Bioaccumulation of organochlorine pesticides and PCBs by the narrownose smooth-hound shark in a nursery area of the Southwestern Atlantic

SCENNA LORENA; ONDARZA PAOLA MARIANA; CHIERICHETTI MELISA; SHIMABUKURO VALERIA; LO NOSTRO, FABIANA; MIGLIORANZA KARINA SILVIA BEATRIZ

Congreso; 12th Biennial Meeting Society of Environmental Toxicology and Chemistry; 2017

Coastal marine areas function as sinks for diverse anthropogenic contaminants, suchas Persistent Organic Pollutants (POPs) which included organochlorine pesticides(OCPs) and polychlorinated biphenyls (PCBs). POPs are lipophilic compounds thatbiomagnify in the food web. In this sense, chondrichthyans are able to accumulatesignificant concentrations of POPs due to their relative longevity, moderate to largesize, lipid-rich livers and high trophic position. The narrownose smooth-hound sharkMustelus schmitti is the most abundant and the most frequently landed sharks inArgentina. An important nursery area for this species is located in coastal waters of Southwestern Atlantic between 39º and 41º S (El Rincón Area, RA), where it developsan intensive agriculture production, commercial harbors and industries. For thatreason, levels and distribution of POPs were analyzed in liver and gonads of both sexesat different maturity stages and embryos of M. schmitti, captured in coastal waters ofRA. Concentrations were determined by GC-ECD and reported as ng/g wet weight.Livers of both sexes showed a predominance of PCBs, whereas gonads presentedsimilar proportions of OCPs and PCBs. In addition, concentrations were higher inlivers (OCPs=7.49±6.52, PCBs=12.38±11.48) than in gonads (OCPs=6.85±8.88,PCBs=5.25±4.98). In mature individuals, ovaries (14.29±11.12) presented higherconcentrations of POPs than testicles (2.31±2.01), but there were no differencescomparing immature gonads of females (14.03±7.39) and males (18.61±17.04). Theembryos in early stage of development, presented the same POPs pattern but a lowerlevel (8.94±6.76) that mature females. In all samples, endosulfan were the mostfrequent OCPs, 63 % of them shows a-/b-isomers ratios ≥1, suggesting the use of thetechnical mixture application for agricultural proposes before their ban in Argentina.The most abundant PCBs were tetra- (PCB-44) and hexa- (PCB-149, PCB-153)congeners, which could have stemmed from historical usage of Arochlor 1254 and1260. Our results revealed that land use in surrounding areas represents current sourcesof POPs to coastal marine waters. Chondrichthyans biaccumulate high levels of POPssince early stages of development. Therefore due to the low reproductive potential,long-term pollutants monitoring programs in coastal areas are necessary for fisherymanagement strategies and species conservation.