Study on Plastic Ingestion in Carcasses Sea Turtles on Enggano Island, Indonesia

Plastic pollution in the ocean has a harmful impact on marine life and ecosystems including the decline in turtle populations. The decreasing of turtles populations caused by plastic pollution affects the management of regional turtle conservation units. Therefore, the current study was conducted on five green turtles (Chelonia mydas) and five hawksbill turtles (Eretmochelys imbricata) in the transitional and juvenile size range (29–49 cm) that were found dead on Enggano Island, Bengkulu Province. The aim of this study was to assess their consumption of plastic waste. The results showed that macroplastics and microplastics were 100% detected in the intestines of C. mydas and E. imricata. In C. mydas, a total of 164 macroplastic items were found, with the most common category of USE FRA (35.37%). In E. imbricata, 20 macroplastic items were identified, divided into two categories: USE THR (55.56%) and USE SHE (44.44%). Microplastic particles in the digestive tracts averaged from 14 to 18 and from 7 to 12 per 50 grams of sample in C. mydas and E. imbricata, respectively. Those microplastic types were fibers, films, and fragments. In C. mydas, fragments were the most common type of plastic found (65.67%), while fibers were most prevalent in E. imbricata (48.89%). Fourier Transform Infrared (FT-IR) spectroscopy revealed the presence of synthetic polyethylene in both turtle species. In C. mydas, larger individuals showed a higher prevalence of film and fragment microplastics, while E. imbricata was predominantly characterized by fiber microplastics (no significant influence). Turtles are predicted to digest both macro- and microplastic particles either by eating them directly with their food or indirectly through the food chain in areas or migration routes polluted with plastic waste.