Plastic is predicted to cause the most significant damage to marine ecosystems as it flows into the ocean through rivers. The impact of marine plastic on large marine animals can be considered from two major perspectives. One is the problem of ghost fishing caused by large animals getting entangled in marine plastics, primarily discarded fishing gear. The other is the issue of animals ingesting various types of plastic. The Marine Zoology Laboratory at Inha University conducted a study focused on sea turtles to investigate the situation of discarded fishing gear, which is a leading cause of bycatch and stranding. More than 70% of the trash discarded in the waters of Jeju Island is fishing gear, with fishing lines and lures being the most commonly found items. The fact that fishing gear is frequently found in areas where sea turtles are often stranded highlights the seriousness of the issue. Sea turtles often mistake plastic for food and swallow it. In an experiment with hawksbill sea turtles, it was found that they prefer yellow plastic, and individual differences were observed in their ability to distinguish between plastic bags and real food. It has been revealed that much of the plastic in the ocean exists in the form of microplastics, which mix with the food of large marine animals and are found in their stomach contents. The more microplastics they ingest, the higher the risk of absorbing other toxic chemicals like BPA. A comparison of the microplastics found in the lung and stomach tissues of finless porpoises revealed that the proportion of microplastics containing more toxic chemicals was higher in the lungs. Large marine animals serve as a mirror for the impact of plastic on humans, as they occupy a similar ecological position to us. Therefore, more research is needed not only for the conservation of marine animals but also for the protection of human health.

marine plastic,sea turtles,finless porpoises,microplastic,toxic chemicals,bioconcentration,ghost fishing