Gammarus fossarum as a sensitive tool to reveal residual toxicity of treated wastewater effluents

Abstract

Wastewater treatment plants (WWTPs) are one of the main sources of freshwater pollution eventually resulting in adverse effects in aquatic organisms. Treated effluents can contain many micropollutants at concentrations often below the limit of chemical quantification. On a regulatory basis, WWTP effluents have to be non-toxic to the aquatic environment, wherefore not only chemical abatement but also ecotoxicological evaluation through relevant bioassays is required. Standardized bioassays currently used are often not sensitive enough to reveal a residual toxicity in treated effluents. Therefore, attention must be paid to the development of better-adapted approaches implementing more sensitive organisms and relevant endpoints. In this study, the toxicity of two differently treated effluents (activated sludge treated effluents with and without ozonation) towards the ecologically relevant species Gammarus fossarum was evaluated. Organism fitness traits such as reproduction and sperm DNA integrity were followed in exposed organisms. In complement, enzymatic biomarkers were measured indicating the presence of neurotoxic compounds (acetylcholinesterase activity), the presence of pathogens likely to increase the toxic effects of chemical compounds (phenol-oxidase activity), and the presence of toxic compounds inducing detoxification mechanisms (glutathione-S-transferase activity). Enzymatic activities were not modified, but significant sub-lethal effects were observed in exposed organisms. In both effluents, females showed a retarded molt cycle, a reduced fecundity and fertility, and >90% of developed embryos exhibited developmental malformations. In addition, a slight but significant genotoxic effect was measured in gammarid sperm. In a whole, no difference in toxicity was found between both effluents. Coupling reproduction impairment and genotoxicity assessment in Gammarus fossarum seems to be a valuable and sensitive tool to reveal residual toxicity in effluents containing a mixture of micropollutants at very low concentrations. Finally, a direct relationship between the observed toxic responses and the quantified micropollutant concentrations could not be evidenced.

Detection of chemically induced ecotoxicological effects in rivers of the Nidda catchment (Hessen, Germany) and development of an ecotoxicological, Water Framework Directive–compliant assessment system

“…Gammarus fossarum was chosen as test species, even though it is not yet a standard organism in ecotoxicological testing, because of its wide distribution, high abundance, its sensitivity towards chemicals such as micropollutants from wastewaters and pesticides [16,[28][29][30] and since it has already been used for in situ testing of environmental conditions [20,28,31,32]. As G. fossarum feeds on detritus, leaves and other organic materials, it provides an important ecosystem service as shredder and serves as food for fish.…”

Poison in paradise: increase of toxic effects in restored sections of two rivers jeopardizes the success of hydromorphological restoration measures

“…The genus Gammarus, which includes the freshwater amphipod Gammarus fossarum, reacts sensitively to pollutants such as pesticides (e.g., terbutryn, fenoxycarb) or micropollutants from wastewater (e.g., 17α-ethinylestradiol) [49][50][51][52][53][54][55]. Furthermore, G. fossarum has already been used in field studies to assess the conditions of rivers and environmental samples [56][57][58][59][60]. The gammarids used in the present study were collected 1 day prior to the active biomonitoring campaigns and laboratory experiments from the source region of the river Nidder (N 50°29′7″, E 9°14′52″, Sichenhausen, Hessen, Germany), and kept in aerated river water in a climate chamber at 10 ± 1.5 °C over-night until tests started.…”

Shotgun lipidomics and mass spectrometry imaging unveil diversity and dynamics in Gammarus fossarum lipid composition

“…Freshwater sentinel species Gammarus fossarum is one of the most represented amphipod crustaceans widespread across European inland aquatic habitats (Wattier, et al, 2020). Its broad distribution and sensitivity to a wide range of contaminants has made this keystone species a valuable model organism in ecotoxicology (Besse, et al, 2013;Chaumot, et al, 2015;Dedourge-Geffard, et al, 2009;Kunz, et al, 2010;Mehennaoui, et al, 2016;Wigh, et al, 2017). Endocrine effects (e.g., accelerated oocyte maturation, smaller vitellogenic oocytes, and decreased spermatozoon production) have also been observed in this species when exposed to endocrine disrupting chemicals in wastewater effluents (Schirling, et al, 2005;Trapp, et al, 2015) and in laboratory experiments (Schirling, et al, 2005;Trapp, et al, 2015).…”