Citation: Tamer T, Radivoj P, Jelana B, Milena Ž, Dragan S, Dragana L, Nikola P . Persistent Organic Pollutants and Heavy Metals and the Importance of Fish as a Bio-Indicator of Environmental Pollution. Con Dai & Vet Sci 2(2)- 2018.CDVS. MS.ID.000131. DOI: 10.32474/CDVS.2018.02.000131. 168 Opinion Nowadays water pollution is the burning issue all over the world. Aquatic ecosystems are frequently contaminated with different toxicants through anthropogenic activities, and some of them such as metals may be naturally present and essential in low concentration but toxic and harmful in higher concentrations. Having in mind that not all chemical forms of pollutants are equally bioavailable, and some pollutants can be accumulated in living organisms to a greater extent than others, there is a need to study the levels of pollutants in the organisms to be able to predict the environmental risk. Thus, chemical analyses of the tissues of aquatic organisms are used as a routine approach in studies of aquatic pollution, providing a temporal integration of the levels of pollutants with biological relevance at higher concentrations than those present in water or sediment, and facilitating their quantification [1]. Fish are among the group of aquatic organisms which represent the largest and most diverse group of vertebrates. A number of characteristics make them excellent experimental models for toxicological research, especially for the contaminants which are likely to exert their impact on aquatic systems [2]. Due to feeding and living in the aquatic environments fish are particularly vulnerable and heavily exposed to pollution because they cannot escape from the detrimental effects of pollutants. Fish, in comparison with invertebrates, are more sensitive to many toxicants and are a convenient test subject for indication of ecosystem health. Heavy metals are produced from a variety of natural and anthropogenic sources. In aquatic environments, heavy metal pollution results from direct atmospheric deposition, geologic weathering or through the discharge of agricultural, municipal, residential or industrial waste products. Heavy metals are able to disturb the integrity of the physiological and biochemical mechanisms in fish that are not only an important ecosystem component, but also used as a food source. Previous studies have shown that marine and farmed fish and shellfish are significant contributors to consumer intake of some contaminants due to their presence in the aquatic environment and their accumulation in the flesh of fish and shellfish. The objective of this article is to describe the effects of different persistent organic pollutants and heavy metals on the fish used as bioindicator of environmental pollution. Fish have been found to be good indicators of water contamination in aquatic systems because they occupy different trophic levels; they are of different sizes and ages and in comparison with invertebrates, are also more sensitive to many toxicants [3]. Last but not least, fish are the final chain of aquatic food web and an important food source for human. Therefore, some toxicants in aquatic environments can be transferred through food chain into humans. Persistent Organic Pollutants and Teir Efect on Fish Target Organs Gills The fish gills are multifunctional organs involved in ion transport, gas exchange, acid–base regulation and waste excretion. Given that the gills accounts for well over 50% of the surface area of a fish it is not surprising that one of the major target organs for waterborne toxicants is the gill. The gills are regarded as the important site for direct uptake from the water, whereas the body surface is generally assumed to play a minor role in xenobiotics uptake of fish. Thus, in teleost fish the gills are most frequently utilized in bioaccumulation studies and the pathological damage Persistent Organic Pollutants and Heavy Metals and the Importance of Fish as a Bio-Indicator of Environmental Pollution Tamer Tashla 1 , Radivoj Prodanović 1 , Jelana Bošković 1 , Milena Žuža 2 , Dragan Soleša 1 , Dragana Ljubojević 3 and Nikola Puvača 1 * 1 Department of Engineering Management in Biotechnology, University Business Academy, Faculty of Economics and Engineering Management, Serbia 2 John Naisbitt University, Faculty of Bio farming, Serbia 3 Scientific Veterinary Institute “Novi Sad”, Serbia Received: October 16, 2018; Published: October 22, 2018 *Corresponding author: Nikola Puvača, University Business Academy, Faculty of Economics and Engineering Management, Department of Engineering Management in Biotechnology, Novi Sad, Serbia UPINE PUBLISHERS Open Access L Concepts of Dairy & Veterinary Sciences Opinion ISSN: 2637-4749 DOI: 10.32474/CDVS.2018.02.000131