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1.
Mortality of larval coon-stripe shrimp, Pandalus danae, was related to labile copper and the copper complexing capacity of sea water, as measured by differential pulse Anodic Stripping Voltammetry (ASV). In nominal treatments of control, 5 and 10μg/litre Cu which contained less than 1·0μg/litre ASV labile Cu, zoeal development was usually complete. In treatments of 20 and 50μg/litre Cu which contained more than 7·0μg/litre ASV labile Cu, most larvae died while in the first zoeal stage. ASV labile Cu was related to the copper complexing capacity of sea water. Copper toxicity at less than 1·0 μg/litre ASV labile Cu is indicated by moulting delay and apparent Cu accumulation in zoea of the 5 and 10μg/litre Cu nominal treatments.  相似文献   

2.
The acute toxicity of bromochlorinated estuarine water (ca. 20%) was determined for several estuarine organisms. The most sensitive species were oysters (Crassostrea virginica, larvae and juveniles) and copepods (Acartia tonsa) with 48-h LC50's of 0·10 to 0·21 mg BrCl/litre. Palaemonetes pugio was most tolerant with a 96-h LC50 of 0·70 mg BrCl/litre. The fish species tested (Menidia menidia, Brevoortia tyrannus and Leiostomus xanthurus) all had a 96-h LC50 of 0·21–0·23 mg BrCl/litre.The BrCl toxicity data are compared with Cl2 toxicity data for the same species. When the LC50's are expressed as equivalents per litre, BrCl is found to be two to four times less toxic than Cl2. The ranking of species in terms of sensitivity is the same for both disinfectants.Some data are provided concerning the decay rates of BrCl and Cl2 in estuarine water. BrCl was found to decay more rapidly than Cl2 at higher ammonia levels (0·25 mg NH4-N/litre). The question of chemical speciation is discussed with particular reference to the differential toxicities.  相似文献   

3.
The interaction of selenium with mercury was studied in the shrimp Palaemon elegans. The release of 203HgCl2 (5·0 μg Hg per gramme body weight) from shrimp pretreated with selenium (SeO2 doses of 1·97, 3·95 and 7·90 μg Se per gramme fresh weight) was significantly decreased compared with the control group to which only 5·0 μg Hg/g had been administered.In the presence of HgCl2 (5·0 μg Hg per gramme fresh weight) the release of 75Se also diminished significantly at the higher stable Se pretreated dose (7·90 μg Se/g) while, at a lower selenium concentration, the release was not statistically different. Analyses for stable Hg and Se confirmed the decrease in rate of selenium loss in the presence of mercury which had been demonstrated with radiotracers.A dose of 7·9 μg Se per gramme fresh weight injected 12 h before exposure of the shrimp to the various mercuric chloride solutions did not produce a significant difference in the 24 h LC50 compared with the group not pretreated with selenium. However, during exposure to mercury at 3·8 mg/litre, the median lethal time (LT50) for the shrimp pretreated for 4 days with sublethal selenium (6·9 and 10·5 mg Se/litre) was delayed (19·2 and 33·2 h) compared with the group which was not pretreated. The results are discussed in relation to the role of selenium in the acutely toxic effects of inorganic mercury.  相似文献   

4.
Exposure to a mercury-equilibrated algal suspension containing 0·25, 0·42 and 1 μg Hg litre−1 as mercuric chloride in solution reduced the growth and condition of pairs of adults of the slipper limpet Crepidula fornicata in a 16-week period. Reproduction rates and larval survival to settlement were also reduced over the first three spawnings when the exposed pairs reached sexual maturity. The adult and larval 96-h LC50s were 330 and 60 μg Hg litre−1, respectively, as mercuric chloride in solution, indicating that a ‘safety factor’ of 10−1 needs to be applied to adult data to protect the most sensitive stage in the life cycle. However, the chronic exposure of the maturing adults showed that levels of inorganic mercury below the ‘safe’ concentration derived from the adult 96 h LC50 affected growth and reproductive success.  相似文献   

5.
During 1983 and 1985 several batches of laboratory reared veliger larvae of Mytilus edulis and Pecten maximum here subjected to a rank of concentrations of added copper (CuCl2) over a 15-day period. M. edulis larvae were less sensitive, measured both as mortality (15-day LC50) of 400 μglitre−1) and reduced growth, than P. maximus larvae (15-day LC50 of 85μg litre−1). Both species appeared less sensitive to Cu than other bivallve larvae previously studied. Veliger larvae of M. edulis are from 7 to 10 times more tolerant of Cu than juveniles or adults and this unexpected finding is discussed in relation to the recent literatures on Cu toxicity and accumulation in mussels.  相似文献   

6.
The bi-cyclic aromatic hydrocarbon naphthalene (N) and its alkylated derivatives 2-methylnaphthalene (MN), 2,6-dimethylnaphthalene (DMN) and 2,3,5-trimethylnaphthalene (TMN) were used to investigate possible relationships between increased methylation and toxicity during acute high level and chronic low level exposure experiments using the calanoid copepod Eurytemora affinis Poppe. The 24-h LC50 levels determined indicated an approximate twofold increase in toxicity per methyl group addition: N-3798 μg/litre; MN-1499 μg/litre; DMN-852 μg/litre and TMN-316 μg/litre. Low level chronic exposure of E. affinis to the various naphthalenes in sea water concentrations of about 10 μg/litre for the duration of their adult life (maximum twenty-nine days) resulted in significant reductions in length of life, total numbers of nauplii produced and mean brood size. Exposure to all the naphthalenes at this level (10 μg/litre) resulted in reduced rates of egg production which were, on average, about 50% of those of control animals. Results are discussed in relation to previous work on the fate and effect of petroleum hydrocarbons in marine copepods.  相似文献   

7.
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8.
Uptake of inorganic carbon and ammonium by the plankton community of three North Carolina estuaries was measured using 14C and 15N isotope methods. At 0% light, C appeared to be lost via respiration, and at increasing light levels uptake of inorganic carbon increased linearly, saturated (mean Ik = 358±30 μEin m−2 s−1), and frequently showed inhibition at the highest light intensities. At 0% light NH4+ uptake was significantly greater than zero and was frequently equivalent to uptake in the light (light independent); at increasing light levels NH4+ uptake saturated (mean Ik = 172±44 μEin m−2 s−1) and frequently indicated strong inhibition. Light-saturated uptake rates of inorganic carbon and NH4+ were a function of chlorophyll a (r2 = 0·7−0·9); average assimilation numbers were 625 nmol CO2 (μg chl. a)−1 h−1 and 12·9 nmol NH4+ (μg chl. a)−1 h−1 and were positively correlated with temperature (r2 = 0·3−0·7). The ratio of dark to light-saturated NH4+ uptake tended to be near 1·0 for large algal populations at low NH4+ concentrations, indicating near light independence of uptake; whereas the ratio was lower for the opposite conditions. These data are interpreted as indicative of nitrogen stress, and it is suggested that uptake of NH4+ deep in the euphotic zone and at night are mechanisms for balancing the C:N of cellular pools. A 24-h study using summed short-term incubations confirmed this; the cumulative C:N of CO2 and NH4+ uptake during the daylight period was 10–20, whereas over the 24-h period the ratio was 6 due to dark NH4+ uptake. Annual carbon and nitrogen primary productivity were respectively estimated as 24 and 4·0 mol m−2 year−1 for the South River estuary, 42 and 7·3 mol m−2 year−1 for the Neuse River estuary, and 9·6 and 1·6 mol m−2 year−1 for the Newport River estuary.  相似文献   

9.
Crangon crangon (L.) (Crustacea: Decapoda) were subjected to three metals (Cd, Cu and Zn) at respective concentrations (0·35, 1·6 and 14·4mg/litre) that would induce 50% mortality in 5–6 days. Significantly different (P < 0·05) rates of mortality occurred in the three groups, although their ET50's were almost identical. No moultstage-dependent mortality was observed for Cd, but in Cu and Zn the post-moult stages (A and B) were more susceptible than either the intermoult (Ca and Cb) or premoult (D0–D4) stages.No significant (P> 0·05) sex- or size-dependent mortality was evident at the tested concentrations of these metals.Feeding and ecdysis were inhibited in all metals after day 3 and development from one moult-stage to the next was greatly reduced in Cd.Possible modes of toxicity have been discussed in terms of the physiological condition inferred from the moult-stage at the time of death.  相似文献   

10.
Metals are known to influence lipid peroxidation and oxidative status of marine organisms. Hydrothermal vent mussels Bathymodiolus azoricus live in deep-sea environments with anomalous conditions, including high metal concentrations. Although B. azoricus are aerobic organisms they possess abundant methano and thioautotrophic symbiotic bacteria in the gills. The enzymatic defences (superoxide dismutase (SOD), catalase (CAT), total glutathione peroxidase (Total GPx) and selenium-dependent glutathione peroxidase (Se–GPx)) and lipid peroxidation were determined in the gills of B. azoricus exposed to Cd (0.9 μM), Cu (0.4 μM) and Hg (0.1 μM) with different times of exposure. The experiments were performed in pressurized containers at 9 ± 1 °C and 85 bars.Results show that vent mussels possess antioxidant enzymatic protection in the gills. Cd and Cu had an inhibitory effect in the enzymatic defence system, contrarily to Hg. These enzymatic systems are not completely understood in the B. azoricus, since reactive oxygen species might be produced through other processes than natural redox cycling, due to hydrogen sulphide and oxygen content present. Also the symbiotic bacteria may play an important contribution in the antioxidant protection of the gills.  相似文献   

11.
Concentrations of tributyltin (TBT), dibutyltin (DBT), inorganic and total tin have been measured in water, sediments and deposit feeding clams, Scrobicularia plana, from 25 estuarine locations in England and Wales, in order to compare the bioavailability of different forms of the element. Abnormally high tin values in Scrobicularia from harbours and areas of high boating activity testify to the high bioaccumulation potential of organotins, notably TBT derived from anti-fouling paints, relative to inorganic tin.Infaunal deposit-feeding bivalves consistently contain higher concentrations of TBT than other benthic organisms indicating that sediments may be an important route for uptake. Significant correlations between sediment TBT values and residues in clams such as S. plana (r = 0·81, p < 0·001) support this hypothesis. Direct evidence of the bioaccumulation of sediment-bound TBT is provided from laboratory experiments in which Scrobicularia were exposed to TBT in water and in sediments, either separately or in combination. The results of these experiments clearly demonstrate a predominantly particulate component for TBT uptake in clams.The kinetics of TBT accumulation and elimination were studied in Scrobicularia exposed to sediments containing 0·3 and 1·0 μg/g TBT (as tin). Equilibrium concentrations in tissue are approached after 40 days.Sediments containing 10 μg/g TBT are acutely toxic to S. plana, although such concentrations are only likely to occur close to dockyards and large marinas. Preliminary laboratory and field observations suggest however, that clam populations could be affected at TBT concentrations in sediments of 0·3 μg/g and possibly lower.  相似文献   

12.
Amphipod larvae, Gammarus oceanicus, were exposed for 8 weeks to bis(tributyltin) oxide (TBTO) or tributyltin fluoride (TBTF), or for 5 weeks to leachates from tributyltin-containing antibiofouling paints. No larvae survived 8 weeks' exposure to 3 μg/litre TBTO or TBTF. Differential larval survival occurred during exposure to 0·3 gmg/litre of these same compounds. Paint leachates were shown to cause similar toxicity responses at comparable aqueous tributyltin concentrations. An examination of sublethal responses showed slight decreases in growth for larvae exposed to TBTO and to paint leachates, although responses at tributyltin levels below 1 μg/litre were not marked. Whole-animal oxygen consumption rates were not affected by low tributyltin exposure levels. While these studies demonstrate low level toxicity of tributyltins, effects on oxygen consumption and growth do not indicate a mode of action for these compounds.  相似文献   

13.
The hepatopancreae of the ribbed mussel, Geukensia demissa, and the wedge clam, Rangia cuneata, were examined for their ability to catalyze the reduction/oxidation cycling of the bipyridyl herbicide paraquat. In vitro studies indicated a dose-dependent increase in the rate of superoxide anion (O2−) generation in microsomal fractions supplemented with NADPH; the highest concentration of paraquat employed (4 mm) elicited an 81 % increase in cytochrome c reduction in G. demissa and a 135% increase in R. cuneata. In both .species, cytochrome c reduction was inhibited by the addition of exogenous superoxide dismutase (SOD). For in vivo studies, a single application of paraquat (0·5, 1·0 or 2·0 mm) was added to aerated salt-water aquaria containing G. demissa. Biochemical analyses of antioxidant enzymes, reduced glutathione (GSH) and lipid peroxidation were performed in hepatopancreatic tissue after exposures of 6, 12, 24 and 36 h. Results support the hypotheses that these bivalves can activate redox cycling compounds and demonstrate in vivo responses typical of oxidative stress as observed in other organisms.  相似文献   

14.
The harpacticoid copepod, Nitocra spinipes Boeck, was used as an experimental animal in a series of tests where the toxicity of different fractions (solid and soluble) of TiO2 industrial waste water was investigated. The tests were performed in brackish water (7). Water temperature was used as a variable in the fractionation of the waste water. Temperature was found to influence the acute toxicity of the waste water. LC50 values for N. spinipes were 0·087 (± 4°C), 0·105 (+ 7°C)) and 0·12% (+ 21°C) of undiluted waste water. At room temperature the animal's fecundity was affected at two intervals, one in dilutions between 0·0003% and 0·001% and the other between 0·03% and 0·3%. An acute toxicity test with the dried solid metal fraction resuspended into clean brackish water had an acute LC50 value of 7·6% of undiluted waste water. The results show that different fractions of the waste water have different harmful biological effects under different temperature conditions.  相似文献   

15.
The extent of complexation of calcium(II) and copper(II) with 33 carbohydrates found in seawater has been determined potentiometrically using calcium and copper ion-selective electrodes. The measurements were performed in an essentially neutral aqueous medium at 25°C in 0.70 M KNO3.Neutral sugars form very weak 1:1 complexes with Ca(II) and Cu(II) ions. Sugars with carboxylate groups from much stronger complexes. K′Cu(II) >K′Ca(II)) for a given sugar. The extent of complexation is dependent on the conformation of the sugar ligand.  相似文献   

16.
In order to investigate the mechanism by which o,p′-DDT disrupts endocrine functioning of Nile tilapia in vivo, the estrogenicity of o,p′-DDT was investigated in conjunction with 17β-estradiol (E2) and tamoxifen. Mature, male tilapia were treated intraperitoneally with o,p′-DDT (60 mg/kg, one dose) or E2 (5 mg/kg, four doses) in the presence or absence of tamoxifen (5 mg/kg, six doses) for 12 days and then plasma vitellogenin (Vtg) (measured as alkaline-labile phosphorous), E2, and testosterone (T) were measured. Vtg levels were increased dramatically by E2 (1744±171 μg/ml) and moderately by o,p′-DDT (82±15 μg/ml) compared with controls (23±3.5 μg/ml). Tamoxifen alone had no effect on Vtg production, but inhibited both E2 and o,p′-DDT stimulated vitellogenesis. T levels were reduced with E2 administration (1688±383 pg/ml) and declined further with the combined treatment of E2 and tamoxifen (281±70 pg/ml), compared with controls (6558±1438 pg/ml). Tamoxifen or o,p′-DDT alone did not affect T levels, but their combined treatment did (2069±647 pg/ml). The results of this study suggest that o,p′-DDT is weakly estrogenic in male tilapia, and that this activity may be mediated through the estrogen receptor.  相似文献   

17.
During France JGOFS campaign ANTARES 2 (R.V. Marion Dufresne), samples were taken along a section of the 62°E meridian from 49° to 66°S. The high temperature catalytic oxidation (HTCO) method was used to determine the concentration of dissolved organic carbon (DOC). The analyses were conducted both on-board ship and after the cruise in the laboratory. Collecting and storing acidified samples for post-cruise analysis induced no significant differences. The use of two separate but identical channels on the carbon analyzer increased the number of samples analysed per day and allowed independent monitoring of the instrument blank and the calibration of the detector response. The mixed layer concentrations of organic carbon varied from about 52 μM C in the Antarctic Divergence (64°S) to about 63 μM C in the Polar Frontal Zone (49°S). Vertical profiles showed a slight, but significant, decrease in organic carbon below the mixed layer, to about 42 μM C below 2000 m across the transect. The homogeneity and low concentration of organic carbon in deep water is consistent with values recently reported for the equatorial Atlantic and Pacific Ocean and supports the evidence for a constant deep water DOC concentration. In addition, this provides a verification of the instrument performance, thus validating observed DOC data trends and allowing a comparison with the ‘modern' DOC literature. In general, the organic carbon concentration in the mixed layer was lower than previously published data of the main ocean basins, which might -reflect the low chlorophyll a concentration (<0.5 μg/l) encountered in this region. Along the 62°E meridian section, organic carbon showed a trend with corresponding measurements of phytoplankton biomass and bacterial production, underlining the dependence of bacterial growth on a pool of ‘freshly' produced DOC. Organic carbon was found to exhibit a weak inverse trend versus apparent oxygen utilization (AOU). This suggests that only a small part of the oxygen consumption is due to the mineralisation of DOC.  相似文献   

18.
Chlorination by-products (CBPs) are formed as a result of the cnlorination of power station cooling water for anti-fouling purposes. Their production was studied at 10 coastal power stations in the UK, France and The Netherlands. Three categories of CBPs were determined: trihalomethanes; haloacetonitriles; and halophenols. Bromoform was the CBP most abundantly present in the effluents of all 10 power stations. At a mean chlorine dosage of 0.5–1.5 mg/litre (as Cl2) the mean bromoform concentration was 16.32 ± 2.10 μg/litre. The CBP found in second highest concentrations was dibromoacetonitrile (DBAN) with mean concentrations of 1.48 ± 0.56 μg/litre. Other CBPs detected were dibromochloromethane, bromodichloromethane and 2,4,6-trichlorophenol; concentrations of these three compounds were very low (< 1 μg/litre). At those sites at which bromoform was measured in the dispersing effluent plume it was found to behave as a conservative parameter (Significant direct correlation with plume ΔT).  相似文献   

19.
The acute lethality and sublethal heavy metal contamination potential to marine organisms of a waste brine solution from a potash mining operation were determined. The brine was acutely lethal to marine organisms of the Bay of Fundy, Canada, at concentrations between 47 and 55‰ salinity (96-h LC50 values: threespine stickleback, Gasterosteus aculeatus, 47·7‰; polychaete worm, Nephtys incisa, 52·5‰; blue mussel, Mytilus edulis, lethal to whole animal and reduced ciliary activity of gills above 55‰).The brine diluted to sublethal concentrations (≤40‰) contained manganese (≤ 49·5 ×), copper and zinc (≤ 5·2 ×), lead (≤ 2·6 ×) and cadmium (≤ 0·7 ×) in decreasing order of enrichment relative to control seawater. Copper was accumulated in mussels exposed to these solutions over 44 days to the greatest degree (4 ·4 ×), followed by manganese and lead. Tissue lead concentration reached a steady value within 44 days and cadmium was not accumulated.  相似文献   

20.
Laboratory measurements of all four CO2 parameters [fCO2 ( = fugacity of CO2), pH, TCO2 ( = total dissolved inorganic carbon), and TA ( = total alkalinity)] were made on the same sample of Gulf Stream seawater (S = 35) as a function of temperature (5–35 °C) and the ratio of TA/TCO2 (X) (1.0–1.2). Overall the measurements were consistent to ±8 μ atm in fCO2, ± 0.004 in pH, ± 3 μ mol kg−1 in TCO2, and ± 3 μ mol kg−1 in TA with the thermodynamic constants of Goyet and Poisson (1989), Roy et al. (1993), and Millero (1995). Deviations between the measured pH, TCO2, TA and those calculated from various input combinations increase with increasing X when the same constants are used. This trend in the deviations indicates that the uncertainties in pK2 become important with increasing X (surface waters), but are negligible for samples with the lower X (deep waters). This trend is < 5 μ mol kg−1 when the pK2 values of Lee and Millero (1995) are used.The overall probable error of the calculated fCO2 due to uncertainties in the accuracy of the parameters (pH, TCO2, TA, pK0, pk1, and pK2) is ± 1.2%, which is similar to the differences between the measured values and those calculated using the thermodynamic constants of Millero (1995).The calculated values of pK1, (from fCO2-TCO2-TA) agree to within ± 0.004 compared to the results of Dickson and Millero (1987), Goyet and Poisson (1989), Roy et al. (1993), and Millero (1995) over the same experimental conditions. The calculated values of pK2 (from pH-TCO2-TA) are in good agreement (± 0.004) with the results of Lee and Millero (1995) and also in reasonable agreement (± 0.008) with the results of Goyet and Poisson (1989), Roy et al. (1993), and Millero (1995). The salinity dependence of our derived values of pK1 and pK2, (S = 35) can be estimated using the equations determined by Millero (1995).  相似文献   

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