Natural variability of biochemical biomarkers in the macro‐zoobenthos: Dependence on life stage and environmental factors

Abstract

Biomarkers are widely used in ecotoxicology as indicators of exposure to toxicants. However, their ability to provide ecologically relevant information remains controversial. One of the major problems is understanding whether the measured responses are determined by stress factors or lie within the natural variability range. In a previous work, the natural variability of enzymatic levels in invertebrates sampled in pristine rivers was proven to be relevant across both space and time. In the present study, the experimental design was improved by considering different life stages of the selected taxa and by measuring more environmental parameters. The experimental design considered sampling sites in 2 different rivers, 8 sampling dates covering the whole seasonal cycle, 4 species from 3 different taxonomic groups (Plecoptera, Perla grandis; Ephemeroptera, Baetis alpinus and Epeorus alpicula; Tricoptera, Hydropsyche pellucidula), different life stages for each species, and 4 enzymes (acetylcholinesterase, glutathione S-transferase, alkaline phosphatase, and catalase). Biomarker levels were related to environmental (physicochemical) parameters to verify any kind of dependence. Data were statistically elaborated using hierarchical multilevel Bayesian models. Natural variability was found to be relevant across both space and time. The results of the present study proved that care should be paid when interpreting biomarker results. Further research is needed to better understand the dependence of the natural variability on environmental parameters. Environ Toxicol Chem 2017;36:3158-3167. © 2017 SETAC.

Oxylipins at intermediate larval stages of damselfly Coenagrion hastulatum as biochemical biomarkers for anthropogenic pollution

“…We hypothesized that developmental variability would have an impact on the capacity of oxylipins to indicate exposure. Developmental variability in various invertebrate species has been established for biochemical biomarkers such as CAT, ChE, and GST (Scarduelli et al 2017 ) but remains unknown for oxylipins. However, it is likely that also the fatty acid metabolism depends on developmental factors and has an impact on the levels and variability of oxylipins.…”

Environmental exposure and ecotoxicological properties of a new‐generation fluorosurfactant (cC6O4): A comparison with selected legacy perfluoroalkyl acids

“…Indeed, there is wide evidence in the literature that the relationship between the responses observed for the studied endpoints and ecologically relevant endpoints (e.g., reproduction, growth, population dynamics) cannot be defined (Forbes et al, 2006; Ippolito et al, 2017; Scarduelli et al, 2017). Moreover, many of the results fail to show a clear relationship between exposure (as concentration or exposure time) and response.…”

Genetic diversity and phylogenetic analysis of mayfly Caenis (Insecta: Ephemeroptera) using Cytochrome C Oxidase I (COI) and 12s rRNA genes from Thailand

“…Mayflies can be found in both lotic and lentic ecosystems of freshwater habitats all over the world, and in some cases brackish water; however, they are more abundant species-rich in the tropics and warm temperate regions. Nymphal stages develop in water containing higher levels of dissolved oxygen; therefore, they are important for freshwater ecology and qualified as bioindicators for pollution and water quality monitoring (Alhejoj et al 2014;Scarduelli et al 2017). Currently, approximately 40 families and more than 460 genera of mayflies have already been recognized worldwide (Jacobus et al 2019).…”