Debris ingestion and nutritional niches in estuarine and reef green turtles

Little attention has been drawn toward the effects of marine debris ingestion in relation to nutrient acquisition and fitness consequences. We tested whether anthropogenic debris ingestion influence the nutritional niches of endangered green turtles (Chelonia mydas) in estuarine and reef habitats on the Brazilian coast. Our results showed that estuarine turtles consumed diets with lower proportional wet mass composition of protein (P) and water (W) than their reef conspecifics. The amounts of debris, mostly plastics, retrieved from the digestive tracts of estuarine turtles were higher compared with those individuals from reefs. The realized nutritional niche from estuarine turtles was subject to the debris density in the environment, lack of benthic food resources available and the surface foraging behavior, likely preventing them from reaching their nutritional goals and resulting in lower fitness. The study provides critical information for the management and conservation of ecologically threatened individuals, populations, and their natural habitats.