Most lakes continuously release nitrogen into the atmosphere

In a process that may help lakes maintain healthy levels of nutrients, new research from the University of Minnesota College of Biological Sciences shows that a majority of the lakes examined are continuously shedding nitrogen into the atmosphere. Nitrogen, along with phosphorus, is a nutrient that can be found in excess in some lakes. This excess can cause algal blooms that can overwhelm a lake and also produce toxins that can harm fish, local wildlife and people that use water from lakes. In the research published in the Proceedings of the National Academy of Sciences , scientists set out to examine if lakes were gaining nitrogen from or losing nitrogen to the atmosphere. They examined the saturation of gaseous nitrogen in 34 lakes in the Upper Midwest of the United States. Researchers found approximately 86% of the 247 water column samples from lakes were supersaturated with gaseous nitrogen. These findings suggest: the loss of gaseous nitrogen in the lakes is not adequately offset by nitrogen fixation, the process by which nitrogen changes from a gas into compounds such as nitrate or ammonium; and "Basically, lakes are constantly leaking nitrogen back into the atmosphere," said Bri Loeks-Johnson, a graduate student who worked on the study through Professor Jim Cotner's laboratory.