ABSTRACT
The effects of asphaltenes on the photolytic and toxic behavior of petroleum oil on seawater was investigated by exposing five original oils and their maltenes to solar irradiation for seven days. Polycyclic aromatic hydrocarbons (PAHs) experienced the fastest photo-oxidation, but negligible photolytic loss was observed for most normal alkanes and all the petroleum biomarkers from tri-cyclic to pentyl-cyclic terpanes in the test total oil and maltenes. The removal of most PAHs from some maltenes was greater than the corresponding total oils. Deasphalting process did not affect the characteristics of naphthenic acid fraction components (NAFCs) in all control samples. In all test oils, solar irradiation formed abundant NAFCs, in particular those only containing oxygen as the heteroatoms (Oo species). The formed Oo species were abundant in congeners having highly saturated congeners, and shifted to a lighter carbon number after exposed. Deasphalting process significantly enhanced the formation of Oo species (o from 2 to 4) for all test oils, in particular for the Cold Lake Blend and Bunker C. The toxicity of exposed maltenes was generally higher than the exposed total oil for most oils, suggesting the aqueous toxicity level was positively related to the formed NAFC intermediates.
Subject(s)
Petroleum Pollution , Petroleum , Polycyclic Aromatic Hydrocarbons , Water Pollutants, Chemical , Hydrocarbons/toxicity , Oils , Petroleum/analysis , Petroleum/toxicity , Petroleum Pollution/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicityABSTRACT
In this study, the water accommodated and particle-laden hydrocarbon species, and the toxicity of the aqueous phase after oil-sediment interactions by varying the weathering states of diluted bitumen (Cold Lake blend (CLB)), oil type from light to heavy, and sediment type. Compared to the original oils, the sediment-laden total petroleum hydrocarbons (TPH) contained fewer hydrocarbons in the carbon range
Subject(s)
Hydrocarbons/chemistry , Petroleum Pollution , Petroleum/analysis , Water Pollutants, Chemical/analysis , Alberta , Hydrocarbons/toxicity , Lakes , Oils , Petroleum/toxicity , Polycyclic Aromatic Hydrocarbons , Water/chemistry , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/toxicity , WeatherABSTRACT
Transcriptomic analysis can complement traditional ecotoxicology data by providing mechanistic insight, and by identifying sub-lethal organismal responses and contaminant classes underlying observed toxicity. Before transcriptomic information can be used in monitoring and risk assessment, it is necessary to determine its reproducibility and detect key steps impacting the reliable identification of differentially expressed genes. A custom 15K-probe microarray was used to conduct transcriptomics analyses across six laboratories with estuarine amphipods exposed to cyfluthrin-spiked or control sediments (10 days). Two sample types were generated, one consisted of total RNA extracts (Ex) from exposed and control samples (extracted by one laboratory) and the other consisted of exposed and control whole body amphipods (WB) from which each laboratory extracted RNA. Our findings indicate that gene expression microarray results are repeatable. Differentially expressed data had a higher degree of repeatability across all laboratories in samples with similar RNA quality (Ex) when compared to WB samples with more variable RNA quality. Despite such variability a subset of genes were consistently identified as differentially expressed across all laboratories and sample types. We found that the differences among the individual laboratory results can be attributed to several factors including RNA quality and technical expertise, but the overall results can be improved by following consistent protocols and with appropriate training.
Subject(s)
Ecotoxicology/standards , Gene Expression Profiling/methods , Laboratories/standards , Oligonucleotide Array Sequence Analysis/methods , Toxicogenetics/standards , Amphipoda/drug effects , Amphipoda/genetics , Animals , Gene Expression Profiling/standards , Geologic Sediments/chemistry , Humans , Nitriles/toxicity , Oligonucleotide Array Sequence Analysis/standards , Pyrethrins/toxicity , Reproducibility of ResultsABSTRACT
Agricultural pesticide runoff has been suspected as the cause of numerous fish kills in rivers throughout Prince Edward Island but the impact on the surrounding marine environment is unknown. Endosulfan, an organochlorine pesticide, is a potent neurotoxin and molt inhibitor used to combat the Colorado potato beetle however it has the potential to affect non-target organisms including the American lobster (Homarus americanus). Metamorphosis is a critical stage of development and the effects of contaminant exposure during this time are largely unknown in lobster. A 14day endosulfan exposure was performed to identify the effects on survival, development and gene expression in lobster larvae during metamorphosis; all of which were predicted to be negatively impacted. The higher endosulfan concentrations resulted in greater mortality and a significant increase in the number of days required to reach metamorphosis in surviving animals. A custom made H. americanus microarray was used for monitoring the changes in expression of 14,592 genes at the termination of the exposure. Genes with >1.5 fold change and identified as being significant at p<0.05 using one-way ANOVA were selected for further analysis. A total of 707 genes were identified as being significantly differentiated, however with only ~40% annotation of the array, the majority of these genes were unknown. Annotated genes of interest were involved in many processes: development, metabolism, immunity and oxidative stress response and gene regulation. Nine genes of interest (histone H1, farnesoic acid O-methyltransferase, cuticle protein, glutathione S-transferase, thioredoxin, NADH dehydrogenase, ecdysone nuclear receptor Fushi tarazu F1 (FTZ-F1), ferritin and ecdysone inducible protein E75 (EIP-E75)) were selected for RT-qPCR validation of the microarray results. The RT-qPCR method was more sensitive than the microarray yet detected similar expression patterns. The two highest endosulfan concentrations resulted in increased mortalities, developmental delays in reaching metamorphosis and significant changes in gene expression. This research provides a foundation for using microarray gene expression profiles as screening tools for exploring the impact of environmental contaminants on lobster.
Subject(s)
Endosulfan/toxicity , Metamorphosis, Biological/drug effects , Nephropidae/genetics , Animals , Gene Expression Regulation, Developmental , Larva/drug effects , Molecular Sequence Annotation , Nephropidae/metabolism , Protein Array Analysis , Transcriptome/drug effects , Water Pollution, ChemicalABSTRACT
Comparative toxicity testing was performed on selected materials that may be used in aquatic construction projects. The tests were conducted on the following materials: (1) untreated wood species (hemlock [Tsuga ssp], Western red cedar (Thuja plicata), red oak [Quercus rubra], Douglas fir [Pseudotsuga menziesii], red pine [Pinus resinosa], and tamarack [Larix ssp]); (2) plastic wood; (3) Ecothermo wood hemlock stakes treated with preservatives (e.g., chromated copper arsenate [CCA], creosote, alkaline copper quaternary [ACQ], zinc naphthenate, copper naphthenate, and Lifetime Wood Treatment); (4) epoxy-coated steel; (5) hot-rolled steel; (6) zinc-coated steel; and (7) concrete. Those materials were used in acute lethality tests with rainbow trout, Daphnia magna, Vibrio fischeri and threespine stickleback. The results indicated the following general ranking of the materials (from the lowest to highest LC(50) values); ACQ > creosote > zinc naphthenate > copper naphthenate > CCA (treated at 22.4 kg/m(3)) > concrete > red pine > western red cedar > red oak > zinc-coated steel > epoxy-coated steel > CCA (6.4 kg/m(3)). Furthermore, the toxicity results indicated that plastic wood, certain untreated wood species (hemlock, tamarack, Douglas fir, and red oak), hot-rolled steel, Ecothermo wood, and wood treated with Lifetime Wood Treatment were generally nontoxic to the test species.
Subject(s)
Construction Materials/toxicity , Toxicity Tests/methods , Wood/chemistry , Aliivibrio fischeri/drug effects , Animals , Arsenates/analysis , Arsenates/toxicity , Carboxylic Acids/analysis , Carboxylic Acids/toxicity , Creosote/analysis , Creosote/toxicity , Daphnia/drug effects , Environmental Monitoring/methods , Larix/chemistry , Pinus/chemistry , Plastics/analysis , Plastics/toxicity , Pseudotsuga/chemistry , Quercus/chemistry , Thuja/chemistry , Tsuga/chemistry , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicityABSTRACT
BACKGROUND: It is well known that many anurans do not reproduce easily in captivity. Some methods are based on administration of mammalian hormones such as human chorionic gonadotropin, which are not effective in many frogs. There is a need for simple, cost-effective alternative techniques to induce spawning. METHODS: Our new method is based on the injection of a combination of a gonadotropin-releasing hormone (GnRH) agonist and a dopamine antagonist. We have named this formulation AMPHIPLEX, which is derived from the combination of the words amphibian and amplexus. This name refers to the specific reproductive behavior of frogs when the male mounts and clasps the female to induce ovulation and to fertilize the eggs as they are laid. RESULTS: We describe the use of the method and demonstrate its applicability for captive breeding in 3 different anuran families. We tested several combinations of GnRH agonists with dopamine antagonists using Lithobates pipiens. The combination of des-Gly10, D-Ala6, Pro-LHRH (0.4 microrams/g body weight) and metoclopramide (10 micrograms/g BWt. MET) was most effective. It was used in-season, after short-term captivity and in frogs artificially hibernated under laboratory conditions. The AMPHIPLEX method was also effective in 3 Argentinian frogs, Ceratophrys ornata, Ceratophrys cranwelli and Odontophrynus americanus. CONCLUSION: Our approach offers some advantages over other hormonally-based techniques. Both sexes are injected only once and at the same time, reducing handling stress. AMPHIPLEX is a new reproductive management tool for captive breeding in Anura.
Subject(s)
Anura/physiology , Dopamine Antagonists/administration & dosage , Gonadotropin-Releasing Hormone/agonists , Ovulation Induction/methods , Animals , Dopamine Antagonists/pharmacology , Drug Combinations , Female , Gonadotropin-Releasing Hormone/administration & dosage , Gonadotropin-Releasing Hormone/analogs & derivatives , Gonadotropin-Releasing Hormone/pharmacology , Injections , Male , Metoclopramide/administration & dosage , Metoclopramide/pharmacology , Ovulation Induction/veterinary , Seasons , Species SpecificityABSTRACT
There are over 1100 fish-processing plants in Canada and the majority of them discharge untreated effluents directly to marine or estuarine receiving environments. The purpose of this study was to evaluate chemical and toxicological characteristics of sediments near fish-processing plant effluent discharges to assess potential impacts of seafood-processing effluents on receiving environments. Eighteen sediment samples were collected near effluent discharges of six seafood-processing plant outfalls in New Brunswick, Canada in the winter of 2006. Ammonia levels ranged from <0.2 to 3480 microg/g, sulfide levels ranged from <0.4 to 6970 microg/g, and redox ranged from -255 to 443 mV. Only one sample had a Microtox Solid-Phase Test IC(50) value below 1000 mg/kg, whereas three samples caused greater than 30% reduction to amphipod survival. Redox, sulfide, and ammonia concentrations were all found to be significantly related to both Eohaustorius estuarius survival and Microto (Vibrio fischeri) IC(50). An increase in sulfide (R (2) = 0.584; 0.750) and ammonia (R (2) = 0.478; 0.552) and a decrease in redox (R (2) = 0.485; 0.651) were associated with an increase in toxicity to E. estuarius and Microtox, respectively. The highest toxicity to both test organisms, and the most contaminated sediments based on physical/chemical characteristics measured, was observed in samples from Blacks Harbour.
Subject(s)
Food-Processing Industry , Geologic Sediments/analysis , Industrial Waste/adverse effects , Seafood , Water Pollutants, Chemical/toxicity , Ammonia/analysis , Ammonia/toxicity , Animals , Industrial Waste/analysis , Lethal Dose 50 , Regression Analysis , Sulfides/analysis , Sulfides/toxicity , Toxicity Tests , Water Pollutants, Chemical/analysisABSTRACT
Pesticides sprayed on farmlands can end up in rivers and be transported into estuaries, where they could affect aquatic organisms in freshwater and marine habitats. A series of experiments were conducted using the amphipod Corophium volutator Pallas (Amphipoda, Corophiidae) and single pesticides, namely atrazine (AT), azinphos-methyl (AZ), carbofuran (CA) and endosulfan (EN) that were added to sediments and covered with seawater. Our goal was to compare the concentrations affecting the survival of the animals relative to potential attractant or repellent properties of sediment-spiked pesticides. The avoidance/preference of contaminated/reference sediments by amphipods was examined after 48 and 96 h of exposure using sediments with different organic carbon content. The octanol-water partition coefficients (log K(ow)) ranked the pesticides binding to sediments as EN > AZ > AT > CA. LC(50) and LC(20) covered a wide range of nominal concentrations and ranked toxicity as CA-AZ > EN > AT. Under the experimental set up, only EN initiated an avoidance response and the organic carbon normalised concentration provided consistent results. Using the present data with wide confidence limits, >20% of a population of C. volutator could perish due to the presence of EN before relocation or detecting CA or AZ in sediments by chemical analysis.
Subject(s)
Amphipoda/drug effects , Behavior, Animal/drug effects , Pesticides/toxicity , Water Pollutants, Chemical/toxicity , Animals , Atrazine/analysis , Atrazine/chemistry , Atrazine/toxicity , Azinphosmethyl/analysis , Azinphosmethyl/chemistry , Azinphosmethyl/toxicity , Carbofuran/analysis , Carbofuran/chemistry , Carbofuran/toxicity , Carbon/chemistry , Endosulfan/analysis , Endosulfan/chemistry , Endosulfan/toxicity , Environmental Monitoring , Geologic Sediments/analysis , Lethal Dose 50 , Pesticides/analysis , Pesticides/chemistry , Seawater/chemistry , Time Factors , Water Pollutants, Chemical/analysisABSTRACT
The potential ecological impacts of anaerobic degradation of vegetable oil on freshwater sediments were investigated. Sediment toxicity was evaluated using two regulatory biotests: the Microtox Solid Phase Test and an amphipod (Hyalella azteca) bioassay. The results of the Microtox test showed that the toxicity of the vegetable-oil-contaminated sediments (about 17-33 g oil/kg dry sediments) increased after 2 weeks incubation and then decreased to near background levels after incubation for 8 weeks under anaerobic conditions. The amphipod toxicity bioassay showed that the toxicity of fresh contaminated sediments decreased over time and returned to background levels within 8 weeks. These results suggest that the impact of vegetable oils on organisms within sediments may be limited. To account for the significance of environmental conditions, additional studies over a wide range of incubation conditions (e.g., temperature, nutrient concentration) and other test organisms at various trophic levels are recommended for both acute and chronic toxicity assessment.
Subject(s)
Amphipoda/drug effects , Geologic Sediments/chemistry , Plant Oils/metabolism , Toxicity Tests/methods , Water Pollutants, Chemical/toxicity , Amphipoda/metabolism , Anaerobiosis , Animals , Biodegradation, Environmental , Biological Assay , Food Chain , Fresh Water , Risk Assessment , Temperature , Time FactorsABSTRACT
Ten acidic and two neutral pharmaceuticals were detected in the effluents of eight sewage treatment plants (STPs) from across Atlantic Canada. Concentrations varied between nondetectable and 35 microg/L. The analgesic, nonsteroidal anti-inflammatory drugs ibuprofen and naproxen were predominant. Carbamazepine, a neutral compound used as an antiepileptic drug, was observed consistently at a median concentration of 79 ng/L. Acetaminophen was found in the effluents of the three largest mechanical STPs at a median concentration of 1.9 microg/L, but not in the lagoon treatment systems. The substantially longer hydraulic retention times may have contributed to more effective removal of acetaminophen in the lagoon treatment systems. Drugs generally were not detected at significant concentrations in the larger bodies of receiving water (Saint John River, Hillsborough River, and Bedford Bay, Canada). However, drug residues in the small receiving streams were 15 to 30% of the effluent median concentrations. Six compounds (caffeine, naproxen, salicylic acid, carbamazepine, metoprolol, and sotolol) were found to persist in a small stream for a distance of at least 17 km, suggesting that small stream exposure to pharmaceutically active residues may be relatively greater than that in large bodies of water. Bioassays assessing acute and chronic effects on four organisms were conducted on four high-use drugs: Acetaminophen, ibuprofen, naproxen, and salicylic acid (metabolite of acetyl salicylic acid). Results indicated no negative effects except for the chronic algal (Selanastrum capricornutum) growth test on ibuprofen (no-observed-effect concentration, 10 microg/L; lowest-observed-effect concentration, 32 microg/L). Effects of these four compounds on invertebrates and plants in the receiving environments are unlikely based on the concentrations measured.
Subject(s)
Pharmaceutical Preparations/analysis , Sewage , Water Pollutants, Chemical/toxicity , Canada , Chromatography, High Pressure Liquid , Mass Spectrometry , Water Pollutants, Chemical/analysisABSTRACT
Sediments in Sydney Harbour, Nova Scotia, are highly contaminated by polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and heavy metals. Histopathologic and histochemical evaluations were made on the Baltic clam, Macoma balthica, exposed to 11 Sydney Harbour sediment samples. Histologic lesions in digestive gland (tubular dilation or atrophy, macrophage aggregates, tubular cell necrosis, and tissue inflammation) and gonads (macrophage aggregates, supporting cell, germ cell, and ovarian cell necroses) were frequently detected in clams exposed to the most contaminated sediments from the harbor. Clams exposed to these contaminated sediments also had the highest acid phosphatase activity. The average scores of tubular dilation or atrophy, ovarian cell necrosis, and the sums of mean digestive gland lesions correlated significantly with sediment PCBs, and the activities of acid phosphatase correlated significantly with sediment heavy metals, PAHs, and PCBs. Among the lesions, digestive gland tubular dilation or atrophy, tubular cell, germ cell, and ovarian cell necroses, and the activity of acid phosphatase are the best sublethal effect indicators in Macoma exposed to Sydney Harbour sediments. Key words: biomarkers, chronic biologic effects, clams, histology, histochemistry, Macoma balthica, marine sediment, polynuclear aromatic hydrocarbons, polychlorinated biphenyls.