Reduced genetic diversity of freshwater amphipods in rivers with increased levels of anthropogenic organic micropollutants

Abstract

Anthropogenic chemicals in freshwater environments contribute majorly to ecosystem degradation and biodiversity decline. In particular anthropogenic organic micropollutants (AOM), a diverse group of compounds, including pesticides, pharmaceuticals, and industrial chemicals, can significantly impact freshwater organisms. AOM were found to impact genetic diversity of freshwater species; however, to which degree AOM cause changes in population genetic structure and allelic richness of freshwater macroinvertebrates remains poorly understood. Here, the impact of AOM on genetic diversity of the common amphipod Gammarus pulex (Linnaeus, 1758) (clade E) was investigated on a regional scale. The site‐specific AOM levels and their toxic potentials were determined in water and G. pulex tissue sample extracts for 34 sites along six rivers in central Germany impacted by wastewater effluents and agricultural run‐off. Population genetic parameters were determined for G. pulex from the sampling sites by genotyping 16 microsatellite loci. Genetic differentiation among G. pulex from the studied rivers was found to be associated with geographic distance between sites and to differences in site‐specific concentrations of AOM. The genetic diversity parameters of G. pulex were found to be related to the site‐specific AOM levels. Allelic richness was significantly negatively correlated with levels of AOM in G. pulex tissue (p < 0.003) and was reduced by up to 22% at sites with increased levels of AOM, despite a positive relationship of allelic richness and the presence of waste‐water effluent. In addition, the inbreeding coefficient of G. pulex from sites with toxic AOM levels was up to 2.5 times higher than that of G. pulex from more pristine sites. These results indicate that AOM levels commonly found in European rivers significantly contribute to changes in the genetic diversity of an ecologically relevant indicator species.

Limited genetic variability and spatial population structure in grasshoppers between natural and metal-contaminated areas in Egypt

“…Various forms of pollution can significantly alter the genetic composition of populations and influence genetic variation through 4 primary mechanisms: (i) increased mutation rates; (ii) directional selection favoring tolerant genotypes; (iii) genetic bottlenecks; and (iv) altered migration patterns ( Mussali-Galante et al 2014 ). Numerous studies have examined contaminant exposure effects on the genetics of both terrestrial ( Grzywacz et al 2012 , Giska et al 2015 , Renault et al 2023 ) and aquatic ( Gouin et al 2019 , 2023 , Švara et al 2022 ) populations. In addition to toxicants, natural phenomena like mutations, selection, stochastic processes, and migration can modify the genetic variability of populations ( Mussali-Galante et al 2014 ).…”

Optimizing laboratory cultures of Gammarus fossarum (Crustacea: Amphipoda) as a study organism in environmental sciences and ecotoxicology

“…Further, many species are directly affected and adjust their feeding behaviour in response to changes in the composition of their food source (leaf litter), with cascading effects on the aquatic food web (van Riel et al, 2006;Woodward et al, 2008;Little et al, 2020). Finally, amphipods are sensitive to a wide range of toxicants, and are thus commonly used by stakeholders and ecotoxicologists for field and laboratory based studies (McCahon and Pascoe, 1988;Felten et al, 2008;Bundschuh and Schulz, 2011;Feckler et al, 2012Feckler et al, , 2014Kosfeld et al, 2020;Fu et al, 2020;Rothe et al, 2022;Švara et al, 2022).…”

“…However, for Europe and adjacent regions there is a major discrepancy between field assays, which are commonly performed on a range of (native) species, especially of the genus Gammarus (e.g., Bundschuh et al, 2013;Feckler et al, 2014;Eisenring et al, 2016;Burdon et al, 2019;Arlos et al, 2020;Lauper et al, 2022;Švara et al, 2022), and laboratory-based studies, which are most commonly performed on the non-native model organism Hyalella azteca (Saussure, 1858) (e.g., Borgmann et al, 2005;Cothran et al, 2013;James and McClintock, 2017;Kosfeld et al, 2020;Fu et al, 2020). The latter is easy to maintain in the lab, as is common for other model organisms such as Daphnia magna Straus, 1820, Caenorhabditis elegans (Maupas, 1900) or Danio rerio (F.Hamilton, 1822), yet may not be necessarily representative of amphipods inhabiting small tributary streams, which are commonly affected by environmental pollutants (e.g., Munz et al, 2017).…”

“…Consequently, they are frequently used in toxicity tests (Geffard et al, 2010). Neither of these species has been easily cultivated (but see Pöckl, 1995), and thus most past studies and assessments of chemical compounds relied purely on wild-caught individuals (e.g., McCahon and Pascoe, 1988;Bundschuh et al, 2013;Mehennaoui et al, 2016;Arambourou et al, 2017;Straub et al, 2017;Lauper et al, 2022;Švara et al, 2022) or again on more tolerant model organism such as H. azteca, representing a species complex native only to North and Central America (e.g., Wang et al, 2004;Borgmann et al, 2005;Fu et al, 2020). This is problematic for two reasons.…”