Interaction between loggerhead sea turtles (Caretta caretta) and marine litter in Sardinia (Western Mediterranean Sea)

• This is the first study on interaction between sea turtles and litter in Sardinia.
• White sheet items are the most ingested plastic sub-category.
• This study will be useful for the implementation of the MSFD monitoring programs.
• Our results support the choice of C. caretta as bio-indicator for Mediterranean.

Anthropogenic debris in the environment affects many species that accidentally ingest it. The aim of this study is to evaluate the quantity and composition of marine litter ingested by loggerheads in Sardinia, thus supplying for the lack of data in the existing literature for this area. Seventeen of the 121 (14.04%) monitored turtles presented debris in their digestive tracts. Litter in faecal pellet of alive individuals (n = 91) and in gastro-intestinal contents of dead ones (n = 30) was categorized, counted and weighed. User plastic was the main category of ingested debris with a frequency of occurrence of 13.22% of the total sample, while sheet (12.39%) and fragments (9.09%) were the most relevant sub-categories. This study highlights for the first time the incidence of litter in alive turtles in Sardinia. This contribution improves the knowledge about marine litter interaction on Caretta caretta as bio-indicator. Results will be useful for the Marine Strategy implementation.