In Brief Zearalenone (ZEN) toxicity and its influences on animals have been described in the literature since the 1920s. This nonsteroidal, estrogenic mycotoxin is produced by species of fungi from the Fusarium genus and often found on field crops and other raw materials used in production of human food and both terrestrial and aquatic animal feed. Almost 100 years ago ZEN caught the eyes of the scientific community largely due to its estrogenic properties which are attributed to its molecular similarity to the female hormone estradiol (Figure 1). The consequences of these properties were observed in pathologies of farm animals. Later, it was also described in game and wild animals in their natural environments and in relation to pathologies in humans. In most aquaculture practices, a close contact between the natural aquatic environment and the cultured animals exist, for example sea cages, lake hapas and coastal pond systems, populated by fed fish.
In addition, studies revealed that ZEN can enter natural aquatic environments via pasture and agricultural run-off water. Moreover, the toxin was also found in water and sediment originating from aquaculture. Understanding this agricultural-ecotoxicological relationship is an important step in making aquaculture a sustainable and responsible industry. The Biomin Mycotoxin Survey has revealed that ZEN is present in 48% of the >200 samples of finished-compound aqua feed that were analyzed between 2016 and 2020 (Table 1 and Figure 3).