Novel Protocol for Acute In Situ Ecotoxicity Test Using Native Crustaceans Applied to Groundwater Ecosystems

Andrea Castaño-Sánchez,Ana Sofia P S Reboleira,Florian Malard,Gabriela Kalčíková

doi:10.3390/w13081132

Abstract

Current standardized laboratory test protocols use model species that have limitations to accurately assess native species responses to stressors. We developed and tested a novel acute in situ protocol for testing field-collected organisms. We used Asellus aquaticus and NaCl as a reference toxicant to test for the effects of location (laboratory vs. in situ), medium (synthetic vs. field water), substrate (presence vs. absence), and protocol replicability. We further tested the protocol using groundwater-adapted isopods: Proasellus assaforensis for the effect of location, P. cavaticus of medium and P.lusitanicus of substrate. Our results showed that A.aquaticus’ lethality obtained with the novel acute in situ protocol did not significantly differ from those from laboratory testing. However, laboratory tested P.assaforensis showed a higher sensitivity, suggesting that its acclimation to laboratory conditions might have pernicious effects. A. aquaticus and P. cavaticus showed a higher mortality using synthetic medium in situ and under laboratory conditions, which overestimated the stressor’s effect. Besides, substrate use had no significant effect. The novel acute in situ protocol allows the use of native species under realistic scenarios. It is particularly well adapted for assessing the risk of groundwater ecosystems but it can be applied to a wide range of ecosystems.

Highlights

Ecotoxicological approaches are indispensable tools in environmental risk assessment (ERA)
For A. aquaticus, we found no significant differences in LC50 between in situ and lab experimental setups under the same conditions including comparison across the two replicates (Figures 2 and 3, Tables S5a and S6a)
The effect of substrate tested in the first replicate experiment with A. aquaticus did not provide any significant differences on salinity sensitivity under the same experimental setups (Figure 3, Table S5c)

Summary

Introduction

Ecotoxicological approaches are indispensable tools in environmental risk assessment (ERA). The sensitivity to anthropogenic stressors varies markedly among species, and environmental variability, together with food web structure, plays an important role in determining the organisms’ response [2,3]. Acute tests are well replicated and cost-effective tools, which are a reliable and essential support for ERA and decision making [4]. The use of acute tests has yielded a massive amount of ecotoxicological data, compiled and available in international databases (e.g., [5]). Despite the incremental complexity of ecotoxicological studies and the encouragement of ERA guidelines to use long-term studies [6], acute toxicity tests have remained an important source of data for species distributions models [5,7,8,9,10]

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Results

Discussion

Conclusion