Biomarkers in an invasive fish species, Oreochromis niloticus, to assess the effects of pollution in a highly degraded Brazilian River

Multi-biomarker responses as indication of contaminant effects in Gambusia affinis from impacted rivers by municipal effluents

“…There was an obvious seasonal variation of contaminant load in the river water and biological effects in mosquitofish, which may be due to the difference of precipitation, surface runoff, municipal wastewater discharges or other factors between seasons. Various types of biomarkers have been used for assessing the toxic effect of contaminants in environmental risk assessment (Linde-Arias et al, 2008). Toxic effects at higher organization levels can be analyzed with parameters involving whole tissues or the whole organism (Olivares et al, 2010).…”

“…Toxic effects at higher organization levels can be analyzed with parameters involving whole tissues or the whole organism (Olivares et al, 2010). Previous studies have highlighted the usefulness of integrating a set of different biomarkers when assessing the biological effects in polluted environments since a single biomarker may not reflect the health status of a sentinel species (Frenzilli et al, 2008;Linde-Arias et al, 2008). Prior to death or overt sickness, organisms may respond to stress by changing biological responses.…”

“…Prior to death or overt sickness, organisms may respond to stress by changing biological responses. Understanding these changes of biological responses may provide an early warning of later, much more serious consequences (Linde-Arias et al, 2008).…”

“…More importantly, some biomarkers can be specific to particular chemical classes such as heavy metals, planar aromatic compounds, pesticides, and environmental estrogens (Roberts et al, 2005). For example, in certain animals, including fish, metallothionein (MT) is low molecular-mass cysteine-rich metalbinding protein that is capable of being induced by heavy metals (Hansen et al, 2006;Linde-Arias et al, 2008). Cytochrome P4501A (CYP1A) plays an important role in catalyzing oxidative metabolism of organic pollutants and has been used as a specific biomarker for exposure to aryl hydrocarbon receptor (AhR) agonists in fish such as PAHs and polychlorobiphenyls (PCBs) (Olivares et al, 2010;Maes et al, 2013).…”

“…However, although some biomarkers can be specific to particular chemical classes, they may also be affected by other chemical classes. Therefore, the integrated use of a wide battery of selected biomarkers is a sound procedure to minimize misinterpretation in complex environmental pollution situations (Linde-Arias et al, 2008).…”