J. Albaigés

Aliphatic and aromatic hydrocarbons in different sized aerosols over the Mediterranean Sea: Occurrence and origin

Marine aerosols were collected using a five-stage cascade impactor during the PHYCEMED II cruise in the Western Mediterranean Sea (October 1983). Their composition in aliphatic and aromatic hydrocarbons (HCs) was analyzed, representing the first time that concentrations of polynuclear aromatic HCs (PAH) are reported in relation to particle size for aerosols of remote marine areas. The HC concentrations were found to be dependent on the origin of the air masses. They were higher for air coming from North European countries than for air originating in the Atlantic and the South of Spain. The concentrations range between 7 and 14 ng m−3for n-alkanes and between 0.2 and 0.4 ng m−3for total PAH. Based on molecular criteria, several sources for these HCs have been identified: continental higher plant waxes, petroleum and pyrolysis (namely coal combustion and vehicular exhausts). Mass medium equivalent diameters (MMED) for the naturally derived n-alkanes are in the 1.79-2.53 μm range, indicating an origin related with the emission of large particles from higher plant waxes or from soil dusts. In contrast, MMED for the anthropogenic HCs, both aliphatic and aromatic, are smaller than the micron, suggesting initial emission of PAH through pyrolytic processes in the vapor phase followed by condensation onto larger sub-μm particles.

Bioaccumulation patterns of hydrocarbons and polychlorinated biphenyls in bivalves, crustaceans, and fishes.

Hydrocarbons and polychlorinated biphenyls (PCBs) were determined in tissues of marine organisms (mussels, crabs, benthic, and pelagic fishes) from six sites along the Catalan Coast (Western Mediterranean). Both aliphatic and aromatic hydrocarbons as well as seven PCB congeners (PCB-28, 52, 101, 118, 138, 153, 180) were quantified and differences in concentrations interpreted in terms of geographical distribution, trophic level, and biological cycle of the organisms. The bioaccumulation patterns of the different chemicals varied substantially. Hydrocarbons were metabolized along the food web, contrarily to PCBs, which exhibited a higher bioaccumulation in fishes. Considering 36 peaks of the GC-ECD profiles, encompassing 40 PCB congeners, from tri- to octa-chlorinated isomers, a relative enrichment was observed in the higher chlorinated ones from: mussels < mullets < tuna < crabs. The slopes of the correlation plots between the bioconcentration factor (log BCF) and the octanol-water partition coefficient (log Kow) for the different PCB congeners reflected the feeding behavior of the organisms, mussels exhibiting a preferential uptake by direct partitioning from water, and mullets and crabs with a certain uptake from sediments. Increasing metabolic degradation following a similar trend among species was also observed for aromatic hydrocarbons and PCB congeners containing meta and para vicinal H-atoms. Accordingly, mussels and benthic fishes were the best indicators of coastal pollution in the water column and sediments, respectively, although the above features should not be overlooked in the interpretation of biomonitoring data.

Sources and occurrence of C12C22n-alkane distributions with even carbon-number preference in sedimentary environments

Abstract The occurrence of C12C22n-alkanes with a strong even carbon-number preference is reported in recent and Miocene sediments, encompassing marine and freshwater systems, deposited under oxic and anoxic conditions. It is therefore shown that these n-alkanes can be found in a wider type of sedimentary environment than those previously described. The occurrence in some cases of a parallel distribution of C14C20n-alk-1-enes is also illustrated. A variety of biological sources, including both marine and freshwater bacteria as well as fungi and yeast species is suggested to account for such distributions.

Mass budget and dynamics of polycyclic aromatic hydrocarbons in the Mediterranean Sea

A mass budget was constructed to examine the status and dynamics of polycyclic aromatic hydrocarbons (PAHs) in the western Mediterranean Sea. Using gas chromatography-mass spectrometry, 11 PAHs have been quantified in atmospheric aerosols, rivers and seawater, sediment cores and sediment trap samples. Total PAH concentrations in Mediterranean aerosols range from 0.2 to 2 ng m−3, with 50–70% associated with the sub-micron particles. Maximum PAH concentrations were observed in winter when the concentrations were double those recorded in the spring. Total PAH inputs from the atmosphere were estimated to be from 35 to 70 t year−1 with a mean value of 47.5 t year−1 (wet/dry mean ratio of ∼2–3). Atmospherically-deposited PAH are dominated by the benzofluoranthenes. The total PAH riverine inputs amount to about 5.3−33 t year−1 from the Rhone river and 1.3 t year−1 from the Ebro river. The difference in these riverine fluxes is due to differences in annual water discharges and upstream land use. The total PAH accumulation rate in surficial sediments in the whole basin is estimated at 182 t year−1. Nearly 50% of the total PAHs accumulate in the 0–200 m water depth area supporting the importance of the coastal zone as a trap of terrigenous material and associated contaminants. Sediment trap experiments gave a mean residence time in the water column of total PAH (considering only particle settling) of 11 years, with higher residence times for high molecular weight PAHs. This supports the hypothesis that lower molecular weight PAHs are more efficiently removed from the water column. Water exchange resulted in a net outflow of 20 t year−1 and 2 t year−1 through the Gibraltar and Sicilian Straits, respectively. Atmospheric deposition and the Rhone River are the major contributors of PAH in the western Mediterranean. Sedimentation was identified as the major net output of PAH.

Effects of the “Aegean Sea” oil spill on biotransformation enzymes, oxidative stress and DNA-adducts in digestive gland of the mussel (Mytilus edulus L.)

Abstract Possible molecular biomarkers of impact by organic pollution on mussels were applied to samples from five sites along the Galician Coast, Spain, taken 6 months after the oil spill from the tanker “Aegean Sea.” Whole body aliphatic hydrocarbon concentrations were similar at all sites, but specific chemical ratios (resolved/unresolved hydrocarbons; carbon preference index; pristane/phytane) indicated a predominance of degraded petrogenic hydrocarbons nearer the oil spill. Levels of whole body polycyclic aromatic hydrocarbons (sum of 13 PAHs) increased steadily towards the oil spill, and were paralleled by increases in digestive gland levels of total cytochrome P-450, CYP1A-like protein and lipid peroxidation (corr. coeffs. with PAHs of 0.64–0.67). Differences were more marked in CYP1A-like protein than total cytochrome P450, indicating induction of specific P450 isoenzyme(s). No differences between sites were seen for benzo[a]pyrene hydroxylase, glutathione S-transferase, Superoxide dismutase and DT-diaphorase activities. Bulky, hydrophobic DNA-adducts were detected in digestive gland of mussels from industrial and urban sites, but not from the site nearest to the oil spill which had the highest tissue levels of PAHs. Overall the results indicate induction of cytochrome P450(s) and oxidative damage in mussel with oil exposure.

Bioaccumulation of organochlorinated contaminants in three estuarine fish species (Mullus barbatus, Mugil cephalus and Dicentrarcus labrax)

The bioaccumulation of organochlorinated contaminants (DDTs, PCBs and HCB) in three representative fish species from the Ebro Delta (western Mediterranean) was studied. The species, red mullet (Mullus barbatus), sea mullet (Mugil cephalus) and sea bass (Dicentrarchus labrax), were selected for their characteristic habitats and feeding behaviours to investigate their potential as bioindicators in pollution monitoring studies. Higher levels of PCBs and DDTs were generally found in red mullet and could be related to the higher lipid content of this species. Red mullet and sea bass exhibited a similar distribution pattern of these pollutants, whereas DDTs and HCB (hexaclorobenzene) were relatively more abundant in sea mullet, probably as a result of a direct uptake from the water lagoons from where the latter were collected and where these pollutants have been found in higher concentrations. A decrease in concentrations with size (age) was generally observed in red mullet and sea bass, though less clearly in sea mullet. This decrease was more pronounced for DDTs, probably owing to metabolic transformations. However, when data were normalized to lipid content, evidence for a positive uptake by sea mullet was obtained, probably relating to the larger growth rate of this species. These results indicate that the accumulation of organochlorine compounds in coastal fish from the same area depends on lipid content, habitat, dietary intake, growth rate and the metabolism of each species. Although these fish can be used for pollution monitoring, the subsequent variability of pollutant body burdens that are influenced by these factors precludes the extrapolation of data from one species to another.

Accuracy in the determination of the Kováts retention index : Mathematical dead time

Abstract The influence of several parameters on the viability and precision of the determination of the Kovats retention index, under conventional experimental conditions, has been examined. In particular, the activity of the support and the dead-time correction have been considered. A new mathematical method for the calculation of the dead time is given.

Bacterial communities from shoreline environments (Costa da Morte, Northwestern Spain) affected by the Prestige oil spill

ABSTRACT The bacterial communities in two different shoreline matrices, rocks and sand, from the Costa da Morte, northwestern Spain, were investigated 12 months after being affected by the Prestige oil spill. Culture-based and culture-independent approaches were used to compare the bacterial diversity present in these environments with that at a nonoiled site. A long-term effect of fuel on the microbial communities in the oiled sand and rock was suggested by the higher proportion of alkane and polyaromatic hydrocarbon (PAH) degraders and the differences in denaturing gradient gel electrophoresis patterns compared with those of the reference site. Members of the classes Alphaproteobacteria and Actinobacteria were the prevailing groups of bacteria detected in both matrices, although the sand bacterial community exhibited higher species richness than the rock bacterial community did. Culture-dependent and -independent approaches suggested that the genus Rhodococcus could play a key role in the in situ degradation of the alkane fraction of the Prestige fuel together with other members of the suborder Corynebacterineae. Moreover, other members of this suborder, such as Mycobacterium spp., together with Sphingomonadaceae bacteria (mainly Lutibacterium anuloederans), were related as well to the degradation of the aromatic fraction of the Prestige fuel. The multiapproach methodology applied in the present study allowed us to assess the complexity of autochthonous microbial communities related to the degradation of heavy fuel from the Prestige and to isolate some of their components for a further physiological study. Since several Corynebacterineae members related to the degradation of alkanes and PAHs were frequently detected in this and other supralittoral environments affected by the Prestige oil spill along the northwestern Spanish coast, the addition of mycolic acids to bioremediation amendments is proposed to favor the presence of these degraders in long-term fuel pollution-affected areas with similar characteristics.

Accumulation and distribution of biogenic and pollutant hydrocarbons, pcbs and ddt in tissues of western mediterranean fishes

Abstract Data on hydrocarbons, PCBs and total DDT in muscle, liver and gonads of Mullas barbatus. Trachurus trachurus, Merluccius merluccius, Engraulis enchrasicholus and Micromesistius poutassou collected along the Catalan Coast (NW Mediterrenean) are reported for the first time. The species and the collection sites—off Barcelona to the north (Palamos) and to the south (Ehro Delta)—were selected for the assessment of the effects of coastal pollutant sources on commercially valuable organisms. Mullus barbatus reflects the influence of local sources, and is therefore a useful bioindicator for organic pollutants. Despite some scattering of the results, concentrations are in general of the same order of magnitude for juvenile and adult specimens, although the pollutants considered exhibit different biological fates. Hydrocarbons are accumulated primarily in liver, whereas organochlorinated compounds are accumulated in gonads. Liver and muscle contents could reflect acute and chronic pollutants inputs respectively. The accumulation in muscle is more important for aromatic and chlorinated hydrocarbons than for the saturated ones, which are probably metabolized in the liver.

Characterization of the depositional environments of the Ebro Delta (western Mediterranean) by the study of sedimentary lipid markers

Abstract Thirty-seven sediment samples from the fresh/brackish water systems and the surrounding marine waters of the Ebro Delta have been analyzed for organic and inorganic carbon, carbohydrates, amino acids and lipids. The study of individual lipid components showed autochthonous and allochthonous contributions of organic materials to the system, namely higher plant residues, allochthonous soil-related components, macrophytes, unicellular algae and microbial residues. However, algal constituents are predominant in most sediments, suggesting that decomposition and remineralization of allochthonous organic matter, and subsequent enhancement of algal production, may be one of the major processes of the carbon cycle in the delta. The persistence of cycling intermediate and particularly labile compounds in the samples is constrained by environmental conditions of deposition. Accordingly, six depositional environments have been characterized (listed from more reducing to more oxic): the coastal lagoons, the bays, the river bed, the open sea area located around and far from the river mouth, and the coastal sandy sediments.