Influence of trophic overlaps and trophic niche amplitude on microplastic intake of fish species in shallow areas of a neotropical coastal lagoon.

Plastic pollution is a global challenge that affects all marine ecosystems, and reflects all types of uses and activities of human society in these environments. In marine ecosystems, microplastics and mesoplastics interact with invertebrates and become available to higher predators, such as fish, which can ingest these contaminants. This study aimed to analyze how ecological food interactions (diet overlap and trophic niche amplitude) among fish species contribute to the ingestion of plastic particles. The gastrointestinal contents of six fish species (Atherinella brasiliensis, Eucinostomus melanopterus, Eucinostomus argenteus, Genidens genidens, Coptodon rendalli, and Geophagus brasiliensis) were analyzed to identify prey items and plastic ingestion. Based on the ontogenetic classification, A. brasiliensis, E. melanopterus, and G. genidens were divided into juveniles and adults, and the six fish species analyzed were divided into nine predator groups. Most of the plastics ingested by the fish species were blue microplastic (MP) fibers (< 0.05 mm) classified as polyester terephthalate, polyethylene, and polybutadiene. Considering all the analyzed predators, the average number and weight of plastics ingested per individual were 2.01 and 0.0005 g, respectively. We observed that predators with a high trophic overlap could present a relationship with the intake of MP fibers owing to predation on the same resources. In addition, we observed the general pattern that when a species expands its trophic diversity and niche, it can become more susceptible to plastic ingestion. For example, the species with the highest Levin niche amplitude, E. argenteus juveniles, had the highest mean number (2.9) of ingested MP fibers. Understanding the feeding ecology and interactions among species, considering how each predator uses habitats and food resources, can provide a better understanding of how plastic particle contamination occurs and which habitats are contaminated with these polluting substances.

Feeding ecology and ingestion of plastic fragments by Priacanthus arenatus: What's the fisheries contribution to the problem?

Atlantic Bigeye (Priacanthus arenatus) is a demersal species from the Priacanthidae family with little literature relating to its biology and catch aspects. Due to this lack of research, the focus of this effort was to describe the feeding preferences of Atlantic Bigeye and to evaluate the influence of plastic debris derived from the local fisheries activities on its diet. The most important items were Corophiidae, Penaeidae, Actinopterygii, Isopoda, Cephalopoda, Policheta and plastic. Plastic was present in 49.17% of the stomachs analyzed. A total of 210 plastic fragments were found, and 63% were derived from fishing. Of those, 55% were derived from paint fragments from vessels and 8% from synthetic fibers (PA). The results suggest that plastic fragments found in stomachs are related to the species' natural diet and that this debris is locally deposited in the coastal environment. Fishing resources appear to have been affected by this local marine pollution.