Comparison of Microplastics Found Within the Gastrointestinal Tract of Caretta caretta
Megan J. Kelly, University of Salford
Lauren .J. Kageler, Dickinson College
The pollutions of the oceans is a rising concern of environmentalists and researchers worldwide. Plastic production and its usage in several fields, from food packaging over water bottling to clothing, increased in the last years. Being cheap in production and durable over a long time of period may seem a positive aspect for plastic, but once left in the environment, those two characteristics make it one of the most concerning pollution item. Once plastic pieces enter the ocean – transported via wind, fresh water
systems or other anthropogenic sources – they are exposed to salt water, sunlight and water currents and therefore tend to break down into smaller pieces.
These pieces – if they are smaller than 5mm – are so called “microplastics”.
One of the projects of Archipelagos Marine Institute is currently working on the assessment of microplastics content in two loggerhead sea turtles (Caretta caretta) which were washed up on shore less than 10km from each other.
The first individual was stranded on a beach in Pythagorio, Samos Island, in 2010, the second one was found in Psili Ammos in 2017.
An autopsy was carried out followed by a necropsy for both individuals and data of their size and sex was documented. The stomach, large intestine and small intestine was emptied and sieved to remove any plastic or natural sediments larger than 5mm. From this point forward, a filtration process has taken place. The 2017 C. caretta has been fully filtered and is awaiting microscopic analysis, whereas the 2010 C. caretta is currently in the process of filtration.
Astonishingly in the stomach content of the 2017 C. caretta, we identified a 30cm piece of fishing line, with the remains of natural food sources such as crabs and sea urchins.
This project is not only in place to assess microplastics found in the gastrointestinal tract of both turtles, but also to evaluate if the microplastics differ in term of type ingested over the past few years. This project has the potential of being used for future Archipelagos researchers and students, to assess if microplastic digestion will increase within future stranding’s of the C. caretta.