Sorption, Extraction, and Characterization of Polycyclic Aromatic Hydrocarbons in Environmentally Weathered Microplastics, Particulate Organic Matter, Sediment, and Fish Species in the Lavaca-Matagorda Bay System

Abstract

The historical industrial input of polycyclic aromatic hydrocarbons (PAHs) and, more recently, microplastics into the Lavaca-Matagorda Bay system is a threat to its health and the region’s fishery economy. Our study assessed the role of microplastics in PAH mobility within Lavaca-Matagorda Bay. We investigated concentrations of the EPA’s 16 high-priority PAHs on microplastics, particulate organic matter, and surface sediments. Additionally, the gastrointestinal tracts of three economically important fishes within the bay [Paralichthys lethostigma (n = 46), Sciaenops ocellatus (n = 47), and Cynoscion nebulosus (n = 85)] were examined for microplastics, while their liver and muscle tissue were analyzed for PAHs. In all three matrices, the average concentration of ∑16PAHs ranged from 890.2 to 28,574.0 ng·g^–1. The average individual PAH concentration in fish species ranged from 75.1 to 145.4 ng·g^–1. Fish species in all of the sampling sites were classified between minimally and moderately polluted, with potential PAH bioaccumulation observed only in the southern flounder. About 67% of all of the analyzed sediment samples from Lavaca-Matagorda Bay indicate possible adverse or moderate adverse biological effects. This demonstrates the need for greater remediation of the existing pollution and continued monitoring of industrial discharges within Lavaca-Matagorda Bay to reduce harm to the ecosystem and the local economy.