Marine wildlife ingests plastic pollution, making them a reservoir for plastic debris and an important part of “where is all the plastic?”. To date, estimates of how much plastic pollution resides within marine animals globally are missing, making it difficult to reconcile the fate of plastic pollution in the global ocean. To help fill this knowledge gap, Zhu et al. (2023) collected data on the amount of plastic debris found in sea turtles necropsy studies from the scientific literature up until January 1, 2020. We used this data, along with predictor variables, in a regression model to quantify how much plastic resides within green turtles (Chelonia mydas) globally for a snapshot in time. We found that geographic, socio-economic, and ecological indicators significantly correlate with how much plastic pollution is found in sea turtle gastrointestinal tracts. The Zhu et al. (2024) model suggests that leatherback turtles (Dermochelys coriacea) contain the most plastic in their gastrointestinal tracts, and loggerhead turtles (Caretta caretta) contain the least. This presents one of the first attempts to understand which sea turtle species have the highest propensity for plastic ingestion. We also provide the first estimate of a global marine animal reservoir of plastic pollution: we estimate that at any given time, green turtles carry 7.5-8.2 tonnes of plastic globally in their gastrointestinal tracts.
Zhu X , Rochman C , Mazloff M. 2024. Marine Animals as a Global Reservoir of Plastic Pollution: A Case Study on Sea Turtles. Journal of Geophysical Research: Oceans. DOI: 10.22541/essoar.171742848.86603578/v1
