Can environmental factors increase oxidative responses in fish exposed to polycyclic aromatic hydrocarbons (PAHs)?

Relations among polycyclic aromatic hydrocarbons (PAHs), biomarkers of oxidative stress (lipid peroxidation, glutathione, and glutathione S-transferase activity), and the possible influence of environmental factors (temperature, pH, and salinity) were assessed in situ for specimens of Ramnogaster arcuata, a native estuarine fish. PAH levels found in the muscular tissue of R. arcuata ranged from 0.7 to 293.4 ng g-1 wet weight with petrogenic and pyrolytic inputs. Lipid peroxidation in the liver showed positive correlations (P < 0.05) with total PAHs (r = 0.66), 3-ring (r = 0.66) and 4-ring PAHs (r = 0.52) and glutathione in muscle (r = 0.58). Significant positive correlations (P < 0.05) were also evidenced between muscular glutathione with total (r = 0.62) and 3-ring PAHs (r = 0.75). Hepatic glutathione S-transferase negatively correlated with 4-ring PAHs (r = -0.58). These correlations suggest that lipid peroxidation and muscular glutathione could be good biomarkers for complex mixtures of PAHs, and hepatic glutathione S-transferase could be a suitable biomarker for 4-ring PAHs. Furthermore, significant correlations (P < 0.05) of environmental factors with PAH levels and biomarkers were observed, especially pH with 3-ring PAHs (r = -0.65), lipid peroxidation (r = -0.6), glutathione in the liver (r = -0.73) and muscle (r = -0.75); and temperature with 2-ring PAHs (r = -0.75) and glutathione in muscle (r = 0.51). The data suggest an influence of physicochemical parameters which could be driving a shift in PAH toxicity in R. arcuata. These results are essential for an integrated understanding of ecotoxicology and could help to predict environmental effects in present and future scenarios of ocean warming and acidification.

First assessment of debris pollution in the gastrointestinal content of juvenile Magellanic penguins (Spheniscus magellanicus) stranded on the west south Atlantic coasts.

This paper provides the first evidence of debris pollution, including plastic, in juvenile Magellanic penguins (Spheniscus magellanicus) found stranded on the Atlantic coast of southern Buenos Aires Province, Argentina. Macro-, meso- and microparticles of anthropogenic origin were observed in 100 % of the studied birds, with debris abundance ranging between 33 and 200 items/bird. Microparticles represented 91 % of the total debris and 97 % of them were fibers. Black particles were the most abundant (30 %), followed by transparent (26 %), blue (14 %), yellow (10.3 %), and red (10 %). Infrared and Raman spectroscopy identified 62.7 % of the total particles as plastics, with polypropylene (27.8 %) and polyester (21.6 %) being the most abundant polymers. Semi-synthetic cellulosic fibers, metallic particles, and pigments were also found. The presence of metallic microparticles was suggested for the first time in penguins. Stranded juvenile Magellanic penguins are proposed as promising bioindicators of plastic pollution in the South Atlantic.

Occurrence, behavior and the associated health risk of organochlorine pesticides in sediments and fish from Bahía Blanca Estuary, Argentina.

Organochlorine pesticides (OCPs) were assessed for their occurrence, behavior and the associated human health and ecological risks in four fish species (Micropogonias furnieri, Cynoscion guatucupa, Mustelus schmitti, and Ramnogaster arcuata) and sediments from the Bahía Blanca estuary, Argentina, an important coastal environment of South America. Total OCPs values ranged from 0.86 to 6.23 ng/g dry weight in sediments and from

Seasonal distribution pattern and bioaccumulation of Polycyclic aromatic hydrocarbons (PAHs) in four bioindicator coastal fishes of Argentina.

Polycyclic aromatic hydrocarbons (PAHs) are pollutants of global concern in coastal environments. They have a wide range of biological toxicity and due to their inherent properties, can easily bioaccumulate in organisms and concentrate in the environment. This work evaluated, in an integrated way, the seasonal PAH distribution patterns in sediments and four bioindicators fish species in a highly impacted estuary of Argentina; besides, their bioaccumulation patterns were assessed for the first time as indicator of ecological risk. The highest PAH levels in fish were found for Ramnogaster arcuata with an average of 64 ng g-1 w.w., followed by Micropogonias furnieri (45 ng g-1 w.w.), Cynoscion guatucupa (28 ng g-1 w.w.), and Mustelus schmitti (16 ng g-1 w.w.). Fish presented the highest PAH levels in fall with a predominance of petrogenic PAHs in colder seasons and pyrolytic PAHs in warmer seasons. Sediments presented an average of 233 ng g-1 d.w. with the same seasonal composition pattern of the fish tissues. Additionally, the data suggested that the main source of PAHs are wastewater discharges. The bioaccumulation factor (BAF) of PAHs in the tested fishes were found to range from 0.3 to 8. The highest values were observed during fall and winter, while bioaccumulation did not occur in moist spring and summer samples, which would suggest a high biotransformation process during these seasons. Results suggested that class III of juvenile C. guatucupa and M. furnieri, and adults R. arcuata are more sensitive bioindicators of chronic PAH contamination and that their bioaccumulation is independent of the compound hydrophobicity; this could have a positively influence on the criteria used for biological monitoring programs along the Atlantic coast. In addition, the presented BAF data on the target species will serve as a useful pollution indicator for South Atlantic coastal fish.