The use of neonicotinoid insecticides are thought to affect not just bees, but also freshwater aquatic life, according to a study. Constant exposure to even low amounts of these insecticides is enough to have lethal effects on freshwater animals, the study explains.
The study, published in the journal PLOS ONE, shows that at least one of the insecticides of this class may have toxic and lethal effects on invertebrates living in freshwater sources.
The study made use of freshwater shrimp who were continuously exposed to pulsed high and low concentrations of imidacloprid, an insecticide belonging to the neonicotinoid class. These insecticides reached water sources via runoff during rain, making up the peak sources of exposure.
This exposure, carried out for not more than a day, had less harmful effects on the marine life in the freshwater source, and they recovered rapidly after getting exposed to clean water. Constant exposure, on the other hand, led to starvation among these organisms, and finally death within a couple of weeks.
The reason behind this 'starvation' is thought to be the result of an impaired feeding behavior as a result of neurotoxicity arising due to exposure to these insecticides.
Also, the study confirmed that seasonal and environmental factors played an important role in modifying the final results of the study, as the organism's lipid reserves and its fitness do change the effects of its exposure to the insecticides.
To eliminate these effects, the researchers are currently working on a new mathematical model which may help predict harmful concentrations and exposure times.