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

CHIERICHETTI M.; SCENNA L.; MIGLIORANZA K.S.B.; SHIMABUKURO V.M.,; ONDARZA P.M.; LO NOSTRO F.

Santos, SP

Congreso; 12th Biennial Meeting Society of Environmental Toxicology and Chemistry Latino América (SETAC LA).; 2017

Society of Environmental Toxicology and Chemistry Latino América

Coastal marine areas function as sinks for diverse anthropogenic contaminants, such as Persistent Organic Pollutants (POPs) which included organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). POPs are lipophilic compounds that biomagnify in the food web. In this sense, chondrichthyans are able to accumulate significant concentrations of POPs due to their relative longevity, moderate to large size, lipid-rich livers and high trophic position. The narrownose smooth-hound shark Mustelus schmitti is the most abundant and the most frequently landed sharks in Argentina. 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 develops an intensive agriculture production, commercial harbors and industries. For that reason, levels and distribution of POPs were analyzed in liver and gonads of both sexes at different maturity stages and embryos of M. schmitti, captured in coastal waters of RA. Concentrations were determined by GC-ECD and reported as ng/g wet weight. Livers of both sexes showed a predominance of PCBs, whereas gonads presented similar proportions of OCPs and PCBs. In addition, concentrations were higher in livers (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 higher concentrations of POPs than testicles (2.31±2.01), but there were no differences comparing immature gonads of females (14.03±7.39) and males (18.61±17.04). The embryos in early stage of development, presented the same POPs pattern but a lower level (8.94±6.76) that mature females. In all samples, endosulfan were the most frequent OCPs, 63 % of them shows a-/b-isomers ratios ≥1, suggesting the use of the technical 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 and 1260. Our results revealed that land use in surrounding areas represents current sources of POPs to coastal marine waters. Chondrichthyans biaccumulate high levels of POPs since early stages of development. Therefore due to the low reproductive potential, long-term pollutants monitoring programs in coastal areas are necessary for fishery management strategies and species conservation.