Microalgae are at the basis of aquatic food webs and may be the indirect target of herbicides from agricultural and urban uses. They also interact with other compounds from their environment such as natural dissolved organic matter (DOM), which can itself interact with herbicides. This thesis aimed to study, in laboratory controlled conditions, the influence of natural DOM on herbicide toxicity to microalgae by using monospecific, non-axenic cultures. The experiments included: natural freshwater and marine DOM, three herbicides (irgarol, diuron and S-metolachlor) singly and in mixtures, two freshwater microalgae (Gomphonema gracile and Sphaerellopsis sp.) and two marine microalgae (Chaetoceros calcitrans and Tetraselmis suecica). Effects were evaluated on... |