Occurrence of mycotoxins in commercial aquafeeds in Asia and Europe: a real risk to aquaculture?

There is increasing awareness of the negative effects of mycotoxins in aquatic species, which is highlighted in recent publications. Partly due to climate change associated with an overall increase of mycotoxins contamination in plant ingredients, and also due to the tendency to replace expensive animal-derived proteins, such as fish meal, by more economical plant proteins sources, which increases the probability of mycotoxin contamination in aquaculture feeds (Hooft etal. ). Over a 1-year period, 41 samples of finished aquaculture feed, both shrimp and fish, were analysed within the scope of BIOMIN mycotoxin survey programme. The samples were tested for aflatoxins, zearalenone, deoxynivalenol, fumonisins and ochratoxin A. Samples were sourced in Asia (31 samples) and Europe (10 samples) from fish/shrimp farms or feed producers. The values detected pose a risk for several important aquaculture species, assuming single mycotoxin contamination, that is excluding possible additive and synergetic effects between mycotoxins. Co-occurrence of mycotoxins in feeds may induce synergistic effects and increase the negative impact of mycotoxins in aquatic-farmed species at lower levels than when present in single contamination. This review gives an overview of the different mycotoxins and revises the effects of mycotoxins in aquatic species. Additionally, it reports the levels of mycotoxins in aquafeeds in 2014 and compares detected levels with possible negative effects in fish and shrimp. As it is highlighted by the results of the survey, the risk of co-occurrence is high and the knowledge on the effects of multimycotoxins contamination in aquatic species is basically none.