Marta G. Commendatore

Hydrocarbons in Coastal Sediments of Patagonia, Argentina: Levels and Probable Sources

Intertidal superficial sediment from the Patagonian coastal zone were analysed to determine the concentration and probable source of aromatic and aliphatic hydrocarbons. Concentrations of aromatic and aliphatic hydrocarbons ranged from non-detected to 737.6 μg/g and non-detected to 1304.7 μg/g of dry sediment, respectively. High concentrations were observed in San Jorge Gulf, where the main economic activities are based on crude oil production. The highest aromatic and aliphatic hydrocarbon concentrations were present at Faro Aristizabal, 200 km away from oil charging areas. As suspected, hydrocarbon levels in harbour areas were generally more important than at nearby zones. Lower or non-detected hydrocarbon levels were recorded at locations with low or non-anthropogenic activity. Alkane distribution indices and hydrocarbon distribution patterns were used to identify natural and anthropogenic inputs. The results showed recent crude oil inputs and contribution from remaining weathered residues at various locations, whereas biogenic compounds or biogenic in combination with anthropogenic hydrocarbons predominated in others.

Enhancement of hydrocarbon wastebiodegradation by addition of a biosurfactantfrom Bacillus subtilis O9

A non-sterile biosurfactant preparation (surfactin)was obtained from a 24-h culture of Bacillussubtilis O9 grown on sucrose and used to study itseffect on the biodegradation of hydrocarbon wastes byan indigenous microbial community at theErlenmeyer-flask scale. Crude biosurfactant was addedto the cultures to obtain concentrations above andbelow the critical micelle concentration (CMC). Lowerconcentration affected neither biodegradation normicrobial growth. Higher concentration gave highercell concentrations. Biodegradation of aliphatichydrocarbons increased from 20.9 to 35.5% and in thecase of aromatic hydrocarbons from nil to 41%,compared to the culture without biosurfactant. Theenhancement effect of biosurfactant addition was morenoticeable in the case of long chain alkanes. Pristaneand phytane isoprenoids were degraded to the sameextent as n-C17 and n-C18 alkanes and, consequently,no decrease in the ratios n-C17/pri and n-C18/phy wasobserved. Rapid production of surfactin crudepreparation could make it practical for bioremediationof ship bilge wastes.

Biosurfactant-enhanced degradation of residual hydrocarbons from ship bilge wastes

The use of Bacillus subtilis O9 biosurfactant (surfactin) and of bioaugmentation to improve the treatment of residual hydrocarbons from ship bilge wastes was studied. A biodegradation experiment was conducted in aquaria placed outdoors under non-aseptic conditions. Three treatments were examined: culture medium plus bilge wastes, bioaugmentation with microorganisms from bilge wastes, and bioaugmentation plus biosurfactant. Samples were analyzed for viable counts, aliphatic and aromatic hydrocarbon concentrations, n-C17/pristane and n-C18/phytane ratios. While the addition of biosurfactant stimulated hydrocarbon degradation, bioaugmentation did not produce any remarkable effect. At day 10, the remaining percentages of aliphatic and aromatic hydrocarbons in aquaria, which received biosurfactant, were 6.8 and 7.2, respectively, while it took 20 days to reach comparable results with the other treatments. The biosurfactant did not affect the preferential biodegradation of n-C17/pristane and n-C18/phytane. This biosurfactant, which can be produced in a relatively simple and inexpensive process, is a promising alternative in the optimization of hydrocarbon waste treatment. Journal of Industrial Microbiology & Biotechnology (2000) 25, 70–73.

Alkane biodegradation by a microbial community from contaminated sediments in Patagonia, Argentina

Biodegradation of a mix of normal alkanes (decane, dodecane, tetradecane, hexadecane, octadecane and eicosane) was studied in batch cultures after inoculating with microbial communities from pristine and hydrocarbon contaminated sediments. Analysis showed that the community from polluted sediments reduced the concentrations of all alkanes to < 5 mg l−1 after a 240-h incubation period (< 5% initial concentration), while the control community only degraded 5–10% of them. The hydrocarbon adapted community showed a lag phase of 48 h, in which no alkane biodegradation was found, followed by a 96-h growth period and a stationary phase from that moment, whereas the control community grew poorly. Isolated strains were mainly Gram-negative, motile and non-glucose fermenter rods. Based on these results, it could be concluded that the hydrocarbon adaptation of microorganisms led to an increase in alkane biodegradation. This capacity could be useful to improve biodegradation of hydrocarbon regional wastes.

Hydrocarbon levels in sediments and bivalve mollusks from Bahía Nueva (Patagonia, Argentina) : An assessment of probable origin and bioaccumulation factors

Effects of crude oil and its derived products on marine ecosystems are well known. Both aliphatic and aromatic fractions possess toxic properties that can affect marine organisms. Particularly, sixteen unsubstituted PAHs have been recognized as priority pollutants for the Word Health Organization, the Economic European Community, and the USA Environmental Protection Agency (Hellow et al., 1994). Many PAHs have been found to be carcinogenic in mammals and, consequently, there is concern over the mobilization of PAHs and their metabolites into marine food chains via bioaccumulation and trophic transfer from benthic fauna (Ferguson and Chandler, 1998). Determination of PAHs in marine organism tissues is necessary because of their carcinogenic and mutagenic properties (Noreña-Barroso et al., 1999). Mussels have been considered as pollution sentinels by many authors (i.e. Hellow et al., 2002) because of their bioaccumulation capacity, and the National Status and Trends Program (NOAA, 1993) recommended them as a foreground matrix to environment monitoring. Sediments are also ideal matrices for chemical analysis, as they are the final fate for a variety of lipophilic pollutants (Hellow et al., 2002), and reflect long-term deposition. Coastal environments of Patagonia, Argentina, are threatened by petroleum residues resulting from port activities as well as crude oil transport. Studies of intertidal sediments along this coast showed anthropogenic hydrocarbon pollution in several areas (Commendatore et al., 2000; Esteves et al., 2006; Commendatore and Esteves, 2007). However, there is scarce information about hydrocarbon levels at many sites of the Patagonian coast due to its large extension and limited resources to conduct evaluations ( 3000 Km). Bahía Nueva (BN) (42.75 S, 65.00 W Fig. 1) is a bay located in western Golfo Nuevo, at southern limit of Peninsula Valdés, UNESCO World Heritage Site. It has an area of 58 km and a mean depth of 30 m. Water temperature varies from 10 C in winter to 17.5 C in summer. Puerto Madryn city ( 80,000 inhabitants) located in this bay has tourism, fisheries and aluminum production as the most important economic activities. The city has two ports with an important maritime traffic. In addition, a high population growth rate and an increase in tourism during the last decade have augmented domestic sewage and groundwater drainage. Due to the lack of a complete sewage system, it is also very likely that polluted groundwater reaches the coast (Gil and Esteves, 2000). The main wastewater discharges into the Bay derive from fishery plant effluents; although the aluminum plant does not produce liquid effluents, pollutants likely to enter the sea through atmospheric deposition. These activities are potential sources of anthropogenic hydrocarbons which could affect economic resources and marine biodiversity. Water circulation inside the Bay flows northwards (Esteves et al., 1997) and is less than 2.5 cm s , depending mainly on the wind (Lanfredi, 1974; Krepper and Rivas, 1979; Rivas, 1983). Twelve and eight stations to obtain sediments and organisms, respectively, were sampled in areas close to petroleum hydrocarbon sources (ports, stations 7 and 10), groundwater drainage areas (stations 3–5), fishery effluents (station 11), previous urban sew-

Butyltins, polyaromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls in sediments and bivalve mollusks in a mid‐latitude environment from the Patagonian coastal zone

Butyltins (BTs), polyaromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) were assessed in a mid-latitude environment of the Patagonian coast, distant from significant pollutant sources. Bioaccumulation processes through bottom sediment resuspension were suggested by BTs level (expressed as ng of tin [Sn] g(-1) dry wt) found in surface sediment (<limit of detection [LOD]-166.5 ng [Sn] g(-1) dry wt) and bivalve mollusks (29.4-206.0 ng [Sn] g(-1) dry wt); whereas imposex incidence was only 15% in the gastropod Pareuthria plumbea collected near a harbor. Low hydrocarbon pollution was found in sediments and bivalves with ∑PAHs(16) ranging from <LOD to 94.9 ng g(-1) dry weight and from <LOD to 54.9 ng g(-1) dry weight, respectively. Values were typical of locations distant from pollutant sources and showed different compositional patterns for both substrates. However, concentrations for some individual PAHs in sediments were found over the threshold effect level. On average, ΣPCB did not exceed the sediment quality guidelines being 0.57 ± 0.88 ng g(-1) dry weight in sediments and 0.41 ± 0.26 ng g(-1) dry weight in bivalves. Average ΣOCPs in sediments were 0.53 ± 0.34 ng g(-1) dry weight and ranged from <LOD to 0.22 ng g(-1) dry weight in bivalves, showing a different pattern and suggesting a different accumulation pathway as was found for PAHs. Although both discrete and atmospheric sources can be considered for PAHs, organochlorines pollution was clearly related to atmospheric global transport, indicating that in the studied area, OCPs and PCBs experience permanent or temporal deposition during their migration to southern zones.

BTs, PAHs, OCPs and PCBs in sediments and bivalve mollusks in a mid‐latitude environment from the Patagonian coastal zone

Butyltins (BTs), polyaromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) were assessed in a mid-latitude environment of the Patagonian coast, distant from significant pollutant sources. Bioaccumulation processes through bottom sediment resuspension were suggested by BTs level (expressed as ng of tin [Sn] g(-1) dry wt) found in surface sediment (<limit of detection [LOD]-166.5 ng [Sn] g(-1) dry wt) and bivalve mollusks (29.4-206.0 ng [Sn] g(-1) dry wt); whereas imposex incidence was only 15% in the gastropod Pareuthria plumbea collected near a harbor. Low hydrocarbon pollution was found in sediments and bivalves with ∑PAHs(16) ranging from <LOD to 94.9 ng g(-1) dry weight and from <LOD to 54.9 ng g(-1) dry weight, respectively. Values were typical of locations distant from pollutant sources and showed different compositional patterns for both substrates. However, concentrations for some individual PAHs in sediments were found over the threshold effect level. On average, ΣPCB did not exceed the sediment quality guidelines being 0.57 ± 0.88 ng g(-1) dry weight in sediments and 0.41 ± 0.26 ng g(-1) dry weight in bivalves. Average ΣOCPs in sediments were 0.53 ± 0.34 ng g(-1) dry weight and ranged from <LOD to 0.22 ng g(-1) dry weight in bivalves, showing a different pattern and suggesting a different accumulation pathway as was found for PAHs. Although both discrete and atmospheric sources can be considered for PAHs, organochlorines pollution was clearly related to atmospheric global transport, indicating that in the studied area, OCPs and PCBs experience permanent or temporal deposition during their migration to southern zones.

Distribution and bioaccumulation of butyltins in the edible gastropod Odontocymbiola magellanica

ABSTRACT Butyltins (BTs) were found in sediments and body tissues of the edible gastropod Odontocymbiola magellanica, in which imposex has been recorded since 2000. BTs in sediments ranged from < MDL to 174.8 ng (Sn) g−1 for TBT, < MDL to 19.2 ng (Sn) g−1 for DBT, and < MDL to 71.8 ng (Sn) g−1 for MBT. In body tissues BTs varied from < MDL to 147.1, < MDL to 77.0 and < MDL to 345.3 ng (Sn) g−1 for TBT, DBT and MBT, respectively. BT concentrations were higher in gonads and digestive glands than in the albumen gland and foot (edible). The highest concentrations of BTs in both sediments and gastropods were found in the harbour area, decreasing with distance to the harbour and areas with less maritime traffic. The Biota-Sediment Accumulation Factor (BSAF) in the different organs was between 0.02–0.42, 0.09–0.35 and 0.08–5.25 for TBT, DBT and MBT, respectively. There were positive correlations between concentrations of BTs in sediments and gastropod body tissues, suggesting that xenobiotic accumulation in O. magellanica occurs mainly through contaminated sediments, rather than water or the food chain. Considering current sediment quality guidelines, our results indicate that acute toxic effects would be expected from TBT exposure, which represents a serious environmental threat for the benthic community. Although the levels of BTs found in the foot of this edible gastropod did not exceed the recommended Tolerable Daily Intake in polluted areas, they should be monitored to ensure the safety of seafood consumers. The alternative antifouling biocides Irgarol and Diuron were not detected in sediments.

The Bacterial Community Structure of Hydrocarbon-Polluted Marine Environments as the Basis for the Definition of an Ecological Index of Hydrocarbon Exposure

The aim of this study was to design a molecular biological tool, using information provided by amplicon pyrosequencing of 16S rRNA genes, that could be suitable for environmental assessment and bioremediation in marine ecosystems. We selected 63 bacterial genera that were previously linked to hydrocarbon biodegradation, representing a minimum sample of the bacterial guild associated with this process. We defined an ecological indicator (ecological index of hydrocarbon exposure, EIHE) using the relative abundance values of these genera obtained by pyrotag analysis. This index reflects the proportion of the bacterial community that is potentially capable of biodegrading hydrocarbons. When the bacterial community structures of intertidal sediments from two sites with different pollution histories were analyzed, 16 of the selected genera (25%) were significantly overrepresented with respect to the pristine site, in at least one of the samples from the polluted site. Although the relative abundances of individual genera associated with hydrocarbon biodegradation were generally low in samples from the polluted site, EIHE values were 4 times higher than those in the pristine sample, with at least 5% of the bacterial community in the sediments being represented by the selected genera. EIHE values were also calculated in other oil-exposed marine sediments as well as in seawater using public datasets from experimental systems and field studies. In all cases, the EIHE was significantly higher in oiled than in unpolluted samples, suggesting that this tool could be used as an estimator of the hydrocarbon-degrading potential of microbial communities.

Persistent organic pollutants in sediments, intertidal crabs, and the threatened Olrog's gull in a northern Patagonia salt marsh, Argentina

Persistent organic pollutants (POPs) are of great concern for the environment. In this study we (a) determine levels and distribution of OCPs, PCBs, and PBDEs in sediments and two crab species (Neohelice granulata and Cyrtograpsus altimanus), (b) assess bioaccumulation in crabs, and (c) explore the occurrence of POPs in the Near Threatened Olrogs gull (Larus atlanticus) chicks and eggs in one of the most important salt marsh environments in the South West Atlantic. Sediments, crabs, and gull chicks and eggs showed POPs presence at low levels; being α-endosulfan, PCB-153, and BDE-47 the most represented compounds. In sediments, pollutant concentrations were lower than those reported in Canadian guidelines for the protection of the aquatic life. POP bioaccumulation was recorded in crabs, suggesting a risk to upper trophic level predators. Further studies are needed to understand the trophic effects of POPs in San Blas bay, particularly on the threatened Olrogs gull.