Chemical pollution and ecotoxicological effects of high-density polyethylene microplastics in Mytilus galloprovincialis from two Italian lagoon ecosystems

Navigating a Microplastic Sea: How the Pacific Cupped Oyster (Magallana gigas) Respond to Microplastic Pollution in Lagoons

“…All oysters underwent a 15 day acclimation period to standard environmental conditions, including a salinity of 36‰, pH of 8.12, and temperature of 20 ± 1 °C, as outlined by Provenza et al [ 25 ]. After acclimation, oysters from Orbetello and Varano were assigned to specific treatment groups, following a 2 (location) × 3 (color) × 3 (replicates) design, resulting in 18 treatment groups and one set of negative control triplicates.…”

“…Exposure involved a single concentration (0.05 g/L) of fragmented high-density polyethylene (HDPE) available in three colors: pink, blue, and white. This concentration was chosen based on prior experimental exposure studies conducted on marine mussels ( Mytilus galloprovincialis ) [ 25 ].…”

“…Oysters were exclusively assessed under fed conditions, with a daily introduction of a fish feed mixture into the water at a concentration of 30 mg/L [ 25 ]. The fish feed was pre-tested for the presence of MPs according to the methods described in Section 2.3 , and no MPs were detected.…”

“…This is why they are valuable bioindicators, allowing the assessment of MP contamination levels by measuring their accumulation in oyster tissues [ 21 , 22 , 23 ]. While the risks of human consumption of these MP-accumulating oysters are still under investigation [ 24 ], this study, alongside that of Provenza et al [ 25 ], aims to bridge that knowledge gap. Microplastic analyses were performed in the Magallana gigas (Thunberg, 1793), formerly Crassostrea gigas , collected from the two lagoon systems to define baseline levels of MPs and biochemical biomarkers.…”

“…Moreover, the biochemical effects induced by the exposure of M. gigas to different colors of high-density polyethylene (HDPE) were determined. HDPE was chosen as the model for MPs due to its widespread use and resulting abundance in aquatic environments [ 25 ]. A variety of colors can be found in the aquatic environment, with pink, blue, and white being the most commonly observed in lagoon ecosystems [ 26 , 27 ].…”