Farmed Turkish salmon: Toxic metals and health threat

Introduction. Toxic metals in fish, even at low levels, have negative consequences for human health. Even essential metals pose a health threat if consumed in certain quantities. Mercury, cadmium, and lead are the most frequent metals containing in fish. The research objective was to inspect the quality of aquaculture fish found in most major grocery chains across Turkey. Study objects and methods. The present research featured the quantities of Zn, Fe, Cu, Al, Pb, Hg, and Cd in Turkish salmon. The sampling took place between February and June 2019. The cumulative carcinogenic and non-carcinogenic risk for consumers was evaluated based on trace element levels in a prospective health risk assessment using the U.S. EPA model of lifetime exposure. Results and discussion. Fe proved to be the most abundant element in fish fillets, followed by Zn and Cu. Other elements appeared to be far below the permissible values, namely Al ≤ 0.5, Cd ≤ 0.02, Pb, and Hg ≤ 0.05. All the trace elements detected in Turkish salmon were below the reference dose values. The percent contribution to total risk by Fe, Cu, and Zn were 34.20, 24.80, and 41.01%, respectively. The hazard index was ≤ 1. The contamination of aquaculture fish fillet proved insignificant, and the carcinogenic risk was entirely negligible. Conclusion. The research revealed no hazardous trace elements, and their cumulative effects were not indicated in the hazardous index.

Eutrophication Driven by Aquaculture Fish Farms Controls Phytoplankton and Dinoflagellate Cyst Abundance in the Southern Coastal Waters of Korea

We examined the dynamics of dinoflagellate cyst and phytoplankton assemblages in eutrophic coastal waters of Korea, adjacent to fish and shellfish farms. Water temperature showed seasonality, whereas salinity and pH remained relatively consistent. Dissolved inorganic nutrient levels were higher in September and at the inner stations, where aquaculture fish farms are located than those in May and at the outer stations. Canonical correspondence analysis and artificial neural network analysis revealed multiple environmental factors that affect the distribution of phytoplankton and dinoflagellate cysts. Diatoms dominated in the phytoplankton assemblages, while the protoperidinioid group dominated in the dinoflagellate cyst assemblages. Cyst abundance was higher at the outer stations than at the inner stations due to transport by fast currents, and phytoplankton abundance was positively correlated with cyst abundance. An increase in diatom abundance led to an increase in heterotrophic/mixotrophic cyst abundance, indicating that excessive uneaten food and urinary waste from the fish farms caused eutrophication in the study region and fast growth of diatoms, thereby contributing to the growth of heterotrophic/mixotrophic dinoflagellates and consequently, high abundance of heterotrophic/mixotrophic dinoflagellate cysts.