We used Naturalist’s rectangular dredge to collect samples of seabed debris along Taiwan’s west coast from 2019 to 2022. There were eight sites with an average depth of 10- 30 meters. Among the results, the samples from Donggang River estuary in Pingtung County had the highest dry weight (2,543 g), accounting for 48% of all samples. Fiber fabrics (58%) and film plastics (33%) accounted for the largest proportion of all samples, and fiber fabrics from Gaoping River estuary (83%) and Donggang River estuary (75%) accounted for more than 70% of all samples at each site. However, there were no significant differences in the proportions of wastes in different quarters. This study monitors the distribution and composition of underwater trash over a long period of time.