Assessment of the ingestion of anthropogenic debris by green turtles along the south-central coast of Rio de Janeiro, Brazil

Abstract

Among the various forms of pollution, anthropogenic debris has been widely documented to cause entanglement and premature death of sea turtles, in addition to being ingested by these animals. One of the most affected species is the green turtle, which is commonly found along the south-central coast of Rio de Janeiro (RJ), an area characterized by high human population density. This study aimed to assess the impact of anthropogenic debris on green turtles by analyzing the gastrointestinal tracts of 66 individuals stranded along the south-central coast of RJ, as documented by the Santos Basin Beach Monitoring Project. Pieces of debris (1,683 in total) were found in 69.7% of the individuals analyzed, with the highest concentration observed in the large intestine. The most common types of debris were flexible plastic waste (50.5%; 850 items) and amber/brown debris (36.5%; 614 items) within the size range of 0.5 mm to 2.5 cm (41.2%; 693 items). No significant differences in debris composition were observed between turtles encountered inside and outside the bays. The substantial number of individuals with debris in their gastrointestinal tract underscores the severity of the impact of these debris on sea turtles in this region.