This study quantitatively evaluated the durability of fishing gear marking systems and examined the effects of marking type, exposure time, and environmental conditions. Five types of buoys and three types of eel traps were used and attached (PP), adhesive (PP, PET), and insert-type (PP) markers were applied to buoys while rivet-type (PP) and hole cap-type (PP, POM) markers were applied to eel traps. Long-term exposure experiments were conducted under seawater immersion and outdoor exposure conditions. Durability was evaluated using a durability index calculated based on marking loss rate and information recognition rate. No significant differences in durability index were observed among buoy markers according to marking type or environmental condition whereas rivet-type (PP) markers applied to eel traps exhibited the highest durability index across all conditions. However, no significant differences in durability index were observed according to marking type or environmental condition; this indicates that the influence of environmental conditions was limited. In contrast, eel trap markers showed significant effects of marking type and environmental condition on durability index with a significant interaction between exposure time and environmental condition. Rivet-type (PP) markers exhibited the highest durability across all conditions indicating the most stable performance while hole cap markers showed differences depending on material. These findings are expected to provide fundamental data for future fisheries management policies.