Daphnia survival decreased as the concentration of Cyanobacterial neurotoxin BMAA increased

Cyanobacteria, blue-green algae, produces and releases cyanotoxins during Harmful Algal Blooms (HABs) that cause ecological, economic, and human and pet health concerns. The majority of cyanobacteria produce the neurotoxin beta-N-Methylamino-L-alanine (BMAA). Human exposure to BMAA may be an environmental cause of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Parkinson’s disease, and Alzheimer’s disease. The effect of BMAA on zooplankton has not been studied in depth. We investigated how ingestion of BMAA affects the reproductive and developmental behavior of Daphnia in the short- and long term. We hypothesized that different concentrations of BMAA will affect the behavior of Daphnia associated with development and reproduction. We predicted that Daphnia would grow slower and produce fewer offspring in higher concentrations of BMAA. Daphnia were exposed to BMAA concentrations (0, 1, 10, 50, 100, 200 and 300 g/L) for 96 hours at 22-240C with a 16:8 light-dark cycle. The number of survivors and the body length of Daphnia was measured at the end of the experiment. The data were analyzed using One way ANOVA, Kruskal-Wallis, and pairwise comparisons in SYSTAT 13. Results indicated that Daphnia survivorship declined as the concentration of BMAA increased and larger Daphnia had greater survival. The hypothesis was partially supported as Daphnia had lower survival in higher concentrations of BMAA. Our next step is to analyze long-term exposure data to fully test the hypothesis. More studies are needed to better understand the mechanism by which BMAA affects Daphnia development and reproduction.https://digitalcommons.snc.edu/collaborative_presentations/1008/thumbnail.jp