Bioaccumulation of anthropogenic contaminants by detritivorous fish in the Rı´o de la Plata estuary: 1-Aliphatic hydrocarbons

J.C. COLOMBO; N. CAPPELLETTI; M.C. MIGOYA; E. SPERANZA

CHEMOSPHERE

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2007 vol. 68 p. 2128 - 2135

0045-6535

The temporal variability and bioaccumulation dynamics of C12?25 n-alkanes, isoprenoids and unresolved aliphatic hydrocarbons (UCM) were studied in a detritivorous fish (Sàbalo: Prochilodus lineatus) collected from 1999 to 2005 in the sewage impacted Buenos Aires coastal area. Fish muscles contain huge amounts of n-C12?25 (165 ± 93, 70 ± 48 or 280 ± 134 lg g1, dry, fresh and lipid weight, respectively) and UCM (931 ± 560, 399 ± 288 and 1567 ± 802 lg g1) reflecting the chronic bioaccumulation of fossil fuels from sewage particulates. On a temporal basis, lipid normalized aliphatic concentrations peaked by the end of 2001?2002 during the rainiest period over the last four decades (1750 vs. 1083 ± 4.6 mm in 1999, 2004 and 2005), reflecting an enhanced exposition due to massive anthropogenic fluxes from Metropolitan Buenos Aires in wet years. The hydrocarbon composition in fish muscles is enriched in n-C15?17 and isoprenoids relative to a fresh crude oil and settling particulates, with fresher signatures during the 2001?2002 maxima. Fish/settling material bioaccumulation factors (BAFs: 0.4?6.4 dry weight or 0.07?0.94 lipid-organic carbon) plotted against Kow showed a parabolic pattern maximizing at n-C14?18 and isoprenoids. The optimal bioaccumulation window corresponds to highly hydrophobic (logKow: 7.2? 9.9), intermediate-size C14?18 n-alkanes and C15?20 isoprenoids (MW: 198?282; length: 17.9 to 25.4A ˚ ) with melting points ranging from 19.8 to 28 C. The uptake efficiency is inversely correlated to melting points and increased from 75% for n-C25 to above 90% for n-C14?15 and isoprenoids.