This review discusses the monitoring of plastic debris in marine environments, emphasizing the need for diverse and standardized approaches to assess the abundance, distribution, and impacts of plastic pollution. Plastic debris has significant environmental and economic impacts, and monitoring is essential to evaluate the effectiveness of mitigation measures. However, monitoring is complicated by spatial and temporal variability in plastic distribution and limited understanding of plastic pathways and long-term fate. Current monitoring methods include beach surveys, at-sea sampling, and monitoring the impacts on wildlife, such as seabirds that ingest plastic. Beach surveys provide insights into debris trends but are biased by cleanup efforts and beach dynamics. At-sea sampling requires large sample sizes due to high spatial and temporal variability. Monitoring impacts on wildlife, such as entanglement and ingestion, offers a cost-effective way to assess plastic abundance and composition. Monitoring waste disposal on ships and plastic levels in rivers and storm-water runoff helps identify major sources of plastic pollution. Different monitoring approaches are needed to answer different questions, but efforts should be made to standardize methods internationally. The review highlights the importance of standardized protocols, appropriate sampling designs, and the need for long-term monitoring to detect changes in plastic abundance and composition. It also emphasizes the role of seabirds in monitoring small plastic debris and the importance of assessing both the quantity and type of plastic entering the marine environment. Overall, the review underscores the complexity of plastic pollution and the need for a multifaceted approach to monitoring and mitigation.This review discusses the monitoring of plastic debris in marine environments, emphasizing the need for diverse and standardized approaches to assess the abundance, distribution, and impacts of plastic pollution. Plastic debris has significant environmental and economic impacts, and monitoring is essential to evaluate the effectiveness of mitigation measures. However, monitoring is complicated by spatial and temporal variability in plastic distribution and limited understanding of plastic pathways and long-term fate. Current monitoring methods include beach surveys, at-sea sampling, and monitoring the impacts on wildlife, such as seabirds that ingest plastic. Beach surveys provide insights into debris trends but are biased by cleanup efforts and beach dynamics. At-sea sampling requires large sample sizes due to high spatial and temporal variability. Monitoring impacts on wildlife, such as entanglement and ingestion, offers a cost-effective way to assess plastic abundance and composition. Monitoring waste disposal on ships and plastic levels in rivers and storm-water runoff helps identify major sources of plastic pollution. Different monitoring approaches are needed to answer different questions, but efforts should be made to standardize methods internationally. The review highlights the importance of standardized protocols, appropriate sampling designs, and the need for long-term monitoring to detect changes in plastic abundance and composition. It also emphasizes the role of seabirds in monitoring small plastic debris and the importance of assessing both the quantity and type of plastic entering the marine environment. Overall, the review underscores the complexity of plastic pollution and the need for a multifaceted approach to monitoring and mitigation.