Ingestion of plastic marine litter by sea turtles in southern Brazil: abundance, characteristics and potential selectivity

Abstract

The ingestion of plastic marine litter (PML) by sea turtles is widespread and concerning, and the five species that occur in the southwestern Atlantic - green, loggerhead, olive ridley, leatherback and hawksbill - are vulnerable to this pollution. Here, we quantified and characterized PML ingested by these species in southern Brazil, and observed PML ingestion in 49 of 86 sampled individuals (~57.0%). Green turtles presented the highest rates and variety of ingested plastics, and such ingestion has been high at least since 1997. Omnivorous turtles presented higher PML ingestion than carnivorous ones. Loggerheads displayed a negative correlation between body size and number of ingested items. Green turtles ingested mostly flexible transparent and flexible/hard white plastics; loggerheads ate mainly flexible, hard and foam fragments, in white and black/brown colors. These results help us better understand PML ingestion by sea turtles, highlighting the seriousness of this threat and providing information for prevention and mitigation strategies.

Keywords: Marine plastic pollution; Marine turtles; Negative impacts; Plastic polymers; Prey-specific index; Southwestern Atlantic.