Fish and shellfish expose to mercury (Hg) from environmental sources and anthropogenic activities. Methylmercury is the highly toxic form of Hg and along with Hg, this form can cause severe health problems harming organs and systems in the body at all ages. Sea bream (Sparus aurata), sea bass (Dicentrarchus labrax), and mussel (Mytilus galloprovincialis) are the most exported species in addition to being consumed frequently in the country. According to 2021 aquaculture data from the Turkish Statistical Institute, the total production rates of sea bream, sea bass, and mussel were 133476, 155151, and 4585 tonnes, respectively. Since Hg can be transmitted to farmed fish from the aquaculture environment or through feed, periodic sampling enables reducing contamination risks. The aim of this study is to investigate the control and presence of mercury risk levels originating from fish farms.
Sea bream, sea bass, and mussel samples were collected from 5 different regions throughout 2020-2021. Fall, winter, spring, and summer samplings were carried out from 6 different fish farms and 2 different mussel farms. Total of 51 samples were analyzed. The Hg analyzes were performed with NIC MA-3SOLO Analyzer (Nippon Inst. Co., Japan) by using the Direct Thermal Decomposition - Gold Amalgamation - Cold Vapor Atomic Absorption Spectroscopy (CVAAS) technique.
The minimum and maximum Hg values were 0.014-0.049 ppm for sea bream, 0.015-0.057 ppm for sea bass, and 0.006-0.013 ppm for mussel samples. The Hg levels of mussels among all samples were the lowest in all seasons. According to European Commission Regulations, the trace metal limit of Hg is 0.5 mg kg-1 (ppm) in fishery products. In this study, none of the samples exceeded the limit value determined for Hg. It was revealed that consuming farmed fish and mussels did not pose a risk in terms of food safety for mercury-related health problems. Yet, continuous monitoring studies are of great importance in determining the relationship between aquaculture products and toxic metals.