Micro Plastics in The Marine Environment: A Review of Their Effects on Marine Organisms and Ecosystems

Abstract: Micro plastics, which are plastic particles smaller than 5 m, they are widely recognized as contaminants in marine environments, pose great threats to marine life and ecosystems, and have gathered much information in scientific literature. Examples of these particles are breakdown products of large plastics, synthetic materials, and even personal hygiene products. Marine organisms consume microplastics directly or indirectly from plankton to large crustaceans and mammals, leading to physical issues, chemical contamination, and altered eating habits. Consuming microplastics may cause internal harm, change digestion processes, and introduce toxins into the food chain. Additionally, microplastics serve as carriers for harmful chemicals, including persistent organic pollutants, thus highlighting the effects of these chemicals on marine organisms. Long-term exposure to micro plastic particles is linked with altered reproductive success, reduced growth rates, and loss of biodiversity in marine ecosystems. The ingestion of microplastics by marine organisms has been extensively reported across multiple trophic levels, including zooplankton, bivalves, crustaceans, fish, seabirds, and marine mammals. Research indicates that many species mistake microplastics for food due to their size, color, and movement, leading to unintentional consumption. For instance, copepods and other zooplankton have been observed ingesting microplastics suspended in the water column, which negatively impacts their feeding efficiency and energy intake. In bivalves like mussels and oysters, both laboratory and field studies have documented the accumulation of microplastics in digestive tissues, resulting in inflammation, reduced filtration capacity, and weakened immune function. The diverse distribution of micro plastic particles is not only a threat to marine biodiversity but also raises questions about the sustainability of marine resources. Addressing the effects of micro plastics on marine life requires comprehensive global efforts, including policy regulation, pollution reduction, and enhanced waste management practices. Standardized methodologies for sampling, detection, and toxicity assessment are urgently needed to enable consistent comparisons across studies and geographic regions. Enhancing microplastic detection techniques and developing reliable biomonitoring tools are crucial steps toward accurately measuring exposure levels and evaluating associated risks. Additionally, future research should prioritize the development and assessment of mitigation strategies, such as biodegradable material alternatives, more efficient waste management systems, and effective policy measures aimed at reducing plastic pollution at its source. This review explores recent research on the biological and ecological impacts of microplastic pollution on marine organisms. The ingestion of microplastics can cause physical harm, including digestive blockages, reduced nutrient uptake, stunted growth, and reproductive disturbances. Furthermore, microplastics serve as carriers for toxic chemicals and pathogens, leading to bioaccumulation and disrupting marine food webs. Particularly at risk are filter feeders, benthic species, and coral reef communities. Although awareness of these issues is increasing, significant gaps remain in understanding the long-term and population-level consequences of micro plastic exposure. It also provides a basic view on the types and effects of micro plastics on specific species and other health concerns.