原油WSF对三种海洋鱼类肝微粒体EROD活性的诱导和恢复的比较

研究了实验室条件下原油水溶性组分(WSF)暴露对黑鲷、黄鳍鲷和褐菖鲉肝微粒体EROD活性的剂量-效应,时间-效应和恢复过程。实验结果表明,在剂量诱导实验中,褐菖鲉肝EROD活性在原油WSF浓度为50 μg/dm³时呈现生物统计学上的显著差异,而黑鲷和黄鳍鲷肝EROD活性在75 μg/dm³时才呈现生物统计学上的显著差异;褐菖鲉肝EROD活性诱导倍数最高,但黑鲷的诱导浓度范围较广。在时间诱导实验中, 在40 μg/dm³原油WSF暴露下黄鳍鲷肝EROD活性在2 d时首先呈现显著差异; 三种鱼肝EROD活性均在第4天达到最高,并呈现显著性变化,此后随着暴露时间的延长而逐渐下降并接近对照组水平。在恢复实验中三种鱼肝EROD活性下降并恢复到对照组水平。研究结果表明:对于石油污染物,黑鲷、黄鳍鲷和褐菖鲉肝EROD活性都可以作为污染生化效应监测指标,然而就三种鱼类比较而言,褐菖鲉最敏感,更适合于作为石油类污染及其生化效应,尤其是低剂量效应的监测生物。     

原油WSF对三种海洋鱼类肝微粒体EROD活性的诱导和恢复的比较

研究了实验室条件下原油水溶性组分(WSF)暴露对黑鲷、黄鳍鲷和褐菖鲉肝微粒体EROD活性的剂量-效应,时间-效应和恢复过程。实验结果表明,在剂量诱导实验中,褐菖鲉肝EROD活性在原油WSF浓度为50μg/dm3时呈现生物统计学上的显著差异,而黑鲷和黄鳍鲷肝EROD活性在75μg/dm3时才呈现生物统计学上的显著差异;褐菖鲉肝EROD活性诱导倍数最高,但黑鲷的诱导浓度范围较广。在时间诱导实验中,在40μg/dm3原油WSF暴露下黄鳍鲷肝EROD活性在2 d时首先呈现显著差异;三种鱼肝EROD活性均在第4天达到最高,并呈现显著性变化,此后随着暴露时间的延长而逐渐下降并接近对照组水平。在恢复实验中三种鱼肝EROD活性下降并恢复到对照组水平。研究结果表明:对于石油污染物,黑鲷、黄鳍鲷和褐菖鲉肝EROD活性都可以作为污染生化效应监测指标,然而就三种鱼类比较而言,褐菖鲉最敏感,更适合于作为石油类污染及其生化效应,尤其是低剂量效应的监测生物。     

Acute sublethal toxicity of MV Rena contaminants (heavy fuel oil,oil dispersant and cryolite) to finfish and rock lobster

ABSTRACT

The wreck of the MV Rena in October 2011 discharged large quantities of potentially toxic materials in the coastal marine environment of the Bay of Plenty, New Zealand. We evaluated sublethal effects of the water soluble fractions of physically and chemically dispersed heavy fuel oil (HFO) and the water soluble fraction of cryolite on the haematology of subadult or adult snapper (Chrysophrys auratus), spotted wrasse (Notolabrus celidotus) and red rock lobster (Jasus edwardsii). Small but transient effects occurred, the most significant of which were changes in circulating immune cell populations in fish and lobster that recovered by the conclusion of a 96-h exposure period. No post-exposure effects were observed during a 10-day recovery in toxicant-free seawater. Corexit 9500 oil dispersant increased polycyclic aromatic hydrocarbon (PAH) uptake from HFO in fish and lobster by around two-fold and four-fold, respectively, and caused a larger change in immune cell abundance in snapper than exposure to HFO alone. While depuration of PAHs was more rapid in fish than lobster, significantly elevated PAH levels were still evident after 10 days of depuration.     

The effects of bunker c oil and an oil dispersant: Part 2—effects on the accumulation of chlorine-labelled bunker c oil in various fish tissues

Chlorine-labelled Bunker C oil was used to measure the differential accumulation in various fish tissues between a hydrocarbon and a hydrocarbon/oil dispersant mixture. There is an increased movement of the emulsified oil across the gill structure although accumulation by this tissue is similar for both test conditions. The liver and kidney showed significantly higher levels of the oil/dispersant mixture whereas muscle accumulations were less dramatic. The amounts of Bunker C found in the gills, liver and kidney were considerably higher than that found in the muscle. Consideration was given to the varying capability of the blood to carry polar, compared with non-polar, compounds.     

Metabolic effects and hydrocarbon fate in arctic bivalves exposed to dispersed petroleum

A number of experiments were carried out in the Canadian Arctic on Baffin Island with the purpose of defining the short- and long-term effects of exposure to dispersed crude oil on marine benthic invertebrates. The study reported here assessed metabolic responses by physiological and biochemical indices, and evaluated these in relation to exposure concentration. The overall objective of the study was to evaluate the potential for long-term survival of benthic communities in the Arctic following an oil spill. This objective was consistent with the goals of the larger Baffin Island Oil Spill (BIOS) program, which was implemented to evaluate the relative mitigating effectiveness of chemical dispersants, as compared to conventional oil spill counter-measures.     

Impact of laboratory exposure to light Arabian crude oil,dispersed oil and dispersant on the gills of the juvenile brown spotted grouper (Epinephelus chlorostigma): A histopathological study

The present study investigated the impact of subchronic exposure of the water accommodated fraction (WAF) of light Arabian crude oil, dispersed oil and dispersant on the gills of the juvenile brown spotted grouper (Epinephelus chlorostigma), observing several histopathological lesions at different time points and different concentrations. Significant alterations, compared to the control groups (p < 0.05), in four health categories (circulatory, proliferative, degenerative and inflammatory) were identified. Evaluations of histopathological lesions in gill tissue were carried out following 3, 6, 9, 12, 15, 18 and 21 days of exposure. The main lesions observed were circulatory (lamellar aneurysms, vasodilatation and hemorrhage), degenerative (edema, lifting of lamellar and filamentary epithelium and epithelium necrosis), proliferative (hypertrophy and hyperplasia of epithelial, mucous and chloride cells, fusion of adjacent lamellae), and inflammatory (lymphocytic infiltration). These results provide a tool for evaluating reclamation initiatives, such as the use of dispersants, and lead to better risk evaluations and environmental health in natural and reclaimed systems.     

Physiological responses of a marine fish exposed to chlorinated seawater at concentrations near its avoidance threshold

To determine if avoidance of chlorinated seawater by fish resulted in physiological protection from toxicity, studies were carried out which assessed (a) changes in the routine oxygen consumption rate and (b) the ability of treated fish to successfully compete with untreated conspecifics for a limited food resource.Temperate marine damselfish, Chromis punctipinnis, were exposed to stepwise increasing levels of chlorinated seawater in a behaviour chamber and avoided total residual oxidant (TRO) levels greater than 0·15-0·16 mg/litre. Cumulative exposures ranged from the equivalent of 0·38-5·23 in at 1·0/litre TRO. One day after exposure, routine oxygen consumption rates were decreased by 25 to 45% from pre-exposure rates and were correlated with the cumulative oxidant exposure. One month post exposure, respiration rates returned to pre-treatment levels. This transient depression of the respiratory rate did not affect survival or growth of chlorine-treated fish which were forced to compete with untreated conspecifics for a restricted food supply.     

Induction of heat shock protein (hsp)60 in Isochrysis galbana exposed to sublethal preparations of dispersant and Prudhoe Bay crude oil

Adaptation to sublethal exposure to crude oil by phytoplankton is poorly understood. Use of chemical dispersants for oil spill remediation increases petroleum hydrocarbon concentrations in water, while exposing marine organisms to potentially toxic concentrations of dispersant. Heat shock proteins (hsps) have been found to serve as an adaptive and protective mechanism against environmental stresses. The objective of this project was to examine the induction of hsps in Isochrysis galbana, a golden-brown algae, following exposure to the water-accommodated fraction (WAF) of Prudhoe Bay crude oil (PBCO) and PBCO chemically dispersed with Corexit 9527® (dispersed oil: DO). Initial experiments using ³⁵S-labeled amino acids and 2-dimensional electrophoresis with subsequent western blotting identified and confirmed hsp60, a member of the chaperonin family of stress proteins, as being efficiently induced by heat shock in this species. One-dimensional SDS PAGE and western blotting, with hsp60 antibodies and chemiluminesence detection, were used to quantitate hsp60 following exposure to a range of environmental temperatures and concentrations of WAF and DO preparations. I. galbana cultured in 22 parts per thousand (‰) salinity showed a statistically significant increase (p<0.05) in hsp60 after exposure to 25, 30, and 35°C for 1 h compared to controls (20°C), while 34‰ cultures showed no significant increase in hsp60 with increasing temperature. Cultures (22 and 34‰) exposed to varying doses of WAF and DO exhibited statistically significant (p<0.05) increases in levels of hsp60 in all cases. A dose-related response was observed in all exposures (r²≥0.90) with the exception of 34‰ WAF. In independent exposures, a dose-related hsp60 response to naphthalene, a relatively abundant water-soluble aromatic hydrocarbon, was observed in both 22 and 34‰ cultures. Results of this study are consistent with previous studies in other species documenting increases in hsp60 levels with exposure to xenobiotics. Further studies are investigating the protective function of hsp60 against the toxic effects of exposure to WAF and DO preparations.     

Investigation of effects of environmental xenobiotics to fish at sublethal levels by molecular biological approaches

In recent years, there has been increasing concern as to the potential health effects of polyhalogenated and/or polynuclear aromatic hydrocarbons, since these environmental xenobiotics have been associated with reproductive dysfunction in a variety of wildlife. Studies are described here on the development of molecular biological parameters for: (i) the investigation of toxic mechanisms of environmental xenobiotics at sublethal levels; and (ii) the screening of any other toxic chemical pollutants in the aquatic ecosystems. Through molecular cloning, cDNA of estrogen-responsive genes and growth hormone gene of rainbow trout have been isolated. In appropriate rainbow trout primary or established cell culture systems, these cDNA clones can be used as molecular probes for the elucidation of molecular toxic mechanisms of environmental xenobiotics.     

Water temperature interacts with the insecticide imidacloprid to alter acute lethal and sublethal toxicity to mayfly larvae

ABSTRACT

Increased temperatures and exposure to agricultural insecticides are increasingly threatening freshwater ecosystems worldwide. However, their combined effects are still poorly understood. We investigated the individual and interactive effects of water temperature and imidacloprid, the most widely used neonicotinoid insecticide, on larvae of two New Zealand mayflies, Deleatidium spp. and Coloburiscus humeralis. Ninety-six-hour bioassays with imidacloprid were performed at 9, 12, 15, 18, 21 and 24°C, in a full-factorial design. Mayfly survivorship and sub-lethal responses of impairment and moulting were recorded. We documented synergistically increased mayfly mortality and immobility with exposure to imidacloprid at higher temperatures, implying temperature-enhanced toxicity of imidacloprid. Survivorship of both mayflies was synergistically reduced by the combination of imidacloprid exposure and increasing temperatures. The same interaction also affected mobility of C. humeralis and moulting frequency of Deleatidium. Our findings suggest that developing a more thorough understanding of temperature-contaminant interactions may be important to allow better protection of aquatic ecosystems.     

A comparison of the levels of hepatic aryl hydrocarbon hydroxylase in fish caught close to and distant from north sea oil fields

Large-scale use of oil-based muds for drilling operations offshore can lead to high concentrations of aromatic hydrocarbons in the sediments close to these platforms. Fish were trawled from stations close to and distant from such platforms and the levels of hepatic aryl hydrocarbon hydroxylase (AHH) were determined in cod, haddock and whiting. These three species were caught in sufficient numbers to make reasonable preliminary data sets. The data for cod and haddock showed significantly higher levels of AHH in the livers of fish caught close to oil platforms than in those caught in areas away from oil activity, while whiting showed no such differences. A much larger sample number together with some measurement of enhanced cytochrome P-450 levels would be required to substantiate this trend, but these data are the first indications that the oil in the sediments around platforms may be biochemically available to fish in the area.     

Evaluation of the relationships between biochemical endpoints of PAH exposure and physiological endpoints of reproduction in male California Halibut (Paralichthys californicus) exposed to sediments from a natural oil seep

Coal Oil Point (COP) is a natural oil seep off the coast of Santa Barbara, California. Although most studies examining the fate and effects of petroleum have focused upon urbanized or anthropogenic sources of inputs, few have examined the effects of polyaromatic hydrocarbons (PAHs) derived from natural seeps. In order to evaluate the effects of PAHs derived from COP on marine fish populations, hatchery-reared California Halibut (Platichthys californicus) were exposed for 30 days to seven dilutions of sediments collected from COP. Hepatic cytochrome P450 1A (CYP1A), biliary fluorescent aromatic compounds (FACs), gonadal somatic indices, and plasma steroid concentrations. Sixteen USEPA priority PAHs were targeted for analysis in each sediment dilution. In general, biochemical responses were somewhat recalcitrant to dose-response relationships and were less sensitive than the literature values established for the same indicators following exposure to urbanized PAHs. Trends toward reductions in plasma 17beta-estradiol concentrations were observed, but reductions in gonadal somatic indices were not observed. FAC values for naphthalene, benzo(a)pyrene, phenanthrene-related compounds reached maximums at 33-100% COP sediment. The resulting insensitivity may be unique for exposure to "natural" petroleum due to a higher concentration of lower molecular weight PAHs or uncharacterized inhibitors.     

A hazard assessment of chemically dispersed oil spills and seabirds

The effects of dispersants on both the exposure to and toxicity of oil to seabirds are considered in order to assess the hazard. Ideally the dispersant mixes with oil and disperses it into the water column. This process is rapid but generally incomplete. The toxicology of one dispersant (Corexit 9527), for which data are available, shows that the toxicity of oil-Corexit mixtures is similar to that of oil alone. The effect of two feeding regimes, pursuit diving and surface diving, is considered. Calculations indicate that the amount of oil that is likely to be taken up by the bird while moving through the water column is small. It is concluded that there is little evidence of synergistic effects between oil and dispersant. The major oiling of birds occurs at the surface and thus dispersants must be highly effective to reduce the exposure of birds to oil.     

Long-term sublethal and short-term high dose effects of physically and chemically dispersed oil on accumulation and clearance from various tissues of juvenile coho salmon, Oncorhynchus kisutch

The toxicity of crude oil and the dispersant BP1100X was tested in sea water and in each case was much less than the toxicity to fish in fresh water. Uptake of oil from water, with or without dispersant, was similar after a short exposure to 200 ppm. The oil was cleared from the fish in three weeks. A long-term exposure to oil or oil plus dispersant at a concentration of 5 ppm showed a slow accumulation but significantly above exposure levels. Thus, salmon exposed to oil in sea water can take up the hydrocarbons but appear to cleanse themselves rapidly.     

Exploring the sublethal genotoxic effects of class II organophosphorus insecticide quinalphos on freshwater fish Cyprinus carpio

The genotoxic effects of quinalphos (QP) were evaluated in the erythrocytes of Cyprinus carpio using the comet, micronucleus, and nuclear abnormality assays. Th...     

Field experiments on the effects of crude oil and dispersant on the common animals and plants of rocky sea shores

In experiments on the Somerset coast, Forties crude oil and BP 1100WD dispersant were sprayed on to small areas of the rocky shore over a period of several days to stimulate conditions following an oil spill. Detailed observations were made at monthly intervals of marked 0.1 m² quadrats within (and without) the treated areas. Some areas received oil only, others dispersant only, and the third set received oil followed by dispersant.The experiments were in two parts, the one to simulate a July incident and the other a January incident.Limpets and the small winkles living in and between empty barnacle shells were the most obviously affected organisms. The sites that received both oil and dispersant were most seriously upset, but the oil areas came next. The effect of BP 1100WD on its own as applied in this experiment was relatively slight.     

Application of a sensitive chemiluminescent technique for comparison of cytochrome P4501A induction in hepatic and intestinal tissues of fish exposed to bleached kraft mill effluent

In conjunction with an environmental assessment of biologically-treated bleached kraft mill effluent (BKME) in a Western Canadian river, data indicated that lipophilic compounds were transferred to the mountain whitefish Prosopium williamsoni through ingestion of filter-feeding benthic caddisflies. P4501A induction was correlated with lipophilic body burdens, not with indices of recent BKME exposure. P4501A contents in hepatic and intestinal tissues of BKME-exposed whitefish were compared during a follow-up collection. Ethoxyresorufin O-deethylase (EROD) activity was not detectable in intestines; P-450 spectral analysis indicated denaturation had occurred. Use of enhanced chemiluminescence (ECL) immunoblotting achieved at least 10-fold greater sensitivity over colorimetric methods and indicated that some intestines did contain P4501A protein. No correlation of intestinal P4501A with hepatic EROD activity or P4501A content was found. Application of the ECL technique significantly improves the analytical detection limits of P4501A immunoblotting. Analysis of historical samples from this site will further probe water-borne versus dietary routes of uptake of BKME-related P4501A inducers in this species.     

Effects of oil and a dispersant on intertidal organisms in field experiments with a Mesocosm,the Bremerhaven Caisson

Three medium-scale field experiments on the effects of oil, a dispersant and an oil/dispersant mixture were carried out in an intertidal mud flat ecosystem of the Wadden Sea (German Bight). For six successive tides each contaminant was added to the water enclosed in a mesocosm during submersion of the flat. The fate of the oil in the sediment and effects on phytobenthos, bacteria and macrozoobenthos were studied. Penetration of the oil into the sediment was mainly observed at the surface layer. were present when oil was chemically dispersed. Sublethal effects were found in some macrofauna species (reduced feeding activity) and in phytobenthic organisms (increased activity); oil degrading bacteria increased. No major effects were observed when the dispersant alone was added.     

A comparison between the international and US regimes regulating oil pollution liability and compensation

Despite its search for a universal oil spill liability and compensation regime, the maritime community continues to face the dichotomy between the US approach and that adopted by the rest of the world. Both regimes have a two-tier structure that is composed of a liability scheme and a fund scheme. However, the significant differences between the two regimes can be found in the liability limit of a responsible party and the scope of recoverable damages. This explains the reasons why the US took a unilateral approach instead of participating in the international one. In the short term, it seems that the current dual system will continue. In the long term, however, it would be desirable to establish a unified international regime which would enable all actors to direct their energies toward handling oil spills rather than grappling with unilateral legislation in individual jurisdictions of the world. Even before an establishment of a unified international regime, harmonization between the two regimes would not only be helpful for the ultimate unification, but also desirable for transactions of the industries concerned under the current dual system.