Study finds human-induced salinization is a major threat to freshwater ecosystems

A recent study published in the Proceedings of the National Academy of Sciences (PNAS) found that human-induced salinization caused by the use of road deicing salts, agricultural practices, mining operations, and climate change is a major threat to the biodiversity and functioning of freshwater ecosystems. According to the study, current water guidelines do not protect freshwater ecosystems from salinization. https://www.pnas.org/doi/full/10.1073/pnas.2115033119

Results of the study indicated that salinization will cause substantial zooplankton mortality. The loss of zooplankton triggered a cascading effect causing an increase in phytoplankton biomass at 47% of study sites. Such changes in lake food webs could alter nutrient cycling and water clarity and trigger declines in fish production.

We depend on freshwater ecosystems for our drinking water. The Great Lakes on the Canada-U.S. border provide drinking water for more than 40 million Americans. According to William Hintz, an assistant professor in the University of Toledo’s Department of Environmental, who conducted the study, “Once salts get into our freshwater supplies, it is difficult or in some cases impossible to get salt out, and high salt concentrations can persist for decades.”

Hintz says, “Policymakers will need to craft environmental legislation that lowers the allowable chloride concentrations in many regions to protect freshwater ecosystems,” Hintz says. De-icing salts significantly reduce car accidents and injuries, so we can’t just give them up overnight. Hintz stresses that if we better understand the sources of salt contamination, we can, in turn, work to protect freshwater lakes from salinization. According to Hints, “This may require better environmental monitoring by scientists, and regulations aimed at reducing salt pollution from multiple human-caused sources.”

Additional source: https://www.inverse.com/science/america-road-salt-hurting-ecosystems-drinking-water