Automatic sorting of zooplankton by isopycnic sedimentation in gradients of silica: Performance of a “Rho Spectrometer”

The embryonic and larval stages of the quahog clam Mercenaria sp. were exposed to the water-soluble fractions (WSFs) of 6 oils and the effects on survival and growth rate of the various stages were noted. Kuwait crude oil was the least toxic on initial exposure to both stages, having LC₅₀ values in excess of 10 ppm after continuous exposure to the WSF for up to 6 days. However, at 10 days, Kuwait was slightly more toxic than southern Louisiana crude oil, with both oils having LC₅₀ values near 2 ppm. Florida Jay crude oil was much more toxic, with an LC₅₀ of less than 1 ppm at 48 h and less than 0.2 ppm at 10 days. Two refined oils, No. 2 fuel oil and Bunker C, had LC₅₀ values of 1 to 2 ppm after 48 h, while used crankcase motor oil, the most toxic oil tested, had LC₅₀ values of 0.10 ppm or less at all exposure times. Larvae surviving exposure to water-soluble fractions of the various oils often grew at slower rates than the controls.     

Uptake and Dupuration of Petroleum Hydrocarbons By the Backwater Clam,Meretrix Casta Chemnitz

Meretrix casta were experimentally exposed to water soluble fractions of refined and crude oil and their rate of accumulation of the petroleum hydrocarbons including total and individual aromatics viz., naphthalene, methylnaphthalene and dimethylnaphthalene, was studied. Subsequent transfer to clean waters in the laboratory and field resulted in depuration of the accumulated hydrocarbons from tissues. in general, the rate of discharge was found to be dependent on the concentration that the animals had been earlier exposed to and also the alkylation of aromatic hydrocarbons. Occasional increases were observed in the hydrocarbon values of clams which were placed in the field, compared to their laboratory counterparts, suggesting an intermittent source of petroleum hydrocarbon input into the environment. the influence on the rate of uptake, release and retention of hydrocarbons in the clams is discussed.     

A field study of the toxicity of two oils and a dispersant to the mangrove Avicennia marina

The relative toxicities of Arabian Light crude oil, Tirrawarra crude oil, Dispersant BP-AB, and mixtures of oils and dispersant were assessed on 30 mangroves, Avicennia marina (Forsk.) Vierh. var. resinifera (Forst.) Bakh., in a coastal fringe on the eastern shore of Gulf St. Vincent, South Australia. Five treatments were applied: 100% Arabian Light crude oil, 100% Tirrawarra crude oil, Arabian Light crude oil plus dispersant (1:1), Tirrawarra crude oil plus dispersant (1:1) and 100% dispersant. Five mangroves were used for each of the treatments and five as controls. Defoliation, leaf damage, pneumatophore damage, flowering and fruiting were monitored for three years (September 1982–September 1985). Initially, the toxicity of both oils was increased by the addition of dispersant; Tirrawarra crude oil plus dispersant caused significant defoliation. 100% Tirrawarra crude oil was more toxic than 100% Arabian Light crude oil; the former caused significant leaf damage from Week 4 to Week 12 after treatment. After Week 49 production of new leaves was significantly greater in the Arabian Light crude oil plus dispersant treatment than with the Arabian Light crude oil. No such difference was found between the Tirrawarra treatments. Twelve to 26 weeks after treatment, partial pneumatophore damage was observed in all treatments. No atypical flower or fruit production was observed.     

Individual and combined toxicity of some petroleum aromatics to the marine amphipod Elasmopus pectenicrus

Toxicity of 4 components of petroleum oils to the marine amphipod Elasmopus pectenicrus (Bate) has been assessed. Two ephemeral aromatic hydrocarbons, naphthalene (A) and 1, 2, 4-trimethylbenzene (B) were more toxic than two persistent aromatics, o-cresol (C) and o-toluidine (D). The acute toxicity concentrations obtained for individual aromatic compounds were always greater than the actual concentrations found in the water-soluble fractions (WSF) of fuel oils. Results from mixtures of 2 or more components indicated that the LC₅₀ levels were primarily determined by the more toxic substances, A and B. Naphthalene and 1, 2, 4-trimethylbenzene became more toxic to the E. pectenicrus when present in a mixture of more than 2 components, and the toxicity increased with increasing numbers of components present. Synergistic effects, therefore, possibly occur in the whole WSF. No antagonistic effects were observed among the 4 petroleum aromatics.University of Texas, Marine Science Institute Contribution No. 290     

Application of an odd/even predominance of n-alkanes in oil–source rock correlation: taking the lower Paleozoic strata of the Tarim Basin as an example

The composition and distribution of n-alkanes carbon numbers reflect the source of kerogenic organic matter, sedimentary environment, and maturity of the rocks. The comparison results of the n-alkanes GC (gas chromatography) chromatograms in the Tazhong Low Uplift show that the n-alkanes of the source rocks in Upper Ordovician display an odd carbon number predominance. At the same time, Cambrian–Lower Ordovician exhibit an even carbon number predominance. The correlation between oil and source rock illustrates that crude oils in the fields of well TZ10-12 and well TZ24 stem from the Upper Ordovician source rocks. The origins of the crude oils in the fields of well TZ161-162 and well TZ45 are Cambrian–Lower Ordovician. The strata corresponding to the crude oils with odd/even carbon number predominance match the oil–source rock correlation. Thus, the characteristics of odd/even carbon number predominance in n-alkane compounds are effective for oil–source rock correlation in the Tazhong Low Uplift, Tarim Basin.     

Toxicity assessment of crude oils: A methodological view

As a continuity of efforts in the field of laboratory ecotoxicological studies of oil on marine organisms, the present work contains data showing to what extent the observed toxicity of two chemically dispersed crude oils (arabian light and heavy) on well succeeded fish culture species (Lebistes reticulatus) is tightly dependent on the instantaneous measured oil concentration in the bioassay media rather than the initial applied concentrations.     

Investigation of the sources of aliphatic hydrocarbons in the mussel Mytilus edulis from north sea oil production platforms by Capillary glc and CGCMS†

Aliphatic hydrocarbons isolated from mussels collected over a 20 month period from three North Sea Forties field oil production platforms have been examined by capillary gas chromatography and gas chromatography‐mass spectrometry.

The biological hydrocarbons consist predominantly (300–700 μh g^‐1 lipid) of C₃₁ and C₃₃ n‐alkenes with 2, 3 and 4 double bonds probably derived from a dietary intake of Emiliania huxleyi, a microscopic coccolithophorid alga. In some of the mussels C₁₈, C₂₀ and C₂₂ n‐alkanes are present in unusually high abundance compared to their odd carbon number homologues. Possible reasons for this distribution are discussed.

The concentrations of fossil fuel hydrocarbons (mainly unresolved complex mixtures) in the mussels ranged from 330 to 5,298 μg g^‐1 of lipid. No significant increase in values was detected two months after the start of discharge of treated Forties production water from the Forties D platform.

To determine the pollutant hydrocarbon sources, the sterane and terpane distributions of hydrocarbon fractions isolated from the mussels and from a number of fossil fuels, including Forties crude oil, were examined by mass fragmentography. The steranes in the mussels from the Forties C and D platforms contained higher proportions of regular 14α(H), 17α(H) components than Forties oil in which the steranes were mainly 13ß(H), 17α(H) diasteranes. In addition, the terpane distributions of the mussel fractions differed markedly from that of Forties crude oil, particularly in the relative abundance of diterpanes to triterpanes, which was higher in the mussel fractions than in the oil, and in the absence of 17α(H), 18α(H), 21ß(H)‐18, 30‐bisnorhopane, a known component of Forties crude. Furthermore, the ratio of C₂₉ to C₃₀ triterpanes was greater than unity in the mussels but much less than unity in the Forties oil. These data preclude Forties or other similar North Sea crudes as the major source of pollutant aliphatic hydrocarbons in the mussels. The relative concentrations and distributions of steranes and triterpanes suggest that the most likely source of pollutants is a Middle Eastern based oil derived either from rig activities, or from background pollution in the North Sea. The low concentration of ≥ C₂₇ steranes in the more polluted mussels (e.g. Forties B; UCM > 200 ppm dry wt.) suggests that gas oils used on the platforms may be the major source of petrogenic hydrocarbons in these samples.     

Effects of exposure to sublethal concentrations of crude oil on the copepod Centropages hamatus

Female copepods of the species Centropages hamatus show decreased ingestion rates and decreased egg viability when exposed to crude oil/seawater dispersions having crude oil concentrations of 10–80 ppb. However, rates of egg production were not significantly affected by these exposure levels. In addition, we found no evidence for accumulation of petroleum hydrocarbons by copepods exposed to 200 ppb of South Louisiana crude oil. The results imply that biosynthetic pathways involved in oogenesis may be influenced by sublethal concentrations of crude oil or that petroleum hydrocarbons directly affect the viability of eggs. Recruitment into field populations of copepods could be severely reduced as a consequence of exposure to low levels of physically dispersed crude oil.     

石油污染与微生物群落结构的相互影响

从两种土壤中分别分离出石油烃降解菌,并从中筛选出6株石油烃高效降解菌A1、A2、A6、A8和B2及B5,然后将各菌株鉴定至属,分别为A1假单胞菌属、A2鞘氨醇单胞菌属、A6微球菌属、A8节杆菌属、B2不动杆菌属和B5诺卡氏菌属。另外对比分析了单菌株及不同菌株重组对不同石油烃组分的利用情况,结果发现,从不同石油污染的土壤中分离到的菌株对石油烃组分的利用能力不同,从胜利原油污染的土壤中分离到的菌株A1、A2、A6和A8对石油烃组分的利用范围窄,主要利用饱和烃组分;而从经芳香烃驯化过的土壤中分离到的菌株B2及B5对石油烃利用组分的利用范围较宽,能同时利用饱和烃和芳香烃组分。     

Uptake and Dupuration of Petroleum Hydrocarbons By the Backwater Clam, Meretrix Casta Chemnitz

Meretrix casta were experimentally exposed to water soluble fractions of refined and crude oil and their rate of accumulation of the petroleum hydrocarbons including total and individual aromatics viz., naphthalene, methylnaphthalene and dimethylnaphthalene, was studied. Subsequent transfer to clean waters in the laboratory and field resulted in depuration of the accumulated hydrocarbons from tissues. in general, the rate of discharge was found to be dependent on the concentration that the animals had been earlier exposed to and also the alkylation of aromatic hydrocarbons. Occasional increases were observed in the hydrocarbon values of clams which were placed in the field, compared to their laboratory counterparts, suggesting an intermittent source of petroleum hydrocarbon input into the environment. the influence on the rate of uptake, release and retention of hydrocarbons in the clams is discussed.     

Accumulation,fractionation and release of oil by the intertidal clam Macoma balthica

The bivalve mollusc Macoma balthica accumulated hydrocarbons during 180 days of continuous exposure to Prudhoe Bay crude oil in seawater dispersions with nominal concentrations of 0.03, 0.3 and 3.0 mg l^-1. The mollusc's ability to concentrate oil from seawater increased with decreasing oil-in-water concentration. Decreases in oil burden began after 30 to 120 days (depending on the oil concentration) and continued for at least 60 days after exposure to oil ceased. Aliphatic and aromatic hydrocarbons were fractionated in markedly different ways by the bivalve. Branched and cyclic aliphatics in the molecular weight-range dodecane through hexadecane were preferentially retained over straightchain and their higher homologs. Larger and more substituted aromatic compounds were selectively concentrated. There appeared to be no selective concentration of aromatic sulphur compounds.Please address requests for reprints to Dr. D. G. Shaw at the Institute of Marine Science     

Short-term effect of microencapsulated hydrocarbons on shell growth of Mytilus edulis

Two North Sea crude oils, weathered crude oil, n-alkanes, medical liquid paraffin and a fish oil were microencapsulated and added to seawater. This gave a medium containing both water soluble fractions (WSF) and oil particles, and thus simulated the conditions in natural seawater contaminated with oil. The microencapsulated oils were fed to Mytilus edulis L. in different concentrations, and the growth in terms of shell length of the mussels was measured in intervals of 24 to 48 h for 4 to 12d. With the crude oilss A and B, weathered crude oil and n-alkanes at concentrations1 mg l^-1, shell growth rate decreased rapidly compared to controls. With liquid paraffin at levels of 1 to 12 mg l^-1, a small but significant negative effect on shell growth occurred after 5 d of exposure. Exposure to fish oil at 1 and 4 mg l^-1 gave no significant reduction in growth rate. The toxicity of the different hydrocarbons was not related to their content of aromatic fractions. Crude oil B was tested at concentrations ranging from 0.12 to 12 mg l^-1. At 0.12 mg l^-1 shell growth was not significantly different from the control, while at 0.25 and 0.50 mg l^-1 a temporary and significant stimulation of growth was observed. The product concentration (C)xresponse (R) shows a linear regression on exposure time (t). The regression model CxR=75-0.18t is used to estimate EC-values (effect of a given concentration) for given response levels. The model gives a very good fit to observed data.     

Bioenergetics and survival of the marine snail Thais lima during long-term oil exposure

The carnivorous snail Thais lima was fed Mytilus edulis during a 28-d exposure to the water soluble fraction (WSF) of Cook Inlet crude oil. The LC-50 of T. lima declined from >3000 ppb aromatic hydrocarbons on Day 7 to 818±118 ppb on Day 28. The LC-50 of M. edulis declined from >3 000 ppb aromatic hydrocarbons on Day 7 to 1 686±42 ppb on Day 28. Predation rate declined linearly with increasing aromatic hydrocarbon concentration up to 302 ppb; little predation occurred at 538 ppb and none at 1 160 or 1 761 ppb. Snail absorption efficiency averaged 93.5% and did not vary as a function of WSF dose. Total energy expenditure (R+U) increased at 44 ppb aromatics and declined at lethal WSF exposures. At sublethal WSF exposures, percentages of total energy expenditure were: respiration (87%), ammonia excretion (9%) and primary amine loss (4%). These percentages did not vary as a function of WSF dose or time. Oxygen:nitrogen ratios were not affected by WSF concentration or time and indicated that T. lima derived most of its energy from protein catabolism. The uptake of aromatic hydrocarbons into the soft tissues of snails and mussels was directly related to the WSF concentration. Naphthalenes accounted for 67 to 78% of the aromatic hydrocarbons in T. lima and 56 to 71% in M. edulis. The scope for growth was negative above 150 ppb WSF aromatic hydrocarbons and above 1 204 ppb soft-body aromatic hydrocarbons. These snails were physiologically stressed at an aromatic hydrocarbon concentration which was 19% of the 28-d WSF LC-50 (818±118 ppb) and/or 48% of the 28-d LC-50 of soft tissue aromatics (2 502 ppb).     

Hydrogen peroxide (H2O2) requirement for the oxidation of crude oil in contaminated soils by a modified Fenton's reagent

The oxidation of soil organic matter (SOM) and total petroleum hydrocarbon were investigated in two soils at eight different hydrogen peroxide (H₂O₂) concentrations to determine the optimal H₂O₂ dosage for the efficient remediation of soils contaminated by crude oil with minimal SOM removal. In our study, H₂O₂ concentrations up to 1100 mM increased the SOM destruction up to 10%–15% in the two soils while no improvement of the crude oil removal efficiencies was observed. The results indicate that the destruction of SOM significantly limits the oxidation of crude oil because SOM might consume H₂O₂ more effectively than crude oil at H₂O₂ concentrations above 1100 mM. In addition, H₂O₂ concentrations higher than 1100 mM were not expected for both soils because of the extremely rapid H₂O₂ decomposition, and low H₂O₂ utilization, of both soils.     

Chemical composition and effects of water extracts of petroleum on eggs of the sand dollar Melitta quinquiesperforata

Sperm and eggs of sand dollars, Melitta quinquiesperforata (Leske), were subjected to two petroleum oils, and effects determined. The oils chosen were Kuwait crude and No. 2 fuel oil, supplied by the American Petroleum Institute. Water-soluble extracts (WSF) from oil-sea water mixes were prepared and the major aromatic components in the WSF of the fuel oil were identified. WSF of No. 2 fuel oil depressed respiration, mobility of sperm, interfered with fertilization and cleavage, and retarded larval development. The effects were detectable at dilutions of 4% and less (about 0.6 ppm of WSF). Kuwait crude was much less toxic. There was no effect on water permeability of the egg membrane. Results are compared with similar studies on other marine organisms.     

重质原油和轻质原油水溶性组分对紫贻贝(Mytilus edulis)毒理效应的研究

近年来,海洋石油开采与运输泄漏、石油及产品离岸排放等事故逐年增多,对近海海域生态环境产生了巨大破坏。为探究重质原油和轻质原油对紫贻贝(Mytilus edulis)毒理效应,测定了不同浓度重质原油和轻质原油暴露下紫贻贝鳃和外套膜中过氧化氢酶(CAT)和超氧化物歧化酶(SOD)的活性及体内石油烃的含量变化。结果显示,石油污染暴露下,紫贻贝腮和外套膜中CAT和SOD活性变化明显,与暴露浓度和暴露时间有关。CAT活性在轻质原油组随着浓度的增大,呈现下降趋势,且随着暴露时间的延长呈现先下降后上升趋势;在重质原油暴露组,随着浓度的增大,呈现先上升后下降趋势,且随着暴露时间的延长呈现先下降后上升趋势。SOD活性在轻质原油与重质原油暴露组,随着浓度的增大,呈现下降趋势,且随着暴露时间的延长呈现上升趋势并存在一定的剂量-效应关系。重质原油和轻质原油暴露168 h后紫贻贝体内总石油烃含量呈线性递增,生物富集系数(BCF)随着暴露浓度的增加不断减小并最终趋于平稳。结果表明,以紫贻贝腮和外套膜中SOD和CAT活性作为石油烃污染的生物标志物具有一定应用前景,紫贻贝对原油溶液中石油烃的生物富集作用可用来判断污染原油的来源和性质。     

基于物种敏感性分布的保护海水水生生物的石油烃急性毒性基准研究

溢油污染对水生生物的危害以及分散剂使用对原油毒性的影响一直是溢油应急响应及危害评估时关注的焦点。本研究收集筛选了基于标准测试方法的90组急性毒性数据(LC50/EC50),其中37组毒性数据来自15种油品的水容纳组分(water accommodated fraction,WAF),53组来自11种化学分散剂与15种油品的分散液(chemically dispersed water accommodated fraction,CEWAF),应用物种敏感性分布(species sensitivity distribution,SSD)方法推导了基于水生生物保护的石油烃总量(total petroleum hydrocarbon,TPH)的急性毒性基准值,同时还分析了分散剂和不同暴露方式对原油毒性的影响。结果显示,以名义浓度(nominal concentrations)所表示的毒性结果可能高估分散剂对原油毒性的影响,基于CEWAF和WAF的LC50/EC50所推导的有害浓度(HC5s)差异较小,计算出的保护水生生物TPH急性毒性基准值为0.38 mg·L-1(TPH);鱼类对原油污染的响应明显敏感于甲壳类;同时证明了SSD方法在溢油毒性评估及风险阈值推导中具有可行性和合理性。     

Depression of feeding and growth rates of the seastar Evasterias troschelii during long-term exposure to the water-soluble fraction of crude oil

To test the effect of petroleum hydrocarbons on predation by the seastar Evasterias troschelii (Stimpson, 1862) on the mussel Mytilus edulis (L.), we exposed the predator with the prey to six concentrations of the water-soluble fraction (WSF) of Cook Inlet crude oil. Seastars and mussels were collected at Auke Bay, Alaska, in November 1980. During a 28 d exposure in a flow-through system, seastars were more sensitive to the WSF than mussels: the LC₅₀ for the seastars was 0.82 ppm at Day 19 and, although no mussels were exposed to WSF for more than 12 d, none died. Daily feeding rates (whether in terms of number of mussels seastar^-1 d^-1 or dry weight of mussels seastar^-1 d^-1) were significantly reduced at all concentrations above 0.12 ppm. At 0.20, 0.28 and 0.72 ppm WSF, daily feeding rates (in terms of dry weight of mussels) were, respectively, 53, 37, and 5% of the control rate; at the two highest concentrations (0.97 and 1.31 ppm WSF), the seastars did not feed. Seastars at concentrations greater than 0.12 ppm WSF grew slower than individuals from the control group and the 0.12 ppm-treatment group combined. These laboratory results show that E. troschelii is more sensitive to chronic low levels of the WSF of crude oil. The possibility that such oil pollution could reduce predation and permit M. edulis to monopolize the low intertidal zone of southern Alaska remains to be studied.     

Biological effects of oil on early development of the Baltic herring Clupea harengus membras

The effects of petroleum hydrocarbons from two crude oils and one fuel oil (No. 1) were studied on the ontogenic development of the Baltic herring Clupea harengus membras L. Herring eggs exposed to water-soluble fractions of the oils at the time of fertilization showed no decrease in numbers of fertilized eggs compared to eggs exposed 6 or 72 h after fertilization. During embryongenesis, treatment with 3.1 to 8.9 ppm or 3.3 to 11.9 ppm total oil hydrocarbons from light fuel oil and the two crude oils respectively, gave rise to alterations in embryonic activity, decreased heart rate, and premature or delayed hatching. Although many larvae hatched from eggs exposed to contaminated water (3.1 to 11.9 ppm total oil hydrocarbons), the majority of the (70 to 100%) were malformed or dead 1 day after hatching. Exposure of eggs to 5.4–5.8 ppm total oil hydrocarbons resulted in significantly (P<0.001) decreased lengths of the larvae. Increased temperature (from 9° to 14°C) aggravated the effects of the oils. The results are discussed in relation to the potential effects of oil spills and chronic oil pollution on fish eggs and larvae in the Baltic Sea.     

Screening for plants and rhizospheral fungi with bioremediation potency of petroleum-polluted soils in a Tehran oil refinery area

The contamination of soils by toxic and/or hazardous organic pollutants, especially with crude oil, is a widespread problem. This study was conducted in a petroleum-contaminated area in a Tehran oil refinery to find petroleum-resistant plants and their rhizospheral fungal strains with bioremediation potency. The plants growing in the oil-polluted area were collected and determined taxonomically. Root samples of the plant species were collected from a polluted area and fungal strains determined by laboratory methods and taxonomical keys. The growth ability of the isolated fungal strains was studied in media containing 1%–15% crude oil. Results showed that seven plant species were of the highest density in the contaminated area: Alhagi persarum, Hordeum marinum, Peganum harmala, Phragmites australis, Prosopis farcta, Salsola kali, and Senecio glaucus. The root-associated fungi were isolated and showed that the fungal variation in the oil-polluted area is higher than that in a non-polluted area. The growth assay of isolated fungal strains showed that all studied fungal strains were able to form colonies at the applied concentrations but Alternaria sp. and Rhizopus sp. were the most resistant ones. Some plants were resistant to oil pollution, which also had positive effects on the fungal strains.