Ingested plastics as a transport medium for marine toxicants to enter the gastrointestinal tract of loggerhead sea turtles (Caretta caretta)
Presentation
Overview
Overview
Description
A growing demand for plastic and its improper disposal has led to its accumulation within ocean convergence zones. Loggerhead sea turtles (Caretta caretta) migrate through convergence zones and have been shown to ingest plastics; however, the toxicological effects of plastic ingestion are not well understood. This study investigated the presence of toxicants on marine plastic samples collected from Bermuda, the Sargasso Sea, and the North Atlantic Ocean. Among other toxicants, plastic additives such as phthalates and indene were found. This study also examined the ability of pre-production plastic pellets to adsorb and desorb polycyclic aromatic hydrocarbons (PAHs), which are organic pollutants formed by incomplete combustion of fossil fuels. Polypropylene and polyethylene plastic polymers were spiked with six different PAHs, and subsequently washed in organic solvents. Gas chromatography/mass spectrometry (GC/MS) revealed the presence of PAHs in the organic solvent washes, suggesting that PAHs were successfully adsorbed by the plastic pellets. Furthermore, the study investigated the ability of sea turtle gastrointestinal fluids to extract PAHs from plastic. PAH-spiked plastic pellets were shaken and incubated in fluids from the stomach, small intestine, and large intestine of a loggerhead sea turtle for three days at 27.5°C to simulate digestion. After removal of the plastic pellets and extraction of the digestive fluids, GC/MS revealed the presence of these PAHs, suggesting that the PAHs were successfully extracted by the gastrointestinal fluids. From this outcome, it can be concluded that in addition to digestive blockage and nutrient dilution, ingested plastics can leach toxic chemicals into the gastrointestinal tract of loggerhead sea turtles during the digestion process. This could have important conservation implications and should be further investigated.
