Fish are a recommended component of the diet, supplying complete proteins, vitamins, mineral salts, and omega-3 fatty acids. The presence of mercury in fish tissue, both freshwater and marine, is the effect of its accumulation in the aquatic environment and depends largely on the concentration of mercury in water as well as food. Most of mercury in fish tissues is present in the form of organic complexes, mainly methylmercury, which is much more toxic than metallic mercury. In organisms of predatory fish, such as shark, tuna, swordfish, or eel, mercury will be present in concentrations higher than in other species of fish. It is not just the result of their nutrition, but is also related to their age, mobility and habitat. In fish living near the bottom of a water body, the concentration of mercury will be much higher. It has to be noted that the ongoing climate change and increase in environmental contamination may significantly raise the bioavailability of mercury and its organic complexes in fish. Fish that are at the end of a food chain may contain such large amounts of mercury in their organisms that it may pose a threat to human health. This problem is particularly concerning people whose diets are based on fishmeat. The aim of the following paper is to present the current state of knowledge on sources of mercury released into aquatic environments and the related threats to human health with regard to fish consumption. The article takes note of the increasing number of incoming alerts under the European Rapid Alert System for Food and Feed (RASFF), regarding the contamination of fish and fish products with mercury.

28.3.2023