Macro and microplastics regurgitated by southern giant petrels (Macronectes Giganteus) at breeding colonies from Patagonia, Argentina

LUCIANA GALLO; LUCAS S. RODRÍGUEZ PIRANI; A. LORENA PICONE; ANA GEREZ; ROSANA M. ROMANO; CARLOS O. DELLA VÉDOVA; MARCELA UHUART

Mar del Plata

Congreso; VIII Congreso Argentino de la Sociedad de Toxicología y Química Ambiental; 2022

SETAC

Plasticdebris is widespread, and it has accumulated worldwide in the marineenvironment. In this study, we analysed regurgitated boluses fromSouthern Giant Petrels (Macronectesgiganteus, SGP) at Gran Robredo and Arce islands, Chubut, Argentina, duringlate chick rearing of two breeding seasons (2020-2021). Plastic items >1mm (microand macroplastics) were found in 29.3% (12/41) of boluses (mean abundance ± SD:0.97 ± 3.33 items, 0.04±0.15 grams; mean intensity ± SD: 3.63 ± 5.81 items, 0.16± 0.27 grams). The most common plastic items were foam (52.5%), followed by film(17.5%), rigid fragments (15.0%), other types of plastic (e.g. cigarettefilters; 12.5%) and pellets (2.5%). We identified the polymer types of the itemsrecovered by Attenuated Total Reflection-Fourier Transform InfraredSpectroscopy (ATR-FTIR) and Raman Microscopy. Polystyrene was the most abundantpolymer (53.8%), followed by polypropylene (12.8%), low density polyethylene (12.8%),cellulose acetate (10.3%), polyamide (7.7%), and high-density polyethylene (2.6%).The frequency of occurrence (FO), intensity, and abundance of plastic items inboluses were lower than those found in stomach content from beach-wreckedcarcasses (all age classes: FO= 59.3%, abundance: 4.0 ± 5.9 items, intensity:6.8 ± 6.4 items; Gallo et al. in prep). This may be due to the retention ofplastics in the ventriculus of petrels because of anatomical features of their gastrointestinaltract. However, the type of plastics found in both types of samples was similar;with film, rigid fragments, and foam the most common categories. Thus, ourfindings confirm that plastic ingestion is a common threat for SGP in theSouthwest Atlantic Ocean. In this sense, SPG boluses are valuable as non-invasivesamples for the detection of changes in the composition and abundance of marineplastics debris to which they are exposed. In addition, the characterization ofingested plastic polymers provides information on pollution sources as well aspotential toxicity derived from plastic additives and leaching.