Ondine THOUARD

Cyanobacteria proliferations may induce ecological, health and socioeconomic major issues. Cyanobacteria, photosynthetic organisms, are a natural component of phytoplankton or phytobenthic communities. However, some chemicophysical (eg. nutrients, flow) and climatical (photoperiod, temperature) parameters enhance cyanobacterial growth, allowing them to dominate phytoplankton communities forming blooms (=proliferations). Among more than 3,000 cyanobacteria species, some of them produce cyanotoxins (microcystins, anatoxins, saxitoxins, cylindrospermopsins), which are environmental and human health threats, and emerging cyanopeptids (aeruginosins, microcyclamids, etc…) for which the toxicity is not well understood nowadays. Additional to cyanobacterial ecological and health impact, cyanotoxins water concentrations are controlled by ANSES (French Agency for Food Health Security), sometimes causing bathing lake area closures, also impacting socioeconomic activities. 

My PhD is included on the ‘CYANORISK’ project and is focused on Champardennais recreational areas. The aim of this work is to 1/ identify main sources and stocks of nutrients (nitrogen, phosphorus), responsible for cyanobacterial blooms, 2/ understand cyanotoxin and emerging cyanopeptid ecodynamics in freshwater by measuring their contents in water and biota and 3/ characterize health risk due to contaminated fish consumption during blooms.