Metabolomics of Ulva lactuca Linnaeus (Chlorophyta) exposed to oil fuels: Fourier transform infrared spectroscopy and multivariate analysis as tools for metabolic fingerprint.

Fossil fuels, e.g. gasoline and diesel oil, account for substantial share of the pollution that affects marine ecosystems. Environmental metabolomics is an emerging field that may help unravel the effect of these xenobiotics on seaweeds and provide methodologies for biomonitoring coastal ecosystems. In the present study, FTIR and multivariate analysis were used to discriminate metabolic profiles of Ulva lactuca after in vitro exposure to diesel oil and gasoline, in combinations of concentrations (0.001%, 0.01%, 0.1%, and 1.0% - v/v) and times of exposure (30min, 1h, 12h, and 24h). PCA and HCA performed on entire mid-infrared spectral window were able to discriminate diesel oil-exposed thalli from the gasoline-exposed ones. HCA performed on spectral window related to the protein absorbance (1700-1500cm-1) enabled the best discrimination between gasoline-exposed samples regarding the time of exposure, and between diesel oil-exposed samples according to the concentration. The results indicate that the combination of FTIR with multivariate analysis is a simple and efficient methodology for metabolic profiling with potential use for biomonitoring strategies.

Long-term weathering and continued oxidation of oil residues from the Deepwater Horizon spill.

To investigate the long-term weathering of oil from the Deepwater Horizon (DWH) incident, oil-soaked sand patties were collected from Gulf of Mexico beaches from Florida to Alabama over a three-year period from 2012 to 2014. Analysis of oil residues by gas chromatography with flame ionization detection (GC-FID), thin-layer chromatography with flame ionization detection (TLC-FID), and Fourier transform infrared spectroscopy (FT-IR) indicated uniformity in their chemical composition. Some variability within and between samples was observed, arising from differences in exposure to light and water, which increase the amount of weathering. Oxygenated hydrocarbons (OxHC) produced by weathering processes dominate the majority of oil residues. These OxHC have continued recalcitrance in the environment, and increase in relative abundance over time. Analyses of the bulk characteristics of oil residues via TLC-FID and FT-IR should be continued as these techniques provide important insight into the weathering state of oil residues.

Silver bonded to silica gel applied to the separation of polycyclic aromatic sulfur heterocycles in heavy gas oil.

Silica gel containing silver ions was prepared and characterized. Silica was organofunctionalized with 3-mercaptopropyl group by using grafting reaction followed by silver ions adsorption (silver covalently bonded to mercaptopropyl silca gel, Ag-MPSG). The organofunctionalization and silver coordination were observed by transmission infrared spectroscopy and elemental analyses (CHN and EDS). The textural characteristics were studied by N2 adsorption-desorption isotherms. Additionally, optical properties were studied by diffuse reflectance spectroscopy. The Ag-MPSG material was employed as stationary phase for the first time for fractionation of a heavy gas oil sample resulting in a fraction that is richer in polycyclic aromatic sulfur heterocycles (PASH). The fractions were analyzed by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detector and Ag-MPSG material provided similar fractionation performance when compared to conventional material [palladium covalently bonded to mercaptopropyl silca gel, Pd(II)-MPSG] usually employed for the same purpose and as the cost of silver is less than the one of palladium, the cost of the fractionation phase was reduced.

Diagnosing the level of stress on a mangrove species (Laguncularia racemosa) contaminated with oil: A necessary step for monitoring mangrove ecosystems.

Monitoring the effects of pollution on mangrove vegetation is a challenge. A specific study using an oil spill simulation on mangrove species was conducted to address this challenge. We tested the effectiveness of the chlorophyll a fluorescence kinetics as a fast and robust method to diagnose the vitality of Laguncularia racemosa. We used L. racemosa plants contaminated with marine fuel oil in mangrove microcosm models. Several parameters of the JIP-test were capable of detecting the impairment of the photosynthetic function prior to the visual manifestation of symptoms in response to oil contamination. The results support the use of the chlorophyll fluorescence transient as a reliable, fast and easy to apply diagnostic method for evaluating oil-impacted mangroves. To the best of our knowledge, it is the first time that consistent data showing photosynthetic impairment in response to oil contamination is shown for a mangrove tree species.

Production of rhamnolipids and diesel oil degradation by bacteria isolated from soil contaminated by petroleum.

Biosurfactants are microbial secondary metabolites. The most studied are rhamnolipids, which decrease the surface tension and have emulsifying capacity. In this study, the production of biosurfactants, with emphasis on rhamnolipids, and diesel oil degradation by 18 strains of bacteria isolated from waste landfill soil contaminated by petroleum was analyzed. Among the studied bacteria, gram-positive endospore forming rods (39%), gram positive rods without endospores (17%), and gram-negative rods (44%) were found. The following methods were used to test for biosurfactant production: oil spreading, emulsification, and hemolytic activity. All strains showed the ability to disperse the diesel oil, while 77% and 44% of the strains showed hemolysis and emulsification of diesel oil, respectively. Rhamnolipids production was observed in four strains that were classified on the basis of the 16S rRNA sequences as Pseudomonas aeruginosa. Only those strains showed the rhlAB gene involved in rhamnolipids synthesis, and antibacterial activity against Escherichia coli, P. aeruginosa, Staphylococcus aureus, Bacillus cereus, Erwinia carotovora, and Ralstonia solanacearum. The highest production of rhamnolipids was 565.7 mg/L observed in mineral medium containing olive oil (pH 8). With regard to the capacity to degrade diesel oil, it was observed that 7 strains were positive in reduction of the dye 2,6-dichlorophenolindophenol (2,6-DCPIP) while 16 had the gene alkane mono-oxygenase (alkB), and the producers of rhamnolipids were positive in both tests. Several bacterial strains have shown high potential to be explored further for bioremediation purposes due to their simultaneous ability to emulsify, disperse, and degrade diesel oil. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:262-270, 2016.

Physiological aspects of mangrove (Laguncularia racemosa) grown in microcosms with oil-degrading bacteria and oil contaminated sediment.

To assess the severity of oil spills on mangroves, diagnosis of the vegetation health is crucial. Some aspects of photosynthesis such as photochemical efficiency and leaf pigment composition together with the level of oxidative stress may constitute reliable indicators for vegetation health. To test this approach 14 month old Laguncularia racemosa were contaminated with 5 L m(-2) of the marine fuel oil MF-380 and treated with an oil degrading bacterial consortium in microcosms. Contamination resulted in a 20% decrease in shoot dry weight after 128 days. Photochemical efficiency, pigment content, catalase and ascorbate peroxidase remained unchanged. Multivariate ordination of DGGE microbial community fingerprints revealed a pronounced separation between the oil contaminated and the non-contaminated samples. Further studies are necessary before physiological parameters can be recommended as indicators for plant's health in oil polluted mangroves.

Revisão: propriedades físico-químicas do biodiesel / Physicochemical properties of biodiesel: a review

Esta revisão de literatura teve como objetivo descrever aspropriedades físico-químicas do biodiesel obtido a partir de diferentesmatérias-primas. Foram estudados dados de viscosidade, densidade,número de cetanos, ponto de fulgor, ponto de fluidez, ponto de névoae poder calorífi co de biodiesel obtido de óleo de soja, de coco, farelode arroz, algodão, pequi, babaçu, mamona, palma, dendê, girassol,milho, canola, pinhão manso e karanja. Considerando a diversidadede fontes vegetais e animais que podem gerar biodiesel ressaltasea carência de dados de propriedades físico-químicas para asmatérias-primas ainda inexploradas. Espera-se com este trabalhocontribuir para a criação de banco de dados de propriedades físicoquímicasdo óleo e do biodiesel de diferentes fontes, o que permitiráprojetar e dimensionar tanto os equipamentos necessários à linhade produção quanto motores alternativos.

Gold, coal and oil.

Jared Diamond has hypothesized that guns, germs and steel account for the fate of human societies. Here I propose an extension of Diamond's hypothesis and put it in other terms and dimensions: gold, coal and oil account not only for the fate of human societies but also for the fate of mankind through the bodily accumulation of anthropogenic arsenic, an invisible weapon of mass extinction and evolutionary change. The background is clear; arsenic species fulfill seven criteria for a weapon of mass extinction and evolutionary change: (i) bioavailability to all living organisms; (ii) imperceptibility; (iii) acute toxicity; (iv) bioaccumulation and chronic toxicity; (v) adverse impact on reproductive fitness and reproductive outcomes and early-age development and growth in a wide range of microbial, plant and animal species including man; (vi) widespread geographical distribution, mobility and ecological persistence on a centennial to millennial basis and (vii) availability in necessary and sufficient amounts to exert evolutionarily meaningful effects. The proof is becoming increasingly feasible as human exploitation of gold, coal and oil deposits cause sustainable rises of arsenic concentrations in the biosphere. Paradoxically, humans are among the least arsenic-resistant organisms because humans are long-lived, encephalized and complex social metazoans. An arsenic accumulation model is presented here to describe how arsenic accumulates in the human body with increasing age and at different provisionally safe exposure levels. Arsenic accumulates in the human body even at daily exposure levels which are within the lowest possible WHO provisional tolerance limits, yielding bodily arsenic concentrations which are above WHO provisional limits. Ongoing consequences of global scale arsenic poisoning of mankind include age-specific rises in morbidity and mortality followed by adaptive changes. The potential rise of successful forms of inborn resistance to arsenic in humans will make it certain that a number of other hardly won, nicely balanced human-specific adaptednesses will decline. These include a decline of encephalization and life-span, and consequentially intelligence and longevity. These changes are likely to have far-reaching impacts on biological and cultural evolution of mankind. The only efficient way of reducing chronic global exposure to arsenic and avoiding further human losses is the inactivation of important sources of anthropogenic arsenic such as hard rock mining and burning of fossil fuels.

Assessing petroleum oils biodegradation by chemometric analysis of spectroscopic data.

This study was conducted to classify petroleum oils in terms of their biodegradation stage by using spectroscopic analysis associated to chemometric treatments. Principal Component Analysis (PCA) has been applied on infrared and UV fluorescence spectra of Brazilian and Pyrenean oils. For Brazil samples, the method allowed to distinguish the biodegraded oils from the non-affected ones. Pyrenean sampling including oils at different levels of biodegradation has been chosen to follow their alteration rate. PCA loadings have shown spectral regions which have differentiated oils after biodegradation whereas Simple-to-use Interactive Self-Modelling Mixture Analysis (SIMPLISMA) has permitted to obtain a repartition in terms of components families (saturated, aromatic and polar ones) characterizing chemical composition of oils at different biodegradation degrees. Results are in good agreement with conclusions of usual hydrocarbon biomarker analysis.

Sub-soil contamination due to oil spills in six oil-pipeline pumping stations in northern Mexico.

Mexico has a very important oil industry, comprehending the exploration, production, transformation, storage and distribution of crude oil and its fractions. Petroleos Mexicanos (PEMEX) is a state-owned monopoly in charge of these activities. Oil and oil-products transport is an extremely crucial operation for the cycle production-transformation-distribution. Pipeline system transport crude oil and sub-products along the country (including liquids, gases and mixtures). It has been reported that more than 30% of the oil ducts in Mexico have been operating for over 30 years, although their lifetime has been calculated in 25-30 years. This work is aimed at characterizing a zone around six oil-pipeline pumping stations located at northern Mexico. The specific places to evaluate soil contamination were (1) the distribution head of the Gomez Palacio (GOPA) pumping station; (2) the north side of the old ditch, the API oil separator and the wastewater zones of the Jimenez (JIM) pumping station; (3) the pumping stations of Ceballos (CE), Peronal (PER), Simon Bolivar (SIBO), and Mayran (MAY). The study comprehended sampling of the areas, delimitation of contamination in the vertical and horizontal extension, analysis of the sampled soils, regarding TPH and, in some cases, the 16 PAHs considered as a priority by USEPA, calculation of areas and volumes contaminated (according to the Mexican legislation, specifically NOM-EM-138-ECOL-2002) and, finally, a proposal for the best remediation techniques suitable for the encountered contamination levels and the localization of contaminants. In general, TPHs were found in all the pumping stations analyzed in this study. Regarding maximal TPHs concentrations at the stations, their order of contamination was as follows: SIBO>CE>PER>MAY>JIM>GOPA. PAHs were found only in a few points at concentrations above the detection limit. At the Jimenez, Gomez Palacio, Peronal, and Ceballos stations, only one point, with PAHs values over the detection limit was found, whereas two points were found at Mayran, and finally at the Simon Bolivar station there were four points with measurable amounts of PAHs. Given the areas and volumes that need to be treated (32835 m3), as well as the physical position of contaminants, it is considered that excavation of the contaminated soil is feasible and the cleaning process could be soil washing assisted with surfactants, though bioremediation should not been discharged as a possible remediation technique.

Micronucleus test and observation of nuclear alterations in erythrocytes of Nile tilapia exposed to waters affected by refinery effluent.

Micronuclei and nuclear alterations tests were performed on erythrocytes of Oreochromis niloticus (Perciformes, Cichlidae) in order to evaluate the water quality from Paraíba do Sul river, in an area affected by effluents from an oil shale processing plant, located in the city of São José dos Campos, Brazil-SP. Water samples were collected on 2004 May and August (dry season) and on 2004 November and 2005 January (rain season), in three distinct sites, comprising 12 samples. It was possible to detect substances of clastogenic and/or aneugenic potential, as well as cytotoxic substances, chiefly at the point corresponding to the drainage of oil shale plant wastes along the river. The highest incidence of micronuclei and nuclear alterations was detected during May and August, whereas the results obtained in November and January were insignificant. This work shows that the effluent treatment provided by the oil shale plant was not fully efficient to minimize the effect of cytotoxic and mutagenic substances in the test organism surveyed.

Subsoil TPH and other petroleum fractions-contamination levels in an oil storage and distribution station in north-central Mexico.

Many oil industry related sites have become contaminated due to the activities characteristic of this industry, such as oil exploration and production, refining, and petro-chemistry. In Mexico, reported hydrocarbon spills for the year 2000 amounted to 185203, equivalent to 6252 tons (PEMEX, 2000). The first step for the remediation of these polluted sites is to assess the size and intensity of the oil contamination affecting the subsoil and groundwater, followed by a health risk assessment to establish clean up levels. The aim of this work was to characterize the soil and water in a north-central Mexico Oil Storage and Distribution Station (ODSS), in terms of TPHs, gasoline and diesel fractions, BTEX, PAHs, MTBE, and some metals. Besides, measurements of the explosivity index along the ODSS were made and we describe and discuss the risk health assessment analysis performed at the ODSS, as well as the recommendations arising from it. Considering soils with TPH concentrations higher than 2000 mg kg(-1), the contaminated areas corresponding to the railway zone is about 12776.5 m2, to the south of the storage tanks is about 6558 m2, and to the south of the filling tanks is about 783 m2. Total area to be treated is about 20107 m2 (volume of 20107 m3), considering 1m depth.

Hidrocarburos de petróleo, disueltos y dispersos, en cuatro ambientes costeros de Costa Rica / Oil pollution status expressed as the fraction of dissolved and dispersed petroleum hydrocarbons

Entre los años 2000 a 2002 se recolectaron y se analizaron 130 muestras de agua de mar en las costas de Costa Rica, para determinarles la concentración de hidrocarburos de petróleo disueltos y dispersos (HPDD), referida a equivalentes de criseno en hexano, y expresada como µg·L-1. Se utilizó la técnica analítica de fluorescencia molecular. 42 muestras correspondieron al Caribe (Moín) y 81 al Pacífico (Bahía Culebra, Golfo de Nicoya, Golfo Dulce y en una ocasión se tomaron muestras a lo largo del Estero de Puntarenas). En la zona costera de Moín el promedio de la concentración de HPDD fue 0.10 µg·L-1, con una desviación estándar de ± 0.18 µg·L-1, en un ámbito desde concentraciones no detectables por el método, (nd), hasta 0.65 µg·L-1. En el Pacífico las concentraciones para todo el período del estudio, estuvieron entre nd y 0.37 µg·L-1. En la Bahía Culebra no se detectaron HPDD en ninguna de las muestras (n = 12); en el Golfo de Nicoya el promedio y la desviación estándar fueron 0.04 µg·L-1 ± 0.09 µg·L-1 (n = 51), en un ámbito desde nd hasta 0.33 µg·L-1. En el Golfo Dulce el promedio y la desviación estándar fueron 0.05 µg·L-1 ± 0.11 µg·L-1 (n = 18), en el ámbito desde nd a 0.37 µg·L-1. Durante las fechas en que se llevó a cabo el muestreo, no se encontró una situación de contaminación por petróleo en los ecosistemas costeros estudiados, puesto que las concentraciones de HPDD no rebasaron el límite de 10 µg·L-1 referido a equivalentes de criseno, considerado típico de áreas oceánicas contaminadas. En Bahía Culebra fue la primera vez que se hizo el estudio de la contaminación por petróleo y se comprobó que en las fechas de muestreo la zona estuvo libre de esta contaminación. El promedio y la desviación estándar en el Estero de Puntarenas fueron 1.21 µg·L-1 ± 2.10 µg·L-1 (n = 7), en un ámbito de 0.17 a 5.91 µg·L-1. Estos resultados evidenciaron una situación de contaminación moderada y la naturaleza estuarina de este cuerpo de agua costera, que distribuye irregularmente los HPDD descargados en ella

Four coastal ecosystems with contrasting characteristics were sampled in Costa Rica (2000 – 2002). Oil pollution status, expressed as the fraction of dissolved/dispersed petroleum hydrocarbons related to chrysene equivalents, was determined by the molecular fluorescence analytical technique. A total of 130 water samples were taken, from the Caribbean (Moín Bay), and from the Pacific (Bahía Culebra, Gulf of Nicoya and Dulce Gulf). On one occasion, seven samples along the Puntarenas estuary were also analysed. In Moín the mean and standard deviation were 0.10 µg·L-1 ± 0.18 µg·L-1, ranging from non detectable (nd) to 0.65 µg·L-1. For the Pacific ecosystems the total range was from nd to 0.37 µg·L-1. In Bahía Culebra no fluorescence signals were obtained. In the Gulf of Nicoya the mean and standard deviation were 0.04 µg·L-1 ± 0.09 µg·L-1, from nd to 0.33 µg·L-1. Values in Dulce Gulf were 0.05 µg·L-1 ± 0.11 µg·L-1, from nd to 0.37 µg·L-1. Along the Puntarenas estuary the range was 0.17 to 5.91 µg·L-1, with a mean of 1.21 µg·L-1 and a standard deviation of ± 2.10 µg·L-1. The four coastal ecosystems had concentrations below the 10 µg·L-1 limit for polluted oceanic areas. The Puntarenas estuary reflects the influence of antropogenic activities from and around the City of Puntarenas. These levels are considered low for inshore waters

A new procedure for treatment of oily slurry using geotextile filters.

A new procedure to mitigate the environmental impacts and reduce the cost of disposal of oil slurry is present in this paper. Waste from the petroleum industry has a high environmental impact. Systems for oil-water separation have been used to mitigate the contamination potential of these types of effluents. At the outlet of these systems, the oil is skimmed-off the surface, while the slurry is removed from the base. Due to the high concentration of contaminants, the disposal of this slurry is an environmentally hazardous practice. Usually this type of waste is disposed of in tanks or landfills after removal from the industrial plant. Basically, the proposed procedure utilizes drying beds with geotextile filters to both reduce the water content in the slurry and obtain a less contaminated effluent. Laboratory tests were carried out to simulate the drying system. Four types of filters were analyzed: two non-woven geotextiles, one woven geotextile, and a sand filter.

Oil spills debris clean up by thermal desorption.

Oil spills represent a significant environmental issue in Brazil. This paper presents the latest results of a comprehensive experimental programme aimed at understanding how the presence of spilled oil affects the properties of sands and at studying alternatives to remediate the affected shores. Results indicate that oil causes a slight increase in grain size and uniformity, and oiled debris presents a smaller void ratio but a larger unit weight. It was also observed that effective strength parameters for both the natural and oiled debris were the same although the undrained strength of a natural sand is much higher than that of the contaminated sand. At ambient temperature, oiled debris emits methane and ammonia, and these emissions tend to increase with rising temperatures. On the other hand, the oil and grease content from oiled debris decreases with rising temperature and prolonged exposure. Finally, in situ thermal desorption seems to be a promising method for cleaning debris from oil spills. It is simple, fast and avoids all the difficulties associated with digging up the soil for disposal or cleanup.

[Oil pollution status expressed as the fraction of dissolved and dispersed petroleum hydrocarbons]. / Hidrocarburos de petróleo, disueltos y dispersos, en cuatro ambientes costeros de Costa Rica.

Four coastal ecosystems with contrasting characteristics were sampled in Costa Rica (2000-2002). Oil pollution status, expressed as the fraction of dissolved/dispersed petroleum hydrocarbons related to chrysene equivalents, was determined by the molecular fluorescence analytical technique. A total of 130 water samples were taken, from the Caribbean (Moín Bay), and from the Pacific (Bahía Culebra, Gulf of Nicoya and Dulce Gulf). On one occasion, seven samples along the Puntarenas estuary were also analysed. In Moín the mean and standard deviation were 0.10 microg x L(-1) +/- 0.18 micro x L(-1), ranging from non detectable (nd) to 0.65 microg x L(-1). For the Pacific ecosystems the total range was from nd to 0.37 microg x L(-1). In Bahia Culebra no fluorescence signals were obtained. In the Gulf of Nicoya the mean and standard deviation were 0.04 microg x L(-1) +/- 0.09 microg x L(-1), from nd to 0.33 microg x L(-1). Values in Dulce Gulf were 0.05 microg x L(-1) +/- 0.11 microg x L(-1), from nd to 0.37 microg x L(-1). Along the Puntarenas estuary the range was 0.17 to 5.91 microg x L(-1), with a mean of 1.21 microg x L(-1) and a standard deviation of +/- 2.10 microg x L(-1). The four coastal ecosystems had concentrations below the 10 microg x L(-1) limit for polluted oceanic areas. The Puntarenas estuary reflects the influence of antropogenic activities from and around the City of Puntarenas. These levels are considered low for inshore waters.

Evaluación del ambiente aledaño a un expendio de combustible dentro del Parque Nacional Morrocoy, Venezuela. II: Calidad de aguas, sedimentos y biota / Environmental evaluation near to a fuel vendor inside of the Parque Nacional Morrocoy, Venezuela. II: Water quality, sediments and biota

This paper is the second part of a base line study carried out in the coastal region near a marine service station located in Morrocoy National Park, Venezuela. Results from a physical and chemical characterization of the water and sediments of four sites located around the service station are presented. The physical and chemical factors measured in water included: temperature, salinity, specific conductance, dissolved oxygen, saturation percentage of dissolved oxygen, pH, total suspended solids, transparency, oil and grease, total residual petroleum hydrocarbon, vanadium and lead, total coliform bacteria, and the presence of coliform bacteria. The factors measured in sediments include: granulometry, organic material, total carbonates, vanadium, lead, oil and grease, and total hydrocarbons. In addition, the amount of vanadium and lead in sample tissue from three species which are abundant and widely distributed in each site was measured in order to evaluate the potential of these species as bio-indicators. The water in the area where this study was conducted is shallow, warm, and thermally homogeneous, with high salinity and normal pH and dissolved oxygen, and supersaturated with oxygen in certain hours in sites adjacent to abundant underwater vegetation. The water is moderately turbid with a tendency towards less dissolved oxygen with increased depth. The estimated values of NMP/100 ml of the coliform fecal organisms is within legal limits even though the total number of water coliforms measured in Site 2 was ten times higher than in Site 1. This increase is associated with the proximity of Site 2 to an outflow of pre-treated sewage. The values of TRPH in the water collected from each site were low and very close to the detection limit (0.8/ml). Vanadium was not found, while lead was detected in 11 of the 12 samples. Compared to the values measured for Site 1, which was the local reference, only one sample had a concentration of three times the maximum...

[Environmental evaluation near a fuel vendor within Parque Nacional Morrocoy, Venezuela. II: Water quality, sediments and biota]. / Evaluación del ambiente aledaño a un expendio de combustible dentro del Parque Nacional Morrocoy, Venezuela. II: Calidad de aguas, sedimentos y biota.

This paper is the second part of a base line study carried out in the coastal region near a marine service station located in Morrocoy National Park, Venezuela. Results from a physical and chemical characterization of the water and sediments of four sites located around the service station are presented. The physical and chemical factors measured in water included: temperature, salinity, specific conductance, dissolved oxygen, saturation percentage of dissolved oxygen, pH, total suspended solids, transparency, oil and grease, total residual petroleum hydrocarbon, vanadium and lead, total coliform bacteria, and the presence of coliform bacteria. The factors measured in sediments include: granulometry, organic material, total carbonates, vanadium, lead, oil and grease, and total hydrocarbons. In addition, the amount of vanadium and lead in sample tissue from three species which are abundant and widely distributed in each site was measured in order to evaluate the potential of these species as bio-indicators. The water in the area where this study was conducted is shallow, warm, and thermally homogeneous, with high salinity and normal pH and dissolved oxygen, and supersaturated with oxygen in certain hours in sites adjacent to abundant underwater vegetation. The water is moderately turbid with a tendency towards less dissolved oxygen with increased depth. The estimated values of NMP/100 ml of the coliform fecal organisms is within legal limits even though the total number of water coliforms measured in Site 2 was ten times higher than in Site 1. This increase is associated with the proximity of Site 2 to an outflow of pre-treated sewage. The values of TRPH in the water collected from each site were low and very close to the detection limit (0.8/ml). Vanadium was not found, while lead was detected in 11 of the 12 samples. Compared to the values measured for Site 1, which was the local reference, only one sample had a concentration of three times the maximum baseline. The amount of lead found in all analyzed samples was acceptable, according to the standards set by the State of Washington (maximum value: 292 mg/kg), while the concentration of lead in the sediments around the supply dock were 1.5 to 3.4 times greater than the Dutch norm. It can be concluded that there is no evidence of an accumulation of Va or Pb in the species selected as bioindicators. An observation program is proposed in which variables similar to those measured for this characterization will be studied with some modifications. A more intense sampling of some variables is recommended (lead in water and sediments, total coliform and fecal matter in consecutive samples and in days following a high concentration of visitors) as is the elimination or minimization of other variables.