Environmental pollution | 2019
Usability of the bivalves Dreissena polymorpha and Anodonta anatina for a biosurvey of the neurotoxin BMAA in freshwater ecosystems.
Abstract
The environmental neurotoxin β-methylamino-L-alanine (BMAA) may represent a risk for human health in case of chronic exposure or after short-term exposure during embryo development. BMAA accumulates in freshwater and marine organisms consumed by humans. It is produced by marine and freshwater phytoplankton species, but the range of producers remains unknown. Therefore, analysing the phytoplankton composition is not sufficient to inform about the risk of freshwater contamination by BMAA. Filter-feeders mussels have accumulation capacities and therefore appear to be relevant to monitor various pollutants in aquatic ecosystems. We investigated the suitability of the freshwater mussels Dreissena polymorpha and Anodonta anatina for monitoring BMAA in water. Both species were exposed to 1, 10, and 50\xa0μg of dissolved BMAA/L daily for 21 days, followed by 42 days of depuration in clean water. On days 0, 1, 7, 14, and 21 of exposure and 1, 7, 14, 21 and 42 of depuration, whole D.\xa0polymorpha and digestive glands of A.\xa0anatina were sampled, and the total BMAA concentration was measured. D.\xa0polymorpha accumulated BMAA earlier (from day 1\xa0at all concentrations) and at higher tissue concentrations than A.\xa0anatina, which accumulated BMAA from day 14 when exposed to 10\xa0μg BMAA/L and from day 7 when exposed to 50\xa0μg BMAA/L. As BMAA accumulation by D.\xa0polymorpha was time and concentration-dependent, with a significant elimination during the depuration period, this species may be able to reflect the levels and dynamics of water contamination by dissolved BMAA. The species A.\xa0anatina could be used for monitoring water concentrations above 10\xa0μg BMAA/L.