Marine aquaculture extensively relies on plastic products such as buoys, nets and ropes, which undergo continuous aging under ultraviolet radiation, hydrodynamic forces, salinity and biofouling. Progressive aging accelerates both the generation of secondary microplastics and the release of plastic-derived additives, making aquaculture plastics an important yet underrecognized source of particulate and dissolved contaminants in coastal environments. However, current replacement strategies are still primarily based on structural failure rather than the environmental risks associated with plastic aging, owing to the lack of a rapid and field-applicable assessment of plastic aging degree. This study proposes an integrated framework that links plastic aging degree with particulate and dissolved pollutant release. A multimodal field assessment system is developed by integrating morphological characteristics, spectroscopic information, color variation and surface properties to quantify the aging degree of marine aquaculture plastics. A global in-situ exposure experiment and an aging database are being established to support model calibration and validation. Based on the identified aging degree, laboratory simulations will quantify the release kinetics of secondary microplastics and plastic additives from representative aquaculture plastic products under different aging stages, thereby establishing the relationships between aging degree, pollutant release and environmental service life. This framework provides a scientific basis for predicting pollutant release and environmentally safe service life of marine aquaculture plastics.