Marine Debris and Trace Metal (Cu, Cd, Pb, and Zn) Pollution in the Stranded Green Sea Turtles (Chelonia mydas)

Marine debris and trace metals are among the common environmental contaminants known to affect marine organisms. In this study, the quantitative and qualitative aspects of marine debris levels and bioaccumulation of trace metals (Cadmium: Cd; Copper: Cu; Lead: Pb; and Zinc: Zn) were investigated in 42 green sea turtles (Chelonia mydas) stranded on the northern coast of the Sea of Oman. The greatest quantity of debris was found in the intestine, stomach, and esophagus of the animals, respectively. Results of a Marine Strategy Framework Directive (MSFD) subcategory analysis of the ingested debris showed that sheet and thread-like plastics were the most frequently detected debris followed by various rubbish. The results revealed that white-colored debris were the most common debris, followed by black > green > blue > transparent > and brown ones. The results suggested that the rope monofilament was the main source of the ingested debris by the green sea turtles. Concentrations of the trace metals in the liver, kidney, and muscle ranged between 0.66-33.43, 0.36-15.12, and 0.33-7.47 mu g/g (ww), respectively. The results of this study suggest that ingested marine debris and tissue concentrations of trace metals are present at levels that may cause sublethal effects on green sea turtles (C. mydas) through potentially affecting the physiological processes and making the turtles susceptible to other natural or human threats. Results indicated that the green sea turtles from the northern coast of the Sea of Oman have high interaction with the marine debris. These factors are considered as a serious threat to the existence and survival of the green sea turtles (C. mydas) living on the northern coast of the Sea of Oman.