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'.

Keywords: ecosystem functions; ecosystem services; freshwater degradation; global change; human health.

Figure 1.

Monitoring and protecting fresh waters from continued salinization using scientific evidence from experiments and models and a triple-bottom-line (TBL) approach with public outreach programmes to develop comprehensive regulations and advanced management strategies. The consequences of management strategies and regulatory actions should be evaluated and used to inform monitoring programmes and reassess models that calculate the social, environmental, and economic costs and benefits.

Figure 2.

A threshold based model for monitoring, regulatory action, and management given the extent of salinization in a freshwater ecosystem, adapted from Liu et al. [77]. (A) Monitoring and modelling the economic, social, and environmental costs of salinization before environmental consequences occur. (B) Regulatory action and management can protect ecosystem function and ecosystem services while the effects of salinization are still reversible (yellow shaded area). (C) Extensive management can help mitigate some harmful ecological and economic effects. However, the overall effects are probably irreversible (red shaded area), and the economic and social costs are extensive (D), unless partnerships and cooperative agreements are reached among stakeholders to manage salinization (E).