ABSTRACT
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 Olrog's 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 Olrog's gull.
Subject(s)
Brachyura/chemistry , Charadriiformes , Water Pollutants, Chemical/analysis , Animals , Argentina , Ecotoxicology , Endangered Species , Endosulfan/analysis , Endosulfan/pharmacokinetics , Geologic Sediments/analysis , Halogenated Diphenyl Ethers/analysis , Halogenated Diphenyl Ethers/pharmacokinetics , Polychlorinated Biphenyls/analysis , Polychlorinated Biphenyls/pharmacokinetics , Tissue Distribution , Water Pollutants, Chemical/pharmacokinetics , Wetlands , Zygote/chemistryABSTRACT
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 (Subject(s)
Bivalvia/metabolism
, Geologic Sediments/analysis
, Hydrocarbons, Chlorinated/analysis
, Insecticides/analysis
, Polycyclic Aromatic Hydrocarbons/analysis
, Tin Compounds/analysis
, Water Pollutants, Chemical/analysis
, Animals
, Argentina
, Bivalvia/chemistry
, Limit of Detection
, Polychlorinated Biphenyls/analysis
, Quality Control
ABSTRACT
The Patagonian coast is characterized by the existence of pristine ecosystems which may be particularly sensitive to oil contamination. In this study, a simulated oil spill at acute and chronic input levels was carried out to assess the effects of contamination on the macrobenthic community structure and the bioturbation activity of sediments sampled in Caleta Valdés creek. Superficial sediments were either noncontaminated or contaminated by Escalante crude oil and incubated in the laboratory for 30 days. Oil contamination induced adverse effects on macrobenthic community at both concentrations with, for the highest concentration, a marked decrease of approximately 40 and 55 % of density and specific richness, respectively. Besides the disappearance of sensitive species, some other species like Oligochaeta sp. 1, Paranebalia sp., and Ostracoda sp. 2 species have a higher resistance to oil contamination. Sediment reworking activity was also affected by oil addition. At the highest level of contamination, nearly no activity was observed due to the high mortality of macroorganisms. The results strongly suggest that an oil spill in this protected marine area with no previous history of contamination would have a deep impact on the non-adapted macrobenthic community.
Subject(s)
Ecosystem , Geologic Sediments , Petroleum Pollution , Animals , Argentina , Crustacea , Oligochaeta , PetroleumABSTRACT
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.
Subject(s)
Bacteria/metabolism , Ecosystem , Hydrocarbons/metabolism , Seawater/chemistry , Water Pollutants, Chemical/metabolism , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Biodegradation, Environmental , Biodiversity , Geologic Sediments/chemistry , Geologic Sediments/microbiology , Hydrocarbons/analysis , Molecular Sequence Data , Phylogeny , Seawater/microbiology , Water Pollutants, Chemical/analysisABSTRACT
Although sediments are the natural hydrocarbon sink in the marine environment, the ecology of hydrocarbon-degrading bacteria in sediments is poorly understood, especially in cold regions. We studied the diversity of alkane-degrading bacterial populations and their response to oil exposure in sediments of a chronically polluted Subantarctic coastal environment, by analyzing alkane monooxygenase (alkB) gene libraries. Sequences from the sediment clone libraries were affiliated with genes described in Proteobacteria and Actinobacteria, with 67 % amino acid identity in average to sequences from isolated microorganisms. The majority of the sequences were most closely related to uncultured microorganisms from cold marine sediments or soils from high latitude regions, highlighting the role of temperature in the structuring of this bacterial guild. The distribution of alkB sequences among samples of different sites and years, and selection after experimental oil exposure allowed us to identify ecologically relevant alkB genes in Subantarctic sediments, which could be used as biomarkers for alkane biodegradation in this environment. 16 S rRNA amplicon pyrosequencing indicated the abundance of several genera for which no alkB genes have yet been described (Oleispira, Thalassospira) or that have not been previously associated with oil biodegradation (Spongiibacter-formerly Melitea-, Maribius, Robiginitomaculum, Bizionia and Gillisia). These genera constitute candidates for future work involving identification of hydrocarbon biodegradation pathway genes.
Subject(s)
Alkanes/metabolism , Cytochrome P-450 CYP4A/genetics , Environmental Pollutants/metabolism , Gammaproteobacteria/genetics , Geologic Sediments/microbiology , Petroleum/metabolism , Antarctic Regions , Biodegradation, Environmental , DNA, Bacterial/genetics , DNA, Bacterial/metabolism , Gammaproteobacteria/isolation & purification , Gammaproteobacteria/metabolism , Hydrocarbons/metabolism , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA/methodsABSTRACT
The environmental quality of Ushuaia Bay, located at the southernmost tip of South America, is affected by the anthropogenic pressure of Ushuaia city. In this study, levels and sources of hydrocarbons in coastal sediments were assessed. Aliphatic hydrocarbon fractions ranged between 5.5 and 1185.3 µg/g dry weight and PAHs from not detected to 360 ng/g. Aliphatic diagnostic indices, the nalkanes homologous series occurrence, Aliphatic Unresolved Complex Mixtures (AliUCMs), and pristane and phytane isoprenoids indicated a petrogenic input. Some sites showed biogenic features masked by the anthropogenic signature. Particularly in port areas biodegradation processes were evident. PAH ratios showed a mixture of petrogenic and pyrogenic sources. Aliphatic and aromatic UCMs were strongly correlated, reflecting chronic pollution. Three areas were distinguished inside the bay: (1) east, with low hydrocarbons impact; (2) central, where hydrocarbons accumulation was related to source proximity and sediment characteristics; (3) south-west, where sediment characteristics and current circulation favour hydrocarbons accumulation.
Subject(s)
Geologic Sediments/chemistry , Polycyclic Aromatic Hydrocarbons/chemistry , Water Pollutants, Chemical/chemistry , Argentina , Bays , HumansABSTRACT
The Patagonian coast is considered a relatively pristine environment. However, studies conducted along coastal Patagonia have showed hydrocarbon pollution mostly concentrated at ports that have fishing, oil loading, general merchant, and/or tourist activities. A high value of total aliphatic hydrocarbons (TAH) was found at the Rawson fishing port (741 microg/g dw). In other ports with and without petroleum-related activities, hydrocarbon values were approximately 100 microg/g dw. The highest values for TAH and total aromatic hydrocarbons (TArH) were found in Faro Aristizábal, north of San Jorge gulf (1304 and 737 microg/g dw, respectively). This is very likely the result of petroleum-related activities at the Comodoro Rivadavia, Caleta Cordova, and Caleta Olivia ports located within this gulf. In other coastal areas away from potential anthropogenic sources, hydrocarbon values were less than 2 and 3 microg/g dw for TAH and TArH, respectively. This review of published and unpublished information suggests that ports are important oil pollution sources in the Patagonian coast. More detailed studies are needed to evaluate the area affected by port activities, to understand the mechanisms of hydrocarbon distribution in surrounding environments, and to assess bioaccumulation in marine organisms. Despite that some regulations exist to control oil pollution derived from port and docked vessel activities, new and stricter management guidelines should be implemented.
Subject(s)
Environmental Pollution/analysis , Hydrocarbons/analysis , Seawater/analysis , Water Pollution, Chemical/analysis , Argentina , Environmental Monitoring/methods , Geography , Petroleum/analysis , Water Pollutants, Chemical/analysisABSTRACT
The application of a surfactant from Bacillus subtilis O9 (Bs) on the bioremediation of soils polluted with crude oil was assayed in soil microcosms under laboratory conditions. Three concentrations of biosurfactant were assayed (1.9, 19.5, and 39 mg kg(-1) soil). Microcosms without biosurfactant were prepared as controls. During the experiment, the crude oil-degrading bacterial population, the aliphatic and aromatic hydrocarbons were monitored in each microcosm. The results indicated that applying Bs did not negatively affect the hydrocarbon-degrading microbial population Concentrations of 19 and 19.5mg (Bs) per kilogram of soil stimulated the growth of the population involved in the crude oil degradation, and accelerated the biodegradation of the aliphatic hydrocarbons. However, none of the assayed Bs concentrations stimulated aromatic hydrocarbon degradation.
Subject(s)
Bacillus subtilis/chemistry , Petroleum/metabolism , Soil Pollutants/metabolism , Surface-Active Agents/isolation & purification , Surface-Active Agents/pharmacology , Biodegradation, Environmental/drug effects , Ecosystem , Hydrocarbons/metabolism , Soil MicrobiologyABSTRACT
Se realizaron campañas a las zona de Bahia Nueva, en el Golfo Nuevo frente a la ciudad de Puerto Madryn y en la Bahia Engaño, cuando el objetivo de conocer la situacion actual de estas bahias, desde el punto de vista ambiental y la influencia que sobre las mismas tienen, los efluentes que en ellas se descargan. En el caso de la Bahia Nueva los efluentes provenientes de industrias, de la Cooperativa de Servicios Publicos y de vertidos pluviales que drenan permanentemente. En la Bahia Engaño se trata de conocer especificamente la influencia del rio Chubut
Subject(s)
Argentina , Bays , Back , Industrial Effluents Disposal , Sea Water Pollution , Water Quality , Bacteriological TechniquesABSTRACT
Se presenta la situación actual de estas bahías desde el punto de vista ambiental y la influencia que sobre las mismas tienen los efluentes que en ellas se descargan
Subject(s)
Agriculture , Argentina , Courses , Sewage , Agricultural Irrigation , Environment , Water PurificationABSTRACT
Se presenta la situación actual de estas bahías desde el punto de vista ambiental y la influencia que sobre las mismas tienen los efluentes que en ellas se descargan
Subject(s)
Argentina , Environment , Sewage , Water Purification , Agricultural Irrigation , Agriculture , CoursesABSTRACT
Se realizaron campañas a las zona de Bahia Nueva, en el Golfo Nuevo frente a la ciudad de Puerto Madryn y en la Bahia Engaño, cuando el objetivo de conocer la situacion actual de estas bahias, desde el punto de vista ambiental y la influencia que sobre las mismas tienen, los efluentes que en ellas se descargan. En el caso de la Bahia Nueva los efluentes provenientes de industrias, de la Cooperativa de Servicios Publicos y de vertidos pluviales que drenan permanentemente. En la Bahia Engaño se trata de conocer especificamente la influencia del rio Chubut
