Ingested Micronizing Plastic Particle Compositions and Size Distributions within Stranded Post-Hatchling Sea Turtles

Abstract

From July 2015 to November 2016, 96 post-hatchling sea turtles were collected from 118 km of the Atlantic coastline in Florida, USA, including loggerhead, green, and hawksbill sea turtle species. Forty-five of the recovered turtles were rehabilitated and released, but the remaining 52 died and were frozen. At necropsy, the gastrointestinal tracts of most the turtles contained visible plastic, and collected particles of 27 individuals were chemically characterized by Raman microscopy as polyethylene, polypropylene, polyethylene terephthalate, and polystyrene. Mesoparticle plastic fragments 1.0-8.7 mm, microparticle fragments 20-1000 μm, and nanoparticles 5-169 nm were identified in the turtles. Polyethylene and polypropylene were the most common plastics ingested from specimens representing 54.1 and 23.7% of the total observed mesoparticles and 11.7 and 21.0% of the total observed microparticles, respectively. A plastic-to-body mass ratio of 2.07 mg/g was determined for this group. The authors suggest that ingestion of micronizing plastic by post-hatchling sea turtles is likely a substantial risk to survival of these endangered and threatened species. This study also provides some of the first evidence for the formation of nanoscopic plastic particles that we theorize forms in the post-hatchling and juvenile environment and are present post-ingestion.

Microplastic ingestion ubiquitous in marine turtles

“…The polymers identified through FT-IR analysis reflect the recently reported polymer diversity globally described for microplastics (Gago et al, 2018). PE and polypropylene (PP) are some of the most abundant polymers found as pollutants worldwide (Gago et al, 2018;White et al, 2018). Furthermore, | 747 applications such as encapsulation (Labriola, Mathiowitz, & Darling, 2017).…”

“…The polymers identified through FT‐IR analysis reflect the recently reported polymer diversity globally described for microplastics (Gago et al, ). PE and polypropylene (PP) are some of the most abundant polymers found as pollutants worldwide (Gago et al, ; White et al, ). Furthermore, Suaria et al () identified 16 classes of synthetic material from the surface waters of the central‐western Mediterranean Sea.…”

“…Knowledge relating to the incidence of microplastic (<5 mm) ingestion in marine turtles still remains very limited, despite records of all seven species of marine turtles ingesting macroplastics (>5 mm) (Boyle & Limpus, 2008;Hoarau, Ainley, Jean, & Ciccione, 2014;Lynch, 2018;Nelms et al, 2016;Schuyler, Hardesty, Wilcox, & Townsend, 2014;Yaghmour et al, 2018) and the creation of global risk maps aiding in the identification of interaction hotspots (Schuyler et al, 2015). The only exception is the isolation of seven microplastic particles (<5 mm) from the gut contents of two green (Chelonia mydas) turtles from the Great Barrier Reef (Caron et al, 2018) and recent accounts relating to stranded posthatchlings from the Atlantic (White et al, 2018).…”

Disease risk analysis in sea turtles: A baseline study to inform conservation efforts

“…Macroplastic ingestion is ranked at the same level as other anthropogenic pressures such as by-catch [ 112 ]. The risk of plastic ingestion has been documented for decades and has affected different age groups of sea turtles [ 113 – 115 ]. As a result, in post hatchlings and juvenile turtles, gastrointestinal impaction or injury directly affect the health and reduced nutrient intake or abnormal buoyancy indirectly impair the fitness [ 113 ].…”

“…The risk of plastic ingestion has been documented for decades and has affected different age groups of sea turtles [ 113 – 115 ]. As a result, in post hatchlings and juvenile turtles, gastrointestinal impaction or injury directly affect the health and reduced nutrient intake or abnormal buoyancy indirectly impair the fitness [ 113 ]. Generally, the risk of macroplastic ingestion is documented more than microplastics and in some cases is reported to have higher impacts.…”