VERTICAL FLUXES OF POLYCYCLIC AROMATIC-HYDROCARBONS AND ORGANOCHLORINE COMPOUNDS IN THE WESTERN ALBORAN-SEA (SOUTHWESTERN MEDITERRANEAN)

Time-series samples of sinking particles were collected in the Alboran Sea with sediment traps moored at three water column depths (250, 500 and 750 m) between February and May 1992. The samples were analyzed f or individual polychlorobiphenyl congeners (i.e. PCBs IUPAC no.: 28, 5 2, 101, 118, 153, 138 and 180), chlorinated pesticides (DDE and Lindan e) and individual polycyclic aromatic hydrocarbons (PAHs; 3-6 aromatic rings), Average concentrations of PCB and total PAHs were 78.9 ng g(- 1) (range: 27.3-212) as Clophen A40 equivalents and 1176 ng g(-1) (ran ge: 104-2780), respectively. The 1,1-dichloro-2,2-bis(p-chlorophenyl)e thene (4,4'-DDE) and 1,2,3,4,5,6-hexachlorocyclohexane (gamma-HCH) wer e the only chlorinated pesticides identified throughout the sampling p eriod, with respective concentrations of 6.6 ng g(-1) (range 1.1-15) a nd 16.8 ng g(-1) (range 5.4-48). Corresponding fluxes of PCBs (as Clop hen A40 equivalents) and PAHs were 15.1 ng m(-2) d(-1) (range: 6.9-24. 9) and 225 ng m(-2) d(-1) (range: 15-625). Contaminant fluxes were ana lyzed with other collective fluxes obtained from the same samples (i.e . fecal pellets, mass and organic carbon); while higher molecular weig ht PAHs (MW > 228 daltons) exhibited a strong correlation with the mas s fluxes (r(2) = 90.7%, p < 0.001, n = 18), the lower molecular weight compounds (MW < 202 daltons) covaried with organic carbon and fecal p ellet fluxes (r(2) = 76.4%, p < 0.001, n = 18). The Sigma PCB fluxes c ovaried with organic carbon, and fecal pellet fluxes and depth (r(2) = 97.6%, p < 0.001, n = 9). The 4,4'-DDE only covaried with fluxes of o rganic carbon (r(2) = 85.87%, p < 0.001) and gamma-HCH with the fecal pellets fluxes and depth (r(2) = 85.2% and p = 0.001, n = 9). Comparis on with similar data from the northwestern Mediterranean and other oce ans suggests that the Alboran Sea is a relatively clean environment pr imarily due to its relative remoteness from input terrigenous sources.