Effects of microplastics ingestion on fish brains: A case study with gilthead seabream (Sparus aurata L.)

Abstract

[eng] Nowadays, microplastics (MPs) and the adsorbed pollutants (POPs) are considered a global thread to marine ecosystems. This study describes the effects of POPs and MPs ingestion on fish brains through the assessment of oxidative stress biomarkers and monoaminergic neurotransmitters on gilthead seabream (Sparus aurata). Juveniles were submitted to three different dietary treatments: Control (C), Virgin MPs (V) and Marinated MPs (M). C treatment consisted of standard feed, V treatment contained feed enriched with 10% of MPs and M treatment was composed of feed with 10% of MPs and was exposed to seawater in an anthropogenic impacted sea area for 2 months in order to enrich the plastic with the pollutants associated to the water column. Sampling was made at 0 days from the start of the experiment (T0), at the end of the enriched died (90 days, T90) and after a 30-day detoxification period (T120). Results evidenced that a MPs and POPs enriched diet increases the activity of some of the oxidative stress biomarkers (CAT and GST). In addition, this study reported for the first time alterations on dopaminergic and serotonergic system activities on seabream brains, indicating potential neurofunctional effects from MPs ingestion. Moreover, results showed a tendency to recover enzymatic and brain monoaminergic neurotransmitter levels after a 30- day depuration period.