This study presents an optimized enzymatic digestion protocol for isolating microplastics from biota-rich marine samples and organisms. The method effectively removes biological material without damaging microplastics, allowing for accurate detection and quantification. The protocol was tested on seawater samples from the western English Channel, revealing 0.27 microplastics per cubic meter. It was also applied to zooplankton samples, identifying microplastics ingested by marine organisms. The enzymatic digestion protocol outperformed acid and alkaline treatments in terms of digestion efficiency and microplastic preservation. The method was validated using known microplastic samples and confirmed its effectiveness in isolating microplastics from various marine environments. The study highlights the importance of standardized protocols for monitoring microplastic pollution in marine ecosystems. The findings suggest that enzymatic digestion is a reliable and efficient method for detecting microplastics in marine biota, with potential applications in future research and environmental monitoring. The results indicate that microplastics are prevalent in marine environments and can be ingested by a variety of organisms, posing potential risks to marine life. The study underscores the need for further research to better understand the impact of microplastics on marine ecosystems and to develop more effective methods for their detection and monitoring.This study presents an optimized enzymatic digestion protocol for isolating microplastics from biota-rich marine samples and organisms. The method effectively removes biological material without damaging microplastics, allowing for accurate detection and quantification. The protocol was tested on seawater samples from the western English Channel, revealing 0.27 microplastics per cubic meter. It was also applied to zooplankton samples, identifying microplastics ingested by marine organisms. The enzymatic digestion protocol outperformed acid and alkaline treatments in terms of digestion efficiency and microplastic preservation. The method was validated using known microplastic samples and confirmed its effectiveness in isolating microplastics from various marine environments. The study highlights the importance of standardized protocols for monitoring microplastic pollution in marine ecosystems. The findings suggest that enzymatic digestion is a reliable and efficient method for detecting microplastics in marine biota, with potential applications in future research and environmental monitoring. The results indicate that microplastics are prevalent in marine environments and can be ingested by a variety of organisms, posing potential risks to marine life. The study underscores the need for further research to better understand the impact of microplastics on marine ecosystems and to develop more effective methods for their detection and monitoring.