ABSTRACT
Heavy metals are introduced into water due to anthropogenic activities and can significantly affect an entire ecosystem. Due to their close integration with the water environment, fish are a sensitive indicator of contamination. In addition, fish is an important element in human diets, therefore, monitoring the concentrations of metallic contaminants in their meat is particularly important for food safety. This study aimed to assess the pollution of water ecosystems with selected toxic heavy metals in lakes Dratów, Czarne Sosnowickie, and Syczynskie. The concentration of Pb, Cd, and Hg in water, sediment, and freshwater fish muscle tissue was determined, and a food safety assessment was performed. The analysis of water and sediments showed that the sediments were characterised by a significantly higher concentration of heavy metals. Presumably, this ecosystem element plays an important role in the uptake of heavy metal contaminants by fish whose levels were higher in planktonophagous and benthophagous fish species as compared to predatory fish. The food safety assessment showed that amounts of heavy metals in the muscle tissue posed no threat to the health of consumers ingesting that fish species, neither individually (THQ) nor collectively (TTHQ).
ABSTRACT
The aim of the present study was to analyse the occurrence of macroscopically visible ovary alterations in 2 populations of northern pike Esox lucius L. originating from lakes in the Mazurian Lake District (NE Poland). The alterations were characterised by ovary tissue that was morphologically malformed, in part or in whole, and contained immature oocytes, i.e. trophoplastic or previtellogenic oocytes instead of vitellogenic oocytes. These alterations were found only in the ovaries, and no morphological alterations of the testes were noted. Macroscopic and histological analyses were carried out in order to classify the observed alterations in the ovaries. Three types of alterations were identified in which morphological malformations as well as histological investigation of the ovaries were considered. An analysis of the size and age of the fish in relation to the occurrence of alterations as well as of the macroscopic and histological nature of the alteration types was made. The data obtained revealed no lake or age dependency of the observed alterations. Based on the results obtained, we suggest that the presence of endocrine disruptors in the environment or/and genetic factors could be responsible for these kinds of gonad anomalies. However, our results did not allow us to determine the aetiology of the alterations.
