Persistent Organic Pollutants and chlorpyrifos in feathers of the threatened Olrog's gull (Larus atlanticus) wintering in southeastern Buenos Aires province, Argentina

QUADRI ADROGUE AGUSTINA; SECO PON JUAN PABLO; GARCÍA GERMAN OSCAR; CASTANO MELINA; COPELLO SOFIA; MIGLIORANZA KARINA SB

Encuentro; 8TH YOUNG ENVIRONMENTAL SCIENTISTS MEETING; 2019

Persistent Organic Pollutants (POPs) such as Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are anthropogenic chemicals characterized by their hydrophobicity, volatility and environmental persistence. These characteristics lead to them to be highly toxic, have considerable bioaccumulation and biomagnification in the food web. POPs were banned years ago and have been regulated since 2001 under the Stockholm Convention. Chlorpyrifos is an organophosphate insecticide currently in use, whose use has been increased following the banning of endosulfan in 2013. Marine birds, such as gulls, have been used as an indicator of chemical pollution of aquatic ecosystems given their trophic position; besides these species are capable to bioaccumulate pollutants in their tissues. In this context, the objective of this study was to determine levels of POPs and chlorpyrifos in feathers of the Olrog's gull (Larus atlanticus) and examine its relationship with sex and age class, during the non-breeding season in Mar Chiquita lagoon, Buenos Aires province, Argentina. POPs and chlorpyrifos were identified and quantified by gas chromatography with electron capture detector (GC-ECD). Chlorpyrifos was found in greater quantities among all the pollutants in all groups of individuals (= 262,93 ng/g), resulting from current agricultural practices. The highest values of POPs (males  = 280.45 ng/g, females  = 300.6 ng/g) were found in juvenile birds. OCPs were found in all sampled birds. Endosulfan was the main OCP group, which contributed to the total OCPs concentration in 33%, followed by HCHs with 28%. Among the PCBs, there was a predominance of dichlorbiphenyls and trichlorbiphenyls (#33, #44 and #31+28); these congeners have greater volatility and solubility than more chlorinated PCBs , which justifies the possible external deposition of these contaminants. The presence of hexachlorbiphenyls (#153 and #138) and PBDE-153 in juvenilebirds would be a consequence of the location of the nesting area, possibly next to the Bahia Blanca estuary, known for being a POPs hot spot. Concentrations of POPs and chlorpyrifos showed difference between sexes in subadults and adults birds, while levels found in males were higher than in females. Overall, the present study provides relevant information for the development of monitoring programs and regional strategies to improve the conservation status of the threatened Olrog's gull.