engleski

Age – releated acumulation of heavy metals in tissues of carp and catfish from Svitava lake (Bosnia and Herzegovina)

The purpose of our research was to verify accumulation of heavy metals (lead, mercury, cadmium and arsenic) in tissues of common carp (Cyprinus carpio) and catfish (Silurus glanis), frequently included in human diet. Ten fish of both sorts (5 individuals for each gender) were angled in the late summer of the year 2003 from Svitava Lake, Bosnia and Herzegovina. Fish age was determined by scales monitoring. Heavy metals were analyzed by atomic absorption spectrophotometry in organ samples (muscles, liver, kidneys and gonads). Carp and catfish mean age were 10.1 and 9.9 years, respectively, and no age difference was shown either between fish sorts or between genders. However, catfish displayed significantly greater mean body mass compared to carp (19.5 vs. 11.5 kg, P<0.05). All As concentrations were far below Maximal Admissible Concentration (MAC) in Croatia and other countries. All Hg concentrations were beyond 1 mg×kg-1, but most muscle samples of both sorts and all catfish liver samples were higher than 0.5 mg×kg-1 exceeding MAC value in many countries including Croatia, while Hg in gonads was under detection limit. Pb concentrations were higher than 1 mg×kg-1 (MAC in Croatia) in most muscle and even higher in all kidney samples, the values in catfish always being greater compared to carp ; most values in catfish liver also exceeded 1 mg×kg- 1. Cd concentration in all tissues apart from gonads were higher than 0.1 mg×kg-1 (MAC in Croatia). Greatest values were found in kidneys, followed by liver and muscles. The values in kidney were even higher than 1 mg×kg- 1 (MAC in Spain and USA), concentrations in catfish tissues always being greater compared to carp. Linear correlation between heavy metal concentration and age or body mass was shown for most tissues of both fish sorts, with exception of gonads. The correlation was proven for As in muscles of catfish and carp, as well as liver and kidneys of male carp. Also, the correlation was very strong for Hg in all carp and most catfish tissues of both genders. In carp, the correlation of Pb concentration with age and body mass could not be shown in male kidney tissue, while in male muscle tissue there was no correlation with body mass only. In female catfish no correlation of Pb concentration could be shown either with age or with body mass in any analyzed tissue, while in males the correlation was high in all tissues apart from gonads. The correlation of Cd concentration was high in carp tissues with exception of female kidneys ; in catfish, females displayed no correlation in muscle and liver, while in male kidneys correlation was proved only for both genders together. Our general conclusion is that heavy metals accumulate significantly in carp and catfish tissues, and that this process is species, sex and tissue specific.

Hg ; Pb ; Cd ; As ; carp (Cyprinus carpio) ; catfish (Silurus glanis) ; accumulation

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