Zearalenone contamination in rainbow trout farms in north-eastern Poland

Abstract

Zearalenone (ZEN) is a mycotoxin of potent estrogenic (hormone mimicking) activity in livestock animals, and it has frequently been found to be present in plant material worldwide, resulting in contamination of animal feed and food products. Recently, ZEN has also been reported in soil, drainage water, wastewater effluents, and rivers. However, the problem with ZEN in aquaculture remains relatively unexamined up to now. Here, we present the concentrations of ZEN in selected organs of rainbow trout (part of the dorsal white muscles with skin, the ovary, the liver and gallbladder, and the caudal part of the intestine with its content) that were purchased from three commercial fish farms in north-eastern Poland. ZEN was not detected in the trouts' muscles, and in the liver and the intestines only trace amounts of the mycotoxin were found (<2.0μg·kg−1). Interestingly, the highest concentrations of ZEN were found in the fish's ovaries (up to 7.1μg·kg−1). Additional analyses of system (surface) water and fish feed samples from the farms indicate that animal feed may be a possible source of ZEN contamination (concentration up to 81.8μg·kg−1). These results suggest that ZEN contamination may pose little health risk (if any) to the consumers of the fish. However, accumulation of this mycotoxin in the ovaries may be a concern for the aquaculture industry. Further research should evaluate the scale of this problem and answer whether the concentrations of ZEN found in feed affect fish production, especially reproduction.