High frequency of micro- and meso-plastics ingestion in a sample of neonate sea turtles from a major rookery

Plastic Pollution and Small Juvenile Marine Turtles: A Potential Evolutionary Trap

“…To normalise for turtle size (for those individuals where turtle mass was recorded) the body burden of ingested plastic (g plastic/kg turtle) was calculated following calculations outlined in Clukey et al (2017a) and Lynch (2018). Body condition index (turtle mass kg/SCLˆ3) was also calculated following indices described in Bjorndal et al (2000a) and Rice et al (2021) to compare with measures of plastic burdens. Curved Carapace Length (CCL) to Straight Carapace Length (SCL) conversions were taken from Lynch (2018).…”

“…Regionally, these include the East Australian Current (EAC), Indian Ocean South Equatorial Current (SEC) and the Leeuwen Current (Limpus and Nicholls, 1988;Whiting et al, 2008;Boyle et al, 2009;Feng et al, 2011;Robson et al, 2017;Wildermann et al, 2017;Pattiaratchi et al, 2021). Knowledge indicates that small juveniles are associated within these currents or sites of convergence (Ryan et al, 2016;Pham et al, 2017;Eastman et al, 2020;Rice et al, 2021). Modelling has suggested that active and directed swimming behaviour appears to play a major role in post-hatchling distribution during the first few months of their life (Putman et al, 2012;Scott et al, 2014;Wildermann et al, 2017;Wolanski, 2017) and behaviour therefore influences the adoption of oceanic lifestyles and potential fidelity to discrete oceanic regions (Polovina et al, 2004;Etnoyer et al, 2006;Mansfield et al, 2009;Barceló et al, 2013).…”

“…Indeed within this study, smaller stranded turtles displayed higher body burdens of plastic than large bycaught individuals. To further our understanding it will be crucial to identify methods to measure changes in vital rates specific to locations and life stage, e.g., changes in somatic growth or survivorship (Rice et al, 2021). This will increase knowledge of poorly understood population-level mortality rates (Senko et al, 2020).…”

“…Records of plastic ingestion (> 1 mm) by marine turtles have been reported in the Atlantic (Musick and Limpus, 1997;Witherington, 2002;Mascarenhas et al, 2004;Di Beneditto and Awabdi, 2014;Santos et al, 2016;Colferai et al, 2017;Pham et al, 2017;Rizzi et al, 2019;Eastman et al, 2020;Machovsky-Capuska et al, 2020;Rice et al, 2021), the Pacific (Wedemeyer-Strombel et al, 2015;Ng et al, 2016;Clukey et al, 2017a;Godoy and Stockin, 2018;Jung et al, 2018a), the Indian Ocean (Hoarau et al, 2014;Yaghmour et al, 2018) and the Mediterranean Sea (Tomas et al, 2002;Campani et al, 2013;Camedda et al, 2014;Matiddi et al, 2017;Domènech et al, 2019;Digka et al, 2020). Drivers behind marine debris ingestion have included visual selectivity (Schuyler et al, 2012;Fukuoka et al, 2016;Duncan et al, 2019a), odour (Pfaller et al, 2020), or failure of discrimination when mixed with normal dietary items (Di Beneditto and Awabdi, 2014).…”

“…Small juveniles (including post-hatchlings and oceanic juveniles) are hypothesised as the life stage most likely to be highly impacted by plastic pollution as this life stage is particularly vulnerable to entanglement in floating marine plastic debris (Wilcox et al, 2015;Duncan et al, 2017), damaging effects of ingestion (Clukey et al, 2017a;Pham et al, 2017;Vélez-Rubio et al, 2018;White et al, 2018;Duncan et al, 2019a;Eastman et al, 2020) and sensitive to potential population-level effects (Rice et al, 2021). The consumption of non-nutritional items can lead to dietary dilution resulting in reduced energy and growth (McCauley and Bjorndal, 1999;Nelms et al, 2016), and has been shown to cause damage and blockage to the gastrointestinal tract, cloaca and bladder in some specimen (Bugoni et al, 2001;Lazar et al, 2011;Ryan et al, 2016;Wilcox et al, 2018).…”