Can Winter Road De-Icing Affect Mortality of Organisms in Aquatic Ecosystems? An Experimental Approach

Magdalena Frąk,Piotr Bednarczyk

doi:10.3390/w13182524

Abstract

Road maintenance in winter using de-icing agents, which is widely used in Eastern Europe, is the cause of water salinization in neighbouring environments, which might lead to biodiversity loss in aquatic ecosystems. In this study, we investigated NaCl toxicity to test young organisms: Daphnia magna and Poecilla reticulata (standard tests organisms). The salinity of NaCl was measured by electrolytic conductivity (EC). It was statistically demonstrated that the test solutions should be prepared using natural water. For D. magna the NOEC was 7.17 mS/cm and the LC50 9.76 mS/cm. Poecilla reticulata showed resistance to salinity up to a conductivity of 25.2 mS/cm, and no lethal effects were recorded for any individual in the test population. The study showed that winter salinities recorded in inland waters (without emergencies such as sudden influx of pollutants due to industrial accidents) are unlikely to affect fish but may be hazardous to small plankton. However, the high dare of D. magna may result in a reduction of planktivorous fish.

Highlights

According to Schuytema et al [11], the salinity corresponding to the sodium chloride toxicity value for half of the Daphnia magna test population is 8.38 mS/cm on average, so this value was considered as a reference in subsequent tests
The results presented here do not allow to verify whether the mortality of Daphnia magna is caused by salinity, whose concentration exceeds the adaptive capacity of this species, or whether the mortality is caused by the high osmotic pressure of the solution
The paper shows that winter road de-icing does not necessarily affect the mortality cope with the average salinity of inland waters

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Its use is associated with negative environmental effects, as it is dissolved in the melting snow and ice and subsequently flushed by overland flow reaching reservoirs and lakes It affects groundwater and soils near traffic routes. We assessed the sensitivity of Daphnia magna and Poecilla reticulata to salinity levels as a basis to determine whether salinization of water resulting from saline inflows from traffic routes can be hazardous to aquatic biotopes. These test species can act as excellent model organisms to study the effect of salinity on aquatic biota because of their well-recognized sensitivity to environmental changes and the fact they are ubiquitous in freshwater systems [8,9]. At a time of climate change and rapidly varying habitat conditions, it is critical to determine their potential impact on biodiversity and ecological structure

Materials and Methods

Results and Discussion

Comparative

Conclusions