Anthropic Impact Evaluation of Two Brazilian Estuaries Trough Biomarkers in Fish

Abstract

Coastal and estuarine areas can be impacted by several sources of anthropogenic activities derived from industries, agriculture, sewage and harbor activities. Two Brazilian estuarine areas (Piraquê-ES e Paranaguá-PR) located close to harbours, industries and sewage from urban centers were evaluated through analysis of somatic indexes, histopathological, biochemical and genetic biomarkers on fish. Histopathological lesions as lamellar fusion, hyperplasia, epithelial lifting, and second lamellae disorganization were found in gills. Necrosis was the main alteration observed in the liver of sampled animals and the occurrence of melano-macrophages in Cathorops spixii was similar among the evaluated areas. Cholinesterase activity increased in most of the contaminated areas. Genotoxic responses as micronucleus induction and occurrence of DNA strand breaks were detected in Piraquê and Paranaguá estuaries in all sampling seasons. Our results suggest that these areas are impacted by anthropogenic activities and that a multi-biomarker approach is valuable and recommended for environmental pollution evaluation.

First Evaluation of Genotoxicity of Macaé (Rj) Estuarine Waters

“…DNA damage observed in the zebrafish exposed to the estuarine waters of the Macaé River, which was 5.1 fold higher than the control after 48 h of exposure (comet assay), suggests the presence of genotoxic substances. The number of micronuclei found in this study (> 10 MN/thousand) is higher than the values observed for clams at the Guaíba hydrographic basin, which showed values between 4.5 to 6.9 MN/thousand at sites contaminated by urban effluents, metals and agriculture activities (Villela et al, 2007) and similar to values found in fish species (9.0 to 11 MN/thousand) located close to sources of contamination by industrial and urban discharges at Paranaguá estuary (Paraná state) (Domingos et al, 2009).…”

“…Aquatic organisms such as fish have been used as sentinels to monitor contamination with genotoxic chemicals (Lemos et al, 2007;Domingos et al, 2009) and Zebrafish used in the present study has been recently evaluated as potential in vivo model for genotoxicity (Chakravarthy et al, 2014).…”

Inhibition, recovery and field responses of Astyanax fasciatus (Cuvier, 1819) brain cholinesterases upon exposure to azinphos-methyl

“…OP from spraydrift usually resides in the water phase, while pesticides in contaminated runoff are to a large extent associated with suspended particles (Schulz, 2001;Gavilan et al, 2001;Barra et al, 2005;Sturm et al, 2007). Azinphos-methyl is, by-far, the most used pesticide at Dragon stream basin (Carrasco-Letelier et al, 2006 and this study), but obviously other pesticides with anticholinesterase activity (OP, carbamates), and even other pollutants (Valdez-Domingos et al, 2009) might contribute to changes found in fish cholinesterases. For instance, fishes collected from the S2 site (downstream to the farm area) in September show enzyme inhibitions very similar to those seen in specimens exposed to 0.01 mg L -1 azinphos-methyl in the laboratory bioassay.…”

“…Field data must be interpreted with extreme caution, since due to synergic, additive and antagonist responses, similar biomarker values can be achieved by different combinations of xenobiotics (Sandahl et al, 2005;Sturm et al, 2007;Laetz et al, 2009). In fact, many frequent pollutants have been shown to cause decreases or even increases in the activity of fish muscle cholinesterases, including heavy metals and hydrocarbons (Podolska & Napierska, 2006;Valdez-Domingos et al, 2009).…”

“…Thus, there is an urgent need to develop biomarkers using resident species that might be included in wide bio-surveillance programs. The sentinel species should be abundant, widely distributed, non-migratory and, on the other hand, it must respond as linearly and predictably as possible, and in the widest possible range of concentrations, to the agent to be monitored (Valdez-Domingos et al, 2009). Astyanax fasciatus is an abundant teleost which appears to combine most of these features, and that has been already proposed as a possible bioindicator of anthropogenic pollution (Schulz & Martins-Junior, 2000;Carrasco-Letelier et al, 2006;Moreira et al, 2010).…”