The Korea Institute of Ocean Science and Technology (KIOST; Kim Woong-seo , president) confirmed that 28 of 34 carcasses of four sea turtle species^* that were bycaught, stranded, or drifted and died off the coast of Korea had ingested marine plastics. The majority of the plastics were disposable packaging materials from land and fishing waste.

* Loggerhead sea turtles (Caretta caretta), green sea turtles (Chelonia mydas), olive ridley sea turtles (Lepidochelys olivacea), and leather-back sea turtles (Dermochelys coriacea)

Currently, there are seven species of sea turtles around the world, which are categorized and managed according to at-risk level by the International Union for Conservation of Nature (IUCN), an international environmental organization. A Convention on Biological Diversity (CBD) report^* included loggerhead sea turtles and green sea turtles among the six marine species most affected by plastic feeding and entanglement.

* Convention on Biological Diversity (CBD), 2012, “Impacts of Marine Debris on Biodiversity: Current Status and Potential Solutions.”

In this regard, KIOST is striving to protect sea turtles that inhabit the coast of Korea through cooperation with a variety of related organizations as a way to participate in related international community efforts.

The research team, led by senior researchers Shim Won-joon and Hong Sang-hee at the Risk Assessment Research Center of the KIOST South Sea Research Institute, are analyzing the amount and nature of plastic waste found in the digestive tracts of sea turtle carcasses in cooperation with the Marine Biodiversity Institute of Korea and the National Institute of Ecology to evaluate plastic consumption by sea turtles.

The three organizations have been conducting joint autopsies of sea turtle carcasses since 2017 and in April 2022 officially launched the Collaborative Sea Turtle Research Group .

Recently, the Research Group conducted joint autopsies^* on a total of 61 sea turtle carcasses found off the coast of Korea^** and published the results of 34 of them in an international scientific journal^*** in February 2022. According to the research, a total of 1,280 plastic fragments (118g total) was found in 28 of 34 sea turtles, which means that each sea turtle consumed an equivalent of 38 fragments (3g) of marine plastic.

* Microplastics 1 mm or greater in size and medium and large plastics were analyzed in the contents of sea turtle digestive tracts.

** East coast (Goseong, Sokcho, Yangyang, Gangneung, Samcheok, Yeongdeok, Pohang, Gyeongju, and Ulsan), South coast (Busan, Jeju), West coast (Taean)

*** Moon, Ye-lim et al. (KIOST), Environmental Pollution, April 2022 Issue (Title: What type of plastic do sea turtles in Korean waters mainly ingest? Quantity, shape, color, size, polymer composition, and original usage)

The predominant forms of plastic were film (42%) and fiber (39%), the main colors were white (42%) and clear (23%), while the main material types were polyethylene (51%) and polypropylene (35%). Numerous film packaging materials (19%), plastic bags (19%), strings (18%), nets (16%), and ropes (11%) were identified.

Plastic fibers were predominant in herbivorous sea turtles while plastic films were predominant in omnivorous sea turtles, confirming differences in ingestion according to species’ feeding habits.

In addition, KIOST is promoting the development of technology to assess the impact of plastic waste on marine ecosystems to investigate the effects of marine plastic debris (MPD).

The research involves the study of floating medium and large plastic waste pollution, entanglement and impact on feeding of marine organisms, migration of alien species, pathogens attached to plastics, and habitat loss.

“Protecting sea turtles, an internationally endangered species, and evaluating the current status and characteristics of sea turtle plastic consumption as an indicator of overall marine plastic pollution are important and worthwhile tasks. This will serve as an opportunity to raise awareness of the importance of the marine environment,” stated KIOST President Kim.

Senior researcher Hong stated, “The autopsies of sea turtle carcasses show the effect of marine plastics on sea turtles living along Korea’s coast and the actual situation of marine pollution.” He emphasized, “Action is needed to reduce marine debris, including everyday waste generated on land and fishing gear thrown away while fishing in rivers or sea.”