also leads to the transfer of toxic pollutants such as heavy metals and Polycyclic aromatic hydrocarbons (PAHs) from the environment into the food chain and eventually into the human bodies which accumulate those toxins. This research compiles the most recent studies on microplastic (MP) pollution in the global marine environment and is further strengthened by a bibliometric analysis of Scopus-indexed publications over the past five years. The analysis highlights the rapid growth and increasing visibility of this field, thereby providing empirical depth to the review. Three key sections are emphasized: (1) sources, distributions, and major pathways of MPs in the marine environment, (2) interactions of MPs with heavy metals and PAHs contamination, and (3) the impacts of MPs and associated contaminants on marine ecosystems as well as Small Island Developing States (SIDS). Additionally, the global strategies for mitigating this issue have been outlined, with an emphasis on the roles played by various stakeholders. This includes the involvement of industries, government, non-government organisations (NGOs), stakeholders and consumers. The input in this study will serve as a foundation for future marine management and promote greater awareness of the impact of MPs on the marine environment.