Plastic pollution has emerged as a critical threat to marine ecosystems. Plastic debris enters the aquatic environment primarily through land-based sources, including rivers and coastal regions, but also from marine-based activities and atmospheric transport. Microplastics are subject to weathering processes, including photodegradation, oxidation, and mechanical fragmentation, resulting in further size reduction and changes in physical properties. These transformations impact microplastics’ ability to adsorb pollutants and their buoyancy, influencing their distribution within the water column. Additionally, the colonization of microplastics by microorganisms forms a biofilm, altering their physical and chemical characteristics. Microplastic poses significant risks to marine life. These tiny particles are readily ingested by many organisms, leading to harmful effects such as digestive issues, malnutrition, and mortality. Furthermore, microplastics act as vectors for persistent organic pollutants, bioaccumulating in the food chain and potentially impacting human health. Ocean currents contribute to the accumulation of plastic debris in gyres, forming vast areas of marine pollution. Additionally, plastic particles can sink to the seabed, affecting deep-sea ecosystems. The impacts of plastic pollution on marine biodiversity and ecosystem function are profound, necessitating urgent global action to reduce plastic production and consumption, improve waste management, and develop effective clean-up strategies. This study investigates the complex pathways and consequences of plastics in the ocean. Understanding the transformation of microplastics is essential for assessing their environmental impact and developing effective mitigation strategies. This research contributes to the growing body of knowledge on microplastic pollution, providing insights into the complex processes governing their fate in the ocean and informing future studies on their ecological consequences. Addressing this complex issue requires interdisciplinary research, international cooperation, and public awareness to mitigate the long-term consequences for marine life and human well-being.