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1.
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   

2.
Polycyclic aromatic hydrocarbon (PAH) bioaccumulation by the polychaete worm Streblospio benedicti (Webster) was measured under exposure to PAH-contaminated sediments in the field and for 28 d in the laboratory. Streblospio benedicti collected from field sediments contaminated at 2.94, 1.07, and l.52 μg g−1 fluoranthene (FLU), benz[a]anthracene (BAA), and benzo[a]pyrene (BAP), bioaccumulated those PAHs at 1.53, 0.215, and 0.332 μg g−1, while worms isolated from less contaminated field sediments (0.399, 0.228, 0.288 μg g−1 FLU, BAA, and BAP) had FLU, BAA, and BAP body burdens of 0.543, 0.236, and 0.083 μg g−1. Worms incubated for 28 d in PAH-spiked sediments (1.52, 0.991, 0.504 μg g−1 FLU, BAA, and BAP) bioaccumulated those PAHs at 0.382, 0.966, and 0.602 μg g−1, respectively. Data normalization to organism lipid and sediment organic carbon (biota-sediment accumulation factors [BSAFs] strongly suggest that Streblospio PAH bioaccumulation was directly related to percent sediment organic carbon, but BSAFs were substantially lower than predicted by equilibrium partitioning theory. BSAFs decreased with increasing PAH log Kow, in worms collected from field sediments, but in spiked sediments BSAFs increased with increasing PAH hydrophobicity. This disparity may have been caused by insufficient spiked-sediment equilibration time (1.5h) in the case of the laboratory test sediments.  相似文献   

3.
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   

4.
Results of trace metal analyses performed on two species of Euphausiacea, Meganyctiphanes norvegica and Stylocheiron longicorne, and one species of Decapoda, Sergestes arcticus, collected off the east coast of Corsica, are reported. Analyses were carried out by atomic absorption spectrophotometry and by differential pulse anodic stripping voltammetry.S. arcticus contained lower concentrations of phosphorus (which was also analysed as a biological indicator), cadmium (0.33 μg g−1), copper (17.7 μg g−1), lead (2.13 μg g−1) and zinc (51 μg g−1) than the two Euphausiacea (0.50 μg Cd g−1, 25.4 μg Cu g−1, 4.03 μg Pb g−1 and 59 μg Zn g−1). Moreover, manganese concentrations were low in all the samples.When the results presented here are compared with previous results on phytoplankton and mesozooplankton, there appears to be no trend of trace metal enrichment from phytoplankton to the Decapoda.  相似文献   

5.
Macroalgae biomass and concentrations of nitrogen, phosphorus and chlorophyll a were determined weekly or biweekly in water and sediments, during the spring-summer of 1985 in a hypertrophic area of the lagoon of Venice. Remarkable biomass production (up to 286 g m−2 day−1, wet weight), was interrupted during three periods of anoxia, when macroalgal decomposition (rate: up to 1000 g m−2 day−1) released extraordinary amounts of nutrients. Depending on the macroalgae distribution in the water column, the nutrients released in water varied from 3·3 to 19·1 μg-at litre−1 for total inorganic nitrogen and from 1·8 to 2·7 μg-at litre−1 for reactive phosphorus. Most nutrients, however, accumulated in the surficial sediment (up to 0·640 and to 3·06 mg g−1 for P and N respectively) redoubling the amounts already stored under aerobic conditions, Phytoplankton, systematically below 5 mg m−3 as Chl. a, sharply increased up to 100 mg m−3 only after the release of nutrients in water by anaerobic macroalgal decomposition. During the algal growth periods, the N:P atomic ratio in water decreased to 0·7, suggesting that nitrogen is a growth-limiting factor. This ratio for surficial sediment was between 6·6 and 13·1, similar to that of macroalgae (8·6–12·0).  相似文献   

6.
Determinations of Cu, Co, Ni and Cd were carried out on 39 samples of surface seawaters from the Ligurian Sea, nearshore and offshore, between the Isola Capraia and Imperia. The concentrations of trace elements have been established employing the analytical method suggested by Le Meur and Courtot-Coupez (1973), by means of concentration of the sample by chelating resin, solvent extraction of the eluate and then by quantitative determination by AAS. The results obtained with this technique probably refer to ionic forms of the elements only. The Co concentration was lower than 0.15 μg 1−1 in 32 samples, with an average of 0.49 μg 1−1 for the others. For Cd, the greater number of samples had a content lower than 0.05 μg 1−1. For the others the mean concentration was 0.13 μg 1−1. The Ni had a mean concentration of 0.93 μg 1−1 and the average Cu content was 1.43 μg 1−1. Our data are in agreement with the values published by authors who have employed the same analytical technique. We observed that the offshore samples present a concentration lower than that in the nearshore samples.  相似文献   

7.
Cultures of six marine phytoplankton were grown at ammonium concentrations ranging up to 200 μg-atom NH4---N litre−1. Only the growth of dinoflagellates, Gymnodinium splendens and Gonyaulax polyedra was inhibited at the two highest concentrations used. In 3-h photosynthetic 14CO2 uptake experiments, only Gymnodinium was inhibited at concentrations of NH4---N greater than 100 μg-atom litre−1. We conclude that the increased ammonium concentrations found near Southern California sewage outfalls would not be inhibiting to phytoplankton in the vicinity of such outfalls.  相似文献   

8.
Field and laboratory work was carried out during the summers of 1990 and 1991 on bivalves Scrobicularia plana from sites moderately-affected and relatively-unaffected by tributyltin (TBT) contamination (i.e. a mean concentration in clam tissues of 0.4 and 0.02 μg Sn g−1 dry wt, respectively). Standard cultures after artificial fertilizations with broodstock of either site did not result in dissimilar survival of embryos nor in larvae of different quality at the time of hatching. Static 48 h toxicity tests on S. plana embryos showed that an EC50 of less than the nominal 250 ng Sn litre−1 (a range of 178–198 ng Sn litre−1, as analysed) can be set for TBT independently of the origin of broodstock. The results are discussed in relation to the reported disappearance of S. plana throughout northern Europe and the simultaneous presence of toxic levels of butyltin. It is concluded that TBT has probably reduced the recruitment into some UK clam populations by preventing the successful development of a significant proportion of their embryos.  相似文献   

9.
No. 2 fuel oil-sea water dispersions were added to three large scale (13 m3) microcosms twice weekly for a period in 1977 and a 4 month period in 1978. Water column concentration of total hydrocarbons averaged 190 μg litre−1 in 1977 and 93 μg litre−1 in 1978. Several responses of t the phytoplankton community in the oiled microcosms, relative to control microcosms, were similar during both periods of oil addition: total phytoplankton abundance and chlorophyll concentration were elevated, species diversity was higher and diatoms represented a greater proportion of the total p phytoplankton abundance than flagellates during 4 months of oil addition in 1977 and the entire period of oil addition in 1978. Phytoplankton species composition in the oiled microcosms was similar to the source water, Narragansett Bay, but the microcosm assemblages were numerically dominated by populations of the diatom Chaetoceros spp. and nanoflagellates in 1977 and several Chaetoceros spp. in 1978. Reduced predation pressure and altered herbivore feeding behaviour combined with the low level, non-lethal (to the majority of phytoplankton populations), concentrations of No. 2 fuel oil in the water column are postulated as mechanisms that can account for the elevated phytoplankton abundance in the oiled microcosms relative to the controls.  相似文献   

10.
Ammonium concentrations were found to be elevated near Southern California sewage outfalls; concentrations exceeding 3 μg-atom litre−1 were measured 5 km from the discharge area. In stratified water, high values were found below 15 m, but in well-mixed water, high levels were detected at the surface. Subsurface high concentrations were associated with turbid layers, coliform bacteria and reduced oxygen levels. The distribution of ammonium correlated well with measured subsurface currents. The maximum concentration at the Whites Point outfall was 155 μg-atom litre−1 at 27 m, about 2 km from the diffuser. Measurements of ammonium in sewage, compared with that in seawater at Whites Point, suggested that sewage was diluted up to 400-fold. Ammonium may be a useful tracer of the discharge of sewage in seawater.  相似文献   

11.
Rates of net nitrification were calculated for four large (13 m3) estuarine-based microcosms that had been subjected to inorganic nutrient enrichment. Calculated rates were based on two years of weekly nitrate and nitrite measurements and ranged from a maximum of 0·55 μmol NO2+3− produced l−1 day−1 in the control tank (no enrichment) to over 13 μmol NO2+3− produced l−1 day−1 in the most enriched tank (receiving 18·6 μmol NH4 l−1 day−1). Almost all NO2+3− production was pelagic, little was benthic. Net NO3− production or net NO2− production dominated the net nitrification rates during different seasons. Good correlations were found between various oxidation rates and substrate concentrations. The calculated net nitrite production rates were 10 to 1000 times higher than previously reported rates for open ocean systems, demonstrating the potential importance of nitrification to estuarine systems.  相似文献   

12.
Twenty-two different species of Arctic brown, red and green macroalgae, collected in the Kongsfjord at Ny-Ålesund (Spitsbergen), were incubated under polar conditions and investigated for their release of volatile halogenated organic compounds (VHOC). Bromoform, dibromomethane, dibromochloromethane, bromodichloromethane, 1,2-dibromoethane, diiodomethane and chloroiodomethane have been identified and their net releases during incubations were determined. Generally, brown and green macroalgae showed higher VHOC release, while red macroalage had only low release. Bromoform was released in relatively large quantities from all species studied, with the highest release observed from the brown algae Dictyosyphon foeniculaceus (0.3 μg g−1 wet algal weight day−1) and Laminaria saccharina (0.15 μg g−1 wet algal weight day−1), and from the green algae Monostroma arcticum (0.3 μg g−1 wet algal weight day−1) and Blidingia minima (0.27 μg g−1 wet algal weight day−1). Dibromomethane, diiodomethane, dibromochloromethane and 1,2-dibromoethane showed lower net release during the incubations. The net release of chloroiodomethane and bromodichloromethane was very low for the most algae species investigated. Based on the distribution of these algae in the Arctic environment, Dictyosiphon foeniculaceus and Laminaria saccharina may be important sources for VHOC because of high release and high biomass. Release of VHOC could be detected from all parts of the thallus of the macroalga. This may provide some evidence for a possible role of VHOC production as a chemical protection mechanism in algae.  相似文献   

13.
The influence of salinity on growth and Cu uptake in the green macroalga Ulva reticulata collected from the intertidal area in the Western Indian Ocean was studied under controlled laboratory conditions. Exposure concentrations ranged from 5 to 500 μg Cu l−1 at five salinities (ranging 20–40). The accumulation of Cu increased with decreasing salinity, so that the uptake at 500 μg Cu l−1 was approximately 2.7, 2.4 and 2.0 times higher at salinities of 20, 25, and 30 respectively, than uptake at salinity of 35, and with uptake being lowest at salinity of 40. Ulva maintained a positive growth rate over the whole salinity range (20–40), with highest rates at salinity of 35. When exposing to Cu at low salinities (20 and 25), the growth rate of Ulva was strongly inhibited suggesting an increase in toxicity of Cu with decreasing salinity. EC50 and NOEC increased with increase in salinity, implying a reduced Cu toxicity at high salinities. It was concluded that salinity needs to be considered when using macroalgae, such as U. reticulata, as a bioindicator of heavy metals in areas with heavy rainfall, underground fresh water intrusion or in estuaries, as they might accumulate more metals and be more negatively affected.  相似文献   

14.
The effect of dissolved petroleum hydrocarbons in the environment on phytoplankton biomass measured as chlorophyll a was studied near the oil tanker route in the southern Bay of Bengal. In the transect from 5° N, 77° E to 5° N, 87° E the concentrations of dissolved petroleum hydrocarbons were negatively correlated with phytoplankton biomass, whereas in the 0° N, 87° E to 1° N, 79° E transect they were positively correlated with phytoplankton biomass. The mean petroleum hydrocarbon concentrations in the two transects were 12·12 ± 4·67 μg litre−1 and 11·23 ± 4·5 μg litre−1, respectively.It is surmised that the effect of dissolved petroleum hydrocarbons on phytoplankton biomass varies depending on the nature rather than the quantity of petroleum hydrocarbons present. Culture studies with unialgal Nitzschia sp. in seawater collected from selected stations in the study area as well as in artificial seawater spiked with the water-soluble petroleum hydrocarbon fraction of light Arabian Crude support this.  相似文献   

15.
Specific effects of tributyltin (TBT) on Crassostrea gigas—valve thickening, and Nucella lapillus—imposex, were measured on local populations, relatively clean unaffected species from England were transferred to the Netherlands and exposed during six weeks to ambient TBT concentrations. Near marinas 50% of the exposed species were sterile after six weeks. In general, no dissolved butyltins were detected in the Rhine and Scheldt estuaries. In 1988 TBT concentrations in marinas ranged from 120 to 4000 ng litre−1. In sediments (fraction <60 μm) and suspended particulate matter TBT concentrations reached up to 1200 ng g−1. TBT concentrations in mussel tissue ranged from <1 to 2300 ng g−1 based on a dry weight. In 1989 concentrations of dissolved TBT ranged from <0·1 to 7200 ng litre−1. In 1989 a seasonal study in the marina of Colijnsplaat showed that dissolved butyltins increased from April to the end of May due to the launching of freshly painted boats, and decreased afterwards.  相似文献   

16.
In order to assess the adaptation to metals previously observed in the bioindicator organism, Macoma balthica, subjected to chronic contamination by silver and mercury in the French Loire estuary, the bioaccumulation potential of individual organisms originating from the contaminated Loire estuary and a relatively uncontaminated control estuary (Somme) was evaluated using both radiotracers and stable isotopes of Ag (80 μg Ag litre−1) and Hg (100 μg Hg litre−1). Clams from the contaminated estuary were more sensitive to Ag (LT50 = 9d) than those originating from the Somme estuary (LT50 > 15d), even though the former bioaccumulated Ag to a significantly lower degree. This is attributed to a consequence of the chronic stress induced by Ag while clams were living in their natural environment. Therefore, past history of trace metal contamination should be considered when evaluating the susceptibility of M. balthica to heavy metal exposure. Lower uptake rates obtained for Hg (during the initial uptake phase only) and for Ag in clams from the polluted estuary suggest the presence of an adaptive trait for survival in contaminated areas. However, the lower degree of bioconcentration observed for Ag was not sufficiently low to reduce the sensitivity of the organisms to Ag and allow them to resist the toxic stress. Clams that survived Ag or Hg exposure at LT50 did not protect themselves against metal toxicity by accumulating a significantly lesser amount of these metals than clams which did not survive metal stress. The results suggest that the bioaccumulation potential of each individual was not a factor which can explain the survival ability of M. balthica exposed to chronic Ag and Hg contamination in estuaries. In this case, cellular, biochemical and genetic levels of adaptation are presumed to be of greater importance.  相似文献   

17.
A worldwide literature survey of data on cadmium concentration in the soft tissue of the mussel, Mytilus spp., from 591 stations is presented. These stations are from 13 regions. Geometric means for the regions vary from 0·6 to 3·3 μg g−1 (dry weight) for the Barents Sea and the Northeastern Pacific coast, respectively.The averages of seven of these regions, for which reliable cadmium concentrations in seawater were available, were used to calculate a relationship between cadmium concentrations in seawater and mussel soft tissue. The relationship was highly significant: (Cd) mussel (μg g−1, dry weight) = 0·074 (Cd) water (ng litre−1) + 0·39 (P ≤ 0·0005).This model has been successfully applied in the context of the contamination of the Gironde estuary (France). It can also be used to define a water quality criterion for mussel maturing parks consistent with the quality criterion defined for shellfish for human consumption.  相似文献   

18.
Concentrations of bacteria, chlorophyll a, and several dissolved organic compounds were determined during 11 tidal cycles throughout the year in a high and a low elevation marsh of a brackish tidal estuary. Mean bacterial concentrations were slightly higher in flooding (7·1 × 106 cells ml−1) than in ebbing waters (6·5 × 106 cells ml−1), and there were no differences between marshes. Mean chlorophyll a concentrations were 36·7 μg l−1 in the low marsh and 20·4 μg l−1 in the high marsh. Flux calculations, based on tidal records and measured concentrations, suggested a small net import of bacterial and algal biomass into both marshes. Over the course of individual tidal cycles, concentrations of all parameters were variable and not related to tidal stage. Heterotrophic activity measured by the uptake of 3H-thymidine, was found predominantly in the smallest particle size fractions (< 1·0 μm). Thymidine uptake was correlated with temperature (r = 0·48, P < 0·01), and bacterial productivity was estimated to be 7 to 42 μg Cl−1 day−1.  相似文献   

19.
Laboratory exposures of the urchin Lytechinus pictus to sediment dosed with varying concentrations of hydrogen sulfide (H2S), but without elevated organic material, were conducted. Changes in mortality, behavior, growth and gonad production were measured during 49 days' flow through exposures. Hydrogen sulfide concentrations of 165·8 μ liter−1 in pore water caused significant changes in all parameters measured. Concentrations as low as 32·9 μ liter−1 caused significant decreases in wet weight and male gonad production. A concentration of 91·8 μ liter−1 caused the mortality rate to increase 100-fold over control exposures (0·63 μ liter−1). Sublethal effects on growth and gonad production could have been caused by either direct biochemical inhibition by H2S or secondarily through behavioral modifications. Hydrogen sulfide concentrations above 165·8 μ liter−1 are common near sewage outfalls and could contribute to changes in species composition and sediment toxicity that occur there.  相似文献   

20.
Fatty acids and hydrocarbons of sedimenting particles were investigated in the northeastern Adriatic Sea from November 1988 to December 1989. Particles were collected at approximately monthly intervals, using sediment traps deployed at 30 m depth (2 m above bottom). Seasonal changes in sedimentation of particulate matter were very pronounced. Hydrocarbon fluxes and concentrations were found to vary significantly depending on the season. They averaged 2.69 ± 1.44 mg m−2 day−1 and 232.4 ± 90.93 μg g−1 in winter, respectively. In late spring-early summer the corresponding values amounted to 0.045 ± 0.015 mg m−2 day−1 and 13.72 ± 5.56 μg g−1, and they increased towards autumn, when mean values of 0.517 ± 0.228 mg m−2 day−1 and 98.86 ± 48.72 μg g−1 were obtained. In contrast, fatty acid fluxes and concentrations were low during winter (0.26 ± 0.08 mg m−2 day−1 and 21.95 ± 3.35 μg g−1), increased slightly towards the summer (0.48 ± 0.12 mg m−2 day−1 and 139.9 ± 44.6 μ g−1) and reached maximum rate and concentration in autumn, when average values were 1.98 ± 1.30 mg m2 day−1 and 489.1 ± 186.7 μg g−1, respectively. The differences in composition, concentrations and fluxes of the fatty acids and hydrocarbons were related to the sources of sedimenting material, reflecting the influence of resuspension of bottom sediments during winter and the appearance of mucus aggregates during summer and their subsequent deposition in autumn.  相似文献   

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