The toxicity of arsenic(III), chromium(VI) and zinc to groundwater copepods

Abstract

Groundwater ecosystems globally are threatened by anthropogenic contamination, yet there are few ecotoxicological data using obligate groundwater biota on which to base risk assessments. Copepods are found inhabiting aquifers of different geologies around the world and so are a useful taxon for use in ecotoxicological studies of groundwater. The aim of this study was to test the sensitivity of obligate groundwater copepods to metal contaminants (arsenic(III), chromium(VI) and zinc) in groundwater in static 96 h, 14 days and 28 days exposure tests. The copepods were variably sensitive to As, Cr and Zn, with Cr being the most toxic across all taxa. No taxon was consistently most sensitive and there was no apparent relationship between the hardness, pH and organic carbon concentration of the diluent water and the sensitivity of biota. As expected, toxicity increased with exposure period and we encourage the use of longer exposure periods in future toxicity tests with groundwater organisms to reflect the greater exposure periods likely to be associated with groundwater contamination.

The Toxicity and Uptake of As, Cr and Zn in a Stygobitic Syncarid (Syncarida: Bathynellidae)

“…The relatively high dissolved oxygen concentrations in the static tests is a likely consequence of the small test volume used and large surface area for gas exchange within the 24 well plates. Previous studies suggest that stygobitic crustaceans can survive well in oxygenated laboratory environments (e.g., [11,16]), and do not affect the toxic response of groundwater crustaceans to metals [30].…”

“…Table 1. Physicochemical variables and concentrations of common metals in the groundwater at the Somersby (NSW, Australia) collection sites (from [16]). In the laboratory, containers containing the invertebrates were placed in a dark environmental cabinet at 18 • C, which approximates the temperature of the groundwater at the time of collection.…”

“…Tests were conducted following the methods reported in Hose et al [16], which are summarised below. Once acclimated, the syncarids were removed from the collection container using a pipette and placed individually into wells of 24-well plates (Greiner) along with a known volume of clean groundwater from the collection site.…”

3D conservation planning: Including aquifer protection in freshwater plans refines priorities without much additional effort

“…The Hunter region is one of the few areas in Australia in which detailed studies of groundwater ecosystems have been undertaken (Hose, Janardhanan, Barron, & Pollino, 2015). A list of known taxa was compiled from available data sources (Asmyhr, 2013;Asmyhr & Cooper, 2012;Hancock & Boulton, 2008, 2009Hose, Janardhanan, et al, 2015;Hose, Symington, Lott, & Lategan, 2016;Korbel, Chariton, Stephenson, Greenfield, & Hose, 2017;Lategan, Torpy, Newby, Stephenson, & Hose, 2012). A basic typology of aquifers was established derived from the existing aquifer mapping and classification (DECCW, 2010).…”

Towards an integrated understanding of how micro scale processes shape groundwater ecosystem functions

“…There is no ultimate reason why groundwater metazoa might not use similar strategies, of course not in a free swim, but using unfavourable or even toxic zones briefly in search for food, and then recovering to more favourable zones. The few groundwater taxa used in ecotoxicological studies so far have proven to show a different pattern to that of their surface relatives (Avramov et al, 2013;Cifoni et al, 2017;Di Lorenzo et al, 2016;Hose et al, 2016;Mösslacher, 2000), being more sensitive towards stressors than their surface relatives, or less sensitive. Thus, metazoa very much depend on what is happening on the micro scale.…”