Effects of global change on the ability of stream biofilm to dissipate the herbicide glyphosate.

The herbicide glyphosate is contaminating a large number of freshwater ecosystems worldwide and its fate and effects remains uncertain in light of the effects of global change. The present study examines how variations in water temperature and light availability relative to global change affect the ability of stream biofilms to degrade the herbicide glyphosate. Biofilms were exposed in microcosms to two levels of water temperature simulating global warming (Ambient = 19-22 °C and Warm = 21-24 °C) and three levels of light representative of riparian habitat destruction due to land use change (Dark = 0, Intermediate = 600, High = 1200 μmol photons m s).