FACTORS OF ACCUMULATION OF HEAVY METALS IN FISH ORGANISMS

Abstract

The description of the main properties of heavy metals, forms, sources of their accumulation and impact on fish organisms is presented. It was determined that heavy metals have both positive and negative (harmful) effects on hydrobionts. The latter is characterized by the deterioration of the physiological and biological indicators of the vital activity of fish. Heavy metals have a negative impact on the health of people who consume contaminated fish, causing poisoning, diseases of internal organs and the nervous system. Therefore, the topic of accumulation of heavy metals by fish organisms is relevant for scientific research. It is shown that heavy metals have two sources of entry into aquatic ecosystems: natural and anthropogenic. It was established that it is the anthropogenic impact that is larger and has a greater threat in the future, because the modern world is characterized by the rapid development of industry, energy and agriculture, which are the main polluters of ecosystems.The main natural factors affecting the accumulation of heavy metals by fish organisms are characterized, among which the following are highlighted: temperature and water regimes, seasonality, physical and chemical composition of water and physical and biological characteristics of fish (species, age, nutrition). It should be noted that each of the factors affects a certain stage of the accumulation process, and most often the factors act in combination. The problem of increasing water temperature is reflected as one of the main factors influencing the accumulation of heavy metals by hydrobionts. With increasing temperature, the solubility of many metals, such as iron and copper, can increase, this is due to an increase in the kinetic energy of molecules, which contributes to a better dissolution of metals in water. Temperature affects the content of heavy metals in several ways, changing their solubility, mobility, bioavailability and influencing biological and chemical processes in fish organisms. It is noted that in order to maintain fish health, it is important to ensure optimal concentrations of the necessary heavy metals, avoiding their toxic levels. This is achieved through control of aquatic pollution, monitoring of metal levels in water and feed, and understanding of environmental factors affecting bioaccumulation and biomagnification of heavy metals.