The effect of growth and physical condition on the level of heavy metals accumulated in the organs of common bream (Abramis brama L.) populating Lake Balaton was investigated on samples collected in October 1999 and May 2000 from two well-separable sites regarding their trophic state and pollution impact (western and eastern basins). The average metal concentrations in the organs of fish varied in the following ranges: Cd, 0.39-1.98; Cu, 1.73-57.3; Hg, 0.02-0.13; Pb, 0.39-3.15; and Zn, 12.7-159.3 microg/g dry weight. The highest Cd, Cu, Pb and Zn concentrations were detected in the gill and liver of fish, whereas the highest Hg concentrations were measured in the muscle. The maximum metal concentrations in the muscle of bream were on average below the maximum permissible levels for human consumption. Significant positive correlation was found among the heavy metal load of bream and their instantaneous growth rate; hardly any connection was observed related to the physical condition of samples. The relatively low metal concentrations of the ambient water and their poor correlation with the heavy metal load of bream, indicates that for the mature stages of this fish species the metal uptake from food is predominant, and thus the heavy metal load of fish reflect more the pollution state of the sediment and its biota, rather than that of the ambient water.
The concentration of heavy metals (cadmium, copper, lead, mercury and zinc) found in muscle, gills and liver of eel, bream and pike-perch living in Lake Balaton (Hungary) varied significantly between fish species and organs. The toxic metals in the muscle of fish, except for cadmium in bream, were below the maximum permissible level for human consumption. Cadmium concentrations above the maximum permissible level occurred in autumn in a few small individuals of bream, which, because they have poor culinary value and are seldom consumed, does not represent a risk for humans. Cadmium, copper, lead and zinc levels proved to be higher in eel and bream compared to pike-perch, while high mercury concentrations were found in the predator fish, pike-perch. Mercury accumulated most in the muscle in each species, while other metals were found in higher levels in the gills and liver. Seasonal differences were found for cadmium in each species and for lead in eel; the concentrations being elevated in autumn compared to spring. The fish species studied as bio-monitors demonstrated that the overall heavy metal pollution of Lake Balaton is not significant, although, during summer an increase of cadmium and lead loading could occur at the catchment area and in the lake. Studies on the size (age) dependency of heavy metal concentrations showed that, in most cases, none or a negative relationship exists for each organ and metal in all species studied, and a positive regression coefficient was characteristic only on some occasions for mercury, cadmium and lead.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.