From factory to table: Assessment of combined industrial pollution on three economically relevant fishes within the Matagorda Bay system of Texas: S. Ocellatus, C. Nebulosus, and P. Lethostigma

• Main Author: Myers, Jessica T.
• Other Authors: Conkle, Jeremy, Bahr, Keisha, Walther, Benjamin
• Format: Thesis
• Language: English
• Published: 2022
• Subjects: fish; impacts; industry; mercury; plastic; pollution; Sciaenops ocellatus
• Online Access: https://hdl.handle.net/1969.6/95071

Mercury ranks as one of the top three toxic substances. Aquatic wildlife and humans face adverse health effects when exposed to it in the form of methylmercury. The mass output of hazardous waste has resulted in an EPA Superfund Site for mercury on the edge of Lavaca Bay, the northernmost subset of the Matagorda Bay system. Additionally, heavy release of pre-production resin pellets (nurdles) was discharged into the bay within the last two decades. Due to their chemical properties, there is potential for mercury to bind to the discharged pellets as well as typical debris seen in all environments. Sorption to plastic may allow for mercury to travel greater distances throughout the bay, resulting in higher mercury concentrations in the fish within this semi-closed system. A sample of 178 fish (Sciaenops ocellatus, n = 47; Cynoscion nebulosus, n = 85; and Paralichthys lethostigma, n = 46) was opportunistically collected from anglers fishing within the Matagorda Bay System. Muscle and liver tissue samples, as well as digestive tracts, were removed from each fish. Digestive tracts were dissected, removing any suspected plastic visible to the human eye (>1mm). Mercury concentrations (wet weight; µg g-1 ) of each tissue type and plastic found within the gut were measured in efforts to observe any trends in plastic consumed and mercury concentrations of the fish. No plastic debris (>1mm) was observed in the sampled digestive tracts, inhibiting the analysis of one of the objectives. The study determined mercury concentrations of three economically relevant fish, categorize them by FDA Consumer Advisory levels, and assess a factor of health via hepatosomatic index (HSI). Data from this study will be used to inform the public affected by the pollution in this area and can inform policy and regulations regarding safe consumption limits and reporting efforts. Physical and Environmental Sciences College of Science and Engineering