engleski

Comparison of metal accumulation efficiency in acanthocephalans, gammarids and fish under the impact of municipal and technological wastewaters

In addition to chemical water analysis, assessment of biologically available pollutants involves application of bioindicators, mostly presented by fish, crustaceans and bivalves. Regarding metal exposure, fish intestinal parasites acanthocephalans were suggested as promising bioindicators, since it was reported that metal accumulation was higher in acanthocephalans compared to the other bioindicator organisms. Thus, the aim of the present study was to compare spatial and seasonal metal accumulation efficiency in acanthocephalans (Dentitruncus truttae Sinzar, 1955) and commonly used bioindicators, fish brown trout (Salmo trutta Linnaeus, 1758) and gammarids (Gammarus balcanicus Koch, 1836). Metal exposure was evaluated in the wastewater impacted Krka River (polluted site) and in the river source (reference site) in autumn (2015) and spring (2016). Metals were measured by high resolution inductively coupled plasma-mass spectrometry in fish intestine, whole gammarids and acanthocephalans, which were wet digested in a drying oven at 85°C for 3.5 hours using concentrated HNO3 and H2O2. The highest levels of Zn>Fe>Rb were found in fish, Sr>Fe>Zn in gammarids and Zn>Fe>Cu in parasites. In moderately polluted Krka River, acanthocephalans showed higher metal accumulation efficiency than fish and gammarids for Cd, Mn, Pb, Tl, while lower for Cs, Fe, Rb. Bioconcentration factors indicated 4-55 times higher metal levels (Cd>Tl>Pb>Sr>Cu>Ca>Mn) in parasites compared to fish and 3-22 times (Tl>Cd>Pb>Mn) compared to gammarids. Spatial differences were evident in both seasons and in all organisms as higher Co, Fe and Mn at polluted and Cd and Tl at reference site. Consequently, further investigation on sediment and dietary metal sources are needed.

brown trout ; parasites ; amphipoda, metals

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