Effect of varying sediment organic carbon content upon the dermal bioavailability and disposition of benzo(a)pyrene in the catfish, Ictalurus punctatus     

Andrea A. Smith  Russell A. New  Judith E. Wiles  Kevin M. Kleinow 《Marine environmental research》1996,42(1-4)

The dermal absorption of ³H-benzo(a) pyrene (BaP) from sediments of varying organic carbon content was examined in the catfish (Ictalurus punctatus). Test sediments of differing organic carbon concentrations were formulated from natural sediments with the addition of quartz sand to provide organic carbon content of 1.8, 3.7 and 6.1%. Sediments (1.0 g dry wt), spiked with BaP to provide 20.4 μCi at a BaP dose of 75 ng/g, were applied for 6 h to the skin surface (12 cm²) of anesthetized fish. Dermal exposure to BaP in formulated sediments at 6.1, 3.7 and 1.8% resulted in 6-h mass balance bioavailability values of 19.4, 21.9 and 23.2%, respectively. In all treatments, skin in direct contact with sediments had the highest concentration followed by the corresponding muscle layer. Muscle and skin not in direct contact with the labeled sediment had values which averaged 7–580 times lower than the corresponding exposed tissues. Other tissue values ranged from 0.44 pg/g in the heart to 64.21 pg/g in blood. These findings demonstrate appreciable uptake of BaP from surface applied sediments. Within the range examined, varying organic carbon content had a small, but inverse effect upon the dermal bioavailability of BaP.  相似文献   

The effects of petroleum hydrocarbons on lipid metabolism and energetics of larval development and metamorphosis in the american lobster (homarus americanus Milne Edwards)     

Judith M. Capuzzo  Bruce A. Lancaster  Glenn C. Sasaki 《Marine environmental research》1984,14(1-4)

In studies with larval stages of the American lobster (Homarus americanus) exposed to a sublethal concentration of South Louisiana crude oil, the normal patterns of lipid storage, utilization and synthesis during larval development and metamorphosis were altered with oil exposure. Increased rates of protein catabolism, delayed molting and reduced growth were also evident among oil-exposed lobster larvae and suggest either deficiency or immobilization of lipid reserves. From analyses of lipid class composition of control and oil-exposed lobster larvae, it is evident that oil-exposed larvae have consistently lower levels of triacylglycerols (the major energy store) and higher levels of sterols than control larvae. Decreased ratios of non-essential fatty acids (both saturated and unsaturated) and increased ratios of essential fatty acids were detected in the neutral lipid pools of oil-exposed larvae that suggest both decreased storage of fatty acids in energy reserves and decreased mobilization of essential fatty acids into phospholipid pools. The fatty acid distribution in the phospholipid pools of oil-exposed larvae, however, varied little from control values and reflects a tendency to preserve the integrity of these structural lipids. Increases in sterol levels may be related to decreased mobilization of cholesterol or other sterols and/or transformation of cholesterol into metabolic pathways including the biosynthesis of ecdysterone.Oil-exposed animals contained trace quantities of benzene, thiophene, toluene, alkylcyclohexane and alkylbenzenes, detected with GC-MS analyses. No naphthalene, dimethylnaphthalene, higher molecular weight aromatics or their phenolic derivatives were detected; their absence may be related to either the detection limits of the methodology used or extremely rapid metabolism and turnover of these components. Alterations in lipid metabolism may account for the developmental and energetic abnormalities observed in marine crustaceans. It cannot be ruled out, however, that decreased lipid utilization, synthesis and mobilization may be a defense mechanism against incorporating lipophilic components of petroleum hydrocarbons in metabolic pathways, and that disruption in energetics and development is a consequence of the reduction in energy available for growth and molting.  相似文献   

Acclimation to cadmium by Fundulus heteroclitus as demonstrated by fin regeneration and cadmium accumulation     

Judith S. Weis  Peddrick Weis   《Marine environmental research》1985,17(2-4)

There is a body of literature indicating that pre-exposure to low levels of metals may increase tolerance during subsequent exposure.¹ We have previously demonstrated that exposure to cadmium at 100 to 500 μg/liter will retard the rate of fin regeneration in the killifish Fundulus heteroclitus.² These experiments were designed to investigate the effects of pre-exposure to cadmium, using fin regeneration as the parameter of effect. The results indicate that pretreatment allows this species to regenerate faster during cadmium treatment as compared to non-pretreated fish, and that the relationship between the pretreatment and treatment concentrations is relevant to pretreatment effects.  相似文献   

The oceans institute of Canada     

Judith Swan 《Ocean & Coastal Management》1993,21(1-3)

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Microtopography in tidal marshes: Ecosystem engineering by vegetation?     

Judith M. Stribling  Jeffrey C. Cornwell  Olivia A. Glahn 《Estuaries and Coasts》2007,30(6):1007-1015

Hummock-hollow microtopography is characteristic of many freshwater wetland systems. It is comprised of elevated, vegetated hummocks and lower elevation hollows; the latter are usually unvegetated, with reducing conditions in sediments unfavorable for plant growth. This microtopography is also often found in interior regions of brackish marshes, where flood duration is high and salinity fluctuations are prominent. Previous investigation showed this spatial patterning to be relatively stable over time and suggested that these microenvironments are produced by the plants themselves. This study investigates the possible mechanisms and controlling factors of this microtopography and considers the effect of different salinity regimes. We examined microtopographic variability of vegetation and sediment biogeochemistry in two interior tidal marshes, a freshwater-oligohaline marsh and a mesohaline marsh, both of which exhibited fine-scale spatial variability. Within a 2-yr period, the freshwater-oligohaline site demonstrated a labile response of both vegetation and sediment chemistry to interannual variability in salinity and sulfide concentrations, whereas the microscale spatial variability of the mesohaline system persisted. Geochronological assessment of the mesohaline marsh, where microtopographic variability was relatively stable, supported the hypothesis that the formation of the hummock-hollow topography is driven by the plants, rather than developing as a result of underlying physical variability. We propose that brackish marsh vegetation alters the sedimentary environment in such a way as to maximize growth under high-stress, variable conditions. The adaptive advantage of this strategy was illustrated in the accretion rates measured at the higher salinity marsh, which were indistinguishable between the interior hummock sediments and those of an adjacent homogeneous bank marsh.  相似文献   

Intercomparison of Boron Isotope and Concentration Measurements. Part II: Evaluation of Results   总被引：3，自引：1，他引：3  

Roberto Gonfiantini  Sonia Tonarini  Manfred Grning  Alessandra Adorni‐Braccesi  Assad S. Al‐Ammar  Marcus Astner  Sebastien Bchler  Ramon M. Barnes  Randy L. Bassett  Alain Cocherie  Annette Deyhle  Andrea Dini  Giorgio Ferrara  Jrme Gaillardet  Judith Grimm  Catherine Guerrot  Urs Krhenbühl  Graham Layne  Damien Lemarchand  Anette Meixner  D. Jack Northington  Maddalena Pennisi  Eva Reitznerov  Ilia Rodushkin  Naoji Sugiura  Regina Surberg  Sabine Tonn  Michael Wiedenbeck  Samuel Wunderli  Yingkai Xiao  Thomas Zack 《Geostandards and Geoanalytical Research》2003,27(1):41-57

The Istituto di Geoscienze e Georisorse (IGG), on behalf and with the support of the International Atomic Energy Agency (IAEA), prepared eight geological materials (three natural waters and five rocks and minerals), intended for a blind interlaboratory comparison of measurements of boron isotopic composition and concentration. The materials were distributed to twenty seven laboratories - virtually all those performing geochemical boron isotope analyses in the world -which agreed to participate in the intercomparison exercise. Only fifteen laboratories, however, ultimately submitted the isotopic and/or concentration results they obtained on the intercomparison materials. The results demonstrate that interlaboratory reproducibility is not well reflected by the precision values reported by the individual laboratories and this observation holds true for both boron concentration and isotopic composition. The reasons for the discrepancies include fractionations due to the chemical matrix of materials, relative shift of the zero position on the δ¹¹B scale and a lack of well characterized materials for calibrating absolute boron content measurements. The intercomparison materials are now available at the IAEA (solid materials) and IGG (waters) for future distribution.  相似文献   

The effect of temperature on the toxicity of chlorinated cooling waters to marine animals — A preliminary review     

Judith M. Capuzzo 《Marine pollution bulletin》1979,10(2):45-47

The effect of temperature on the toxicity of free chlorine and chloramine to several species of marine animals is reviewed. For all species tested, except the copepod Acartia tonsa, temperature has a synergistic effect on the toxicity of both halogen forms. It is suggested that the effect of temperature in enhancing the toxic effects of chlorinated cooling waters to marine animals is due to an interaction of uptake rates and regulation of physiological rates and the greatest enhancement in sensitivity could be expected at the upper limit of a species' thermal tolerance.  相似文献   

On the stable carbon and oxygen isotopic composition of some shallow water,ahermatypic, scleractinian coral skeletons     

Lynton S. Land  Judith C. Lang  David J. Barnes 《Geochimica et cosmochimica acta》1977,41(1):169-172

The δC¹³ and δO¹⁸ values of skeletons of shallow water, ahermatypic scleractinian corals from Jamaica show an excellent correlation over a wide range of isotopic composition. Within individual specimens there are large differences in the isotopic composition of separate skeletal elements. Some of these ahermatypes are enriched in O¹⁸ relative to equilibrium precipitates of calcium carbonate from Jamaican sea water. Therefore our data do not support a two-reservoir mixing model for calcification if one of these reservoirs consists of dissolved marine (inorganic) bicarbonate. As some of these ahermatypic species are enriched in both C¹³ and O¹⁸ relative to hermatypic corals from the same reefs, calcification models based on withdrawal of metabolic CO₂ by photosynthesizing zooxanthellae must also be modified.  相似文献   

Sponge gemmules from lake sediments in the Puget Lowland,Washington     

Judith Turner 《Quaternary Research》1985,24(2):240-243

Gemmules of five species of freshwater sponge found in deposits at Cedar Mountain bog in the southeastern Puget Lowland were used to infer that during the late-glacial period the water was calcareous, was not deficient in SiO₂, was aerobic, and had a pH in the range 6.6–8.5. This is consistent with plant fossil data. In view of their paleoenvironmental potential it is worth looking for gemmules when extracting other fossils from lake sediments.  相似文献   

Hydrogeochemical exploration and sources of anomalous waters     

R.B. Hoag Jr.  G.R. Webber 《Journal of Geochemical Exploration》1976,5(1-2)

Fifty-four surface and twenty drill-hole waters were sampled in the vicinity of the old Eustis mine in the Eastern Townships of Quebec. Some of these waters were tested periodically over a three-month period. The purpose of the investigation was to develop a method for locating sources of anomalous waters using chemical analyses together with geomorphic and geologic evidence. Techniques have been developed which use chemical and hydrologic theory to estimate travel distance and location of the approximate source area of a water. The travel distance can be approximated as a function of hydraulic head, sodium concentration in the water, and an approximate constant which must be derived for the area.Water samples having anomalous concentrations of copper or zinc can be ascribed, in the specific region of this investigation, partly to contamination from mine workings (35%), partly to known mineralization (25%), and partly to unknown causes (40%).  相似文献