Brine shrimp Artemia salina to evaluate the impact of environmental concentrations of BMAA and isomers, DAB and AEG, via mortality (nauplii) and behavioural (adult) tests

BMAA and its isomers, DAB and AEG, are toxins mainly produced by cyanobacterial blooms and represent an emerging risk worldwide. Anthropization and climate changes are expanding blooms and the presence of these toxins has been evidenced in different environments including water and air. Investigated since decades, BMAA is a recognized danger in cases of bioaccumulation or when directly exposed to relatively high doses (μg/L). However, little is known about its isomers, DAB and AEG, and in general about toxicity at environmental doses (ng/L). With the present study we investigated the effect of environmental concentrations of BMAA, AEG and DAB on a model representative of aquatic organisms, the crustacean Artemia salina. Toxicological effects of these molecules were tested at two different developmental stages. Mortality experiments were developed on artemia nauplii while behavioural tests were performed on adult artemia. BMAA was evidenced as the most toxic compound in mortality essays showing a statistically significant impact already after 24 h of exposure. DAB and AEG reached a statistically significant effect only following 48 h of exposure, a result that was of reduced intensity when compared to BMAA. Furthermore, all tested molecules altered the behavioural tests performed on adult artemia 1 h after exposure. Male artemia demonstrated to be more impacted than females thus suggesting possible sex differences in the involved toxicological pathways.