Regulations are needed to protect freshwater ecosystems from salinization

Abstract

Anthropogenic activities such as mining, agriculture and industrial wastes have increased the rate of salinization of freshwater ecosystems around the world. Despite the known and probable consequences of freshwater salinization, few consequential regulatory standards and management procedures exist. Current regulations are generally inadequate because they are regionally inconsistent, lack legal consequences and have few ion-specific standards. The lack of ion-specific standards is problematic, because each anthropogenic source of freshwater salinization is associated with a distinct set of ions that can present unique social and economic costs. Additionally, the environmental and toxicological consequences of freshwater salinization are often dependent on the occurrence, concentration and ratios of specific ions. Therefore, to protect fresh waters from continued salinization, discrete, ion-specific management and regulatory strategies should be considered for each source of freshwater salinization, using data from standardized, ion-specific monitoring practices. To develop comprehensive monitoring, regulatory, and management guidelines, we recommend the use of co-adaptive, multi-stakeholder approaches that balance environmental, social, and economic costs and benefits associated with freshwater salinization. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.

A review of the species, community, and ecosystem impacts of road salt salinisation in fresh waters

“…professionals, and the public (Schuler et al, 2019). Attention to road salt salinisation is growing because of the high concentrations observed in the environment, lasting ecological effects, and contamination of our drinking water (Fay & Shi, 2012;Findlay & Kelly, 2011;Tiwari & Rachlin, 2018).…”

“…Given that the most commonly used road deicer by far is NaCl (Evans & Frick, 2001) and the paucity of information on the ecological effects of alternatives such as MgCl 2 and CaCl 2 , the impacts of NaCl is the primary focus of our review. Chloride is generally one of the most definitive indicators of road salt pollution (Schuler et al, 2019). Some field or laboratory studies on road salt report conductivity, rather than Cl⁻ concentration.…”

Concurrent improvement and deterioration of epilimnetic water quality in an oligotrophic lake over 37 years

“…Further, road salts can increase the concentrations of heavy metals and nutrients in lakes from peripheral habitats (Kaushal et al ; Schuler and Relyea ). Thus, proactive policy and environmental management on the whole‐catchment scale will be needed to protect our freshwater lakes from salinization (Schuler et al ).…”

Bridging the Information Gap Between Science and Society: A Solution to Nonpoint Source Contamination?

“…Within the United States, the Environmental Protection Agency (EPA) has established water quality criteria for chloride concentrations in freshwater (acute: 860 mg/L, chronic: 230 mg/L) as a first step in regulating road de‐icing salt contamination (USEPA 1988). As the frequency of de‐icing salt application is directly linked to snowfall, these water quality criteria are likely difficult to enforce at the application level and fail to incorporate the ion‐specific toxicity often associated with freshwater salinization (Hintz and Relyea 2017; Schuler et al 2019). Therefore, realistic solutions for preventing chloride concentrations from exceeding the established thresholds would need to involve: 1) changes in the road salt formulations themselves (nontoxic de‐icing agents), 2) the implementation of ion‐specific regulatory standards (Schuler et al 2019), or 3) suggestions for best management practices that are cost‐efficient for tight‐budgeted municipalities.…”

“…This type of pollution can contribute to a “tragedy of the commons” disrupting the recreational, commercial, and economic value of natural spaces (Kaushal et al 2018). Unfortunately, many regulatory standards or metrics (e.g., water quality criteria, total maximum daily loads, best management practices) are difficult to apply and lack the nuance required to generate effective solutions (Cabe and Herriges 1992; Craig and Roberts 2015; Schuler et al 2019). Applicable solutions to nonpoint source pollution, therefore, may be advanced through product innovation at the development stage: replacing harmful products with legitimate “eco‐friendly” alternatives can empower consumers to take personal responsibility for their ecological footprint (Wachinger et al 2013; Dangelico 2016).…”