Trophic ecology and incidental ingestion of microplastics in fish (Sciaenidae) and its relationship with environmental dynamics in Tumaco Bay, Colombian Pacific

Abstract

The Sciaenidae family of fish is important for trade and food sovereignty for the inhabitants of Tumaco Bay, Colombian Pacific. However, there are few studies on its trophic habits in this bay. In this sense, our objective was to determine the trophic ecology and incidental ingestion of microplastics in the Sciaenidae family, as well as its relationship with the environmental dynamics on Tumaco Bay. We collected four samples (2020-2021) with artisanal fishing gear (hook and line, trawl net, gillnet), capturing 467 individuals. Then, we examined the stomach content of the fish and weighed and classified the food items. We estimated the prey preference, similarity, and diet spatiotemporal differences in each species and the association between diet and environmental factors. We found that crustaceans represented a constant food item (92%) of high importance (80%) for most species. Besides, the highest crustacean consumption occurred in the outer zone of the estuary, associated with higher salinity, dissolved oxygen, and transparency, which favors the abundance and richness of this item. On the other hand, incidental consumption of microplastics was detected in 30 specimens belonging to 10 species (70% of them are of commercial interest). We concluded that crustaceans, a common and abundant food resource in Tumaco Bay, are presently exploited, but the presence of microplastics in fish was evidenced.