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1.
Between January 1978 and September 1979 samples of subsurface (1 m) water and surface sediment were collected from sites in the North Sea, English Channel, Irish Sea and a number of estuarine areas. These have been analysed by fluorescence spectroscopy (UVF) in order to provide information on the levels of hydrocarbons generally present in UK marine waters.Total hydrocarbon concentrations (THCs) of water samples ranged from 1.1–74 μg l.?1 Ekofisk crude oil equivalents, all values greater than 3.5 μg l.?1 occurring inshore. In offshore areas the mean THCs were: 1.3 μg l.?1 in the northern North Sea, 1.5 μg l.?1 in the western Channel, 2.5 μg l.?1 in the eastern Channel and southern North Sea, and 2.6 μg l.?1 in the Irish Sea.THCs of sediment samples ranged from 0.27–340 μ g?1 dry weight Ekofisk crude oil equivalents, the highest concentration being in the Queen's Channel, the main entrance to the River Mersey.  相似文献   

2.
The coastal waters of Hong Kong constitute a transition from estuarine conditions in the west to more oceanic conditions in the east, with a major discharge of untreated sewage located at the mid-point. Chlorophyll a was determined and net phytoplankton was sampled at 45 stations throughout this transition. Over a period of 20 months, chlorophyll a values rarely exceeded 2 μg l.?1 in unpolluted coastal waters. Estuarine waters generally contained 2–6 μg l.?1 and, in waters influenced by sewage discharge, values sometimes exceeded 20 μg l.?1. There was no evidence of a reduction in taxonomic diversity in polluted areas except in summer, when the net phytoplankton was dominated by Chaetoceros spp. In the autumn and early winter, Skeletonema costatum was abundant in the central polluted areas.  相似文献   

3.
For the gas-chromatographic determination of thiocyanate in waters two enrichment processes were used: 1) the evaporation of the water sample on the water bath and 2) the adsorptive enrichment on Wofatit EA 60. As the example of the investigation of water samples from the Baltic Sea has shown, the less selective process 1 gave higher results of measurements than the adsorptive method 2. As compared with the GDR's coastal region of the Baltic (0.4 … 5.2 μg/l), the SCN? concentrations (1986) in the western offshore region (0.1 … 2.1 μg/l) are considerably lower. With increasing depth and growing salt content the SCN? concentration in the Baltic decreases. Anthropogenic influences, such as the input of residual products of sewage works effluents, can be inferred from the relatively increased SCN? concentrations in the coastal region.  相似文献   

4.
Samples of seawater from sites along the southwest coast were collected during 1984 and analysed for total tin and organotin by flameless atomic absorption spectro-photometry. Organotin concentrations were below detection limits (0.10 μg l?1 TBTO) at all marina sites, but higher concentrations were found in harbour waters, the highest value being 0.88 μg l?1 TBTO at Plymouth (Sutton harbour). The fact that organotin levels may occasionally exceed some toxicological threshold concentrations suggests that biological water quality may sometimes be depressed.  相似文献   

5.
Total mercury concentrations were determined in a variety of fish and invertebrates and two dugongs from the coastal waters of Townsville on the N.E. coast of Australia. Fish generally contained the highest levels of mercury with 50% of the sharks examined having muscle concentrations above 0.5 μg g?1 wet weight. A significantly positive correlation was found between muscle levels and body length in sharks. Seventy per cent of the teleosts examined contained less than 0.2 μg g?1 in their muscle tissue and only 7% were above 0.5 μg g?1. Mercury concentrations in teleost liver were significantly positively correlated with muscle levels. Of the invertebrates examined, the cephalopod molluscs contained the highest levels although none exceeded 0.5 μg g?1. Mercury levels in the dugong were extremely low compared with most reported values for other marine mammals. It was concluded that the area contained mercury levels slightly above those considered normal for a non-contaminated marine environment.  相似文献   

6.
The aim of this study is to investigate the concentrations of U, Th, V, Mo, and Zr in natural waters taken from Turkey. Among these water species, Lake Van is the largest soda lake and the fourth largest closed basin on Earth. The water samples were collected from 51 locations between 2008 and 2009. The inductively coupled plasma‐MS was used for determinations. The obtained U and Zr concentrations are in the range of 37–110 µg L?1 and 17–78 µg L?1 in Lake Van and 0.53–0.81 µg L?1 and 0.15–0.19 µg L?1 in Lake Hazar, respectively. The concentration of uranium in other studied waters varies from the lowest 0.09 µg L?1 in Tigris (Dicle) river to the highest 4.0 µg L?1 in Mediterranean Sea water. Mean Mo and V concentrations in the studied water samples were found to be in ranges of 0.1–17 and 2.7–113 µg L?1, respectively. The obtained highest U concentration in Lake Van correlates with the highest Mo and Zr levels compared to the Lake Hazar and river waters. These results imply that there is a young occurrence of uranium minerals around Lake Van. It is concluded that there is about 50.000 ton of uranium in Lake Van water.  相似文献   

7.
Total arsenic concentrations have been measured in macroalgae specimens from two coastal areas of South Australia. Phaeophyta in both areas were found to contain elevated arsenic concentrations (42.2–179 μg g?1 and 26.3–65.3 μg g?1) relative to Rhodophyta (17.6–31.3 μg g?1 and 12.5–16.2 μg g?1) and Chlorophyta (6.3–16.3 μg g?1 and 9.9–10.8 μg g?1).  相似文献   

8.
The iodide contents in 389 ground-water-tapping plants of the county are compared with the geological character of the aquifer, the carbonate and non-carbonate hardness and the nitrate and chloride contents of the waters. 54% of the plants have I-concentrations of 3 … 7 μg/l. In the air-covered ground-water (hardness quotient<2.8) 2 … 50 μg/l I are found, whereas in the confined ground-water (hardness quotient >2.8) 2 … 50 μg/l I are contained. In general, the I-content increases with the carbonate hardness, a connection with till existing. Therefore, ground-waters of the Miocene have relatively low salt- and I-contents. Geogenic salt influences in the form of NaCl increase the I-contents to 50 … 100 μg/l. Anthropogenic influences in the residential area and due to waste increase the Cl?- and I?-concentrations. There were not detected any dependences between the I- and NO3-contents.  相似文献   

9.
Trace metal clean sampling and analysis techniques were used to examine the temporal patterns of Hg, Cu, and Zn concentrations in shallow ground water, and the relationships between metal concentrations in ground water and in a hydrologically connected river. Hg, Cu, and Zn concentrations in ground water ranged from 0.07 to 4.6 ng L−1, 0.07 to 3.10 μg L−1, and 0.17 to 2.18 μg L−1, respectively. There was no apparent seasonal pattern in any of the metal concentrations. Filtrable Hg, Cu, and Zn concentrations in the North Branch of the Milwaukee River ranged from below the detection limit to 2.65 ng Hg L−1,0.51 to 4.30 μg Cu L−1, and 0.34 to 2.33 μg Zn L−1. Thus, metal concentrations in ground water were sufficiently high to account for a substantial fraction of the filtrable trace metal concentration in the river. Metal concentrations in the soil ranged from 8 to 86 ng Hg g−1, 10 to 39 μg Cu g−1, and 15 to 84 μg Zn g−1. Distribution coefficients, KD, in the aquifer were 7900,22,000, and 23,000 L kg−1 for Hg, Cu, and Zn, respectively. These values were three to 40 times smaller than KD values observed in the Milwaukee River for suspended particulate matter.  相似文献   

10.
Analysis of hexane-extractable hydrocarbons in zooplankton collected off Bermuda in August 1979, and their faecal pellets, gave an estimated removal rate of hydrocarbons from surface waters by ‘grazing’ of 16–46 μg m?2 for a 4 h period. With a number of assumptions, this can be translated to 8–23 mg m?2 yr?1. When compared to the annual input due to petroleum discharge in the currents feeding the Sargasso Sea (18–70 mg m?2 yr?1 hexane-extractable hydrocarbons), this result implies that zooplankton are an important factor in the short-term removal of petroleum residues from open ocean surface waters.  相似文献   

11.
Glucose uptake in lake water samples has been determined with short-time14C-experiments at different additions of the single heavy metals Cu++, Zn++, Cd++, Pb++, Hg++ and at different additions of a combination of all metals. The degree of a metal induced inhibition of glucose uptake varied from lake to lake and from season to season, whereby the addition of legally tolerated concentrations of 10 μg Cu/l and 200 μg Zn/l inhibited glucose uptake in most samples significantly, as well as the simultaneous addition of all metals. The legally tolerated limit of 1 μg Hg/l inhibited glucose uptake in Lake Lucerne samples almost completely, showed however no effect in samples of Lake Baldegg. The equimolar toxicity sequence of heavy metals for heterotrophic microorganisms has been determined as: Hg>Cu>Cd>(Zn. Pb). Glucose uptake of plankton sampled from metal polluted limno-corrals was less inhibited than that of the control plankton, when heavy metals were added to the samples singly or in combination. It is assumed that this effect is due to the natural selection of more resistant plankton species.  相似文献   

12.
The effect of short-term exposure to high concentration (mg l.?1) of water soluble fraction of aromatic heating oil on subsequent egg production by the estuarine copepod Eurytemora affinis has been studied in laboratory cultures to investigate possibly sublethal biological effects following exposure to hydrocarbon under an oil spill. Significant reduction in subsequent length of life, total number of eggs produced, mean brood size, and rate of egg production was observed. Exposure to naphthalene alone at 1 mg l.?1 for 24 h produced a significant effect on total fecundity of the females. Ingestion rates were significantly lower when measured in the presence of the water soluble fraction, and also naphthalene alone at mg l.?1 concentrations. Exposure to low-levels (10 and 50 μg l.?1) of 14C-naphthalene alone over a period of ten days produced no significant effect on feeding or reproduction despite the high concentrations of hydrocarbon accumulated during this period. The results are discussed in relation to previous work on the fate of hydrocarbons in planktonic copepods, using 14C-1-naphthalene as a model compound.  相似文献   

13.
The concentration levels of Cd (25 ng l?1), Cu (0.45 μg l?1), Ni (0.48 μg l?1), Fe (0.2–7.0 μg l?1), Pb (40 ng l?1) and Zn (0.80 μg l?1) have been determined in the Danish Sounds and in the Kattegat. Different sampling techniques have been used and analyses have been carried out separately by two different investigators, both using freon-extraction followed by determination by atomic absorption spectrometry (a.a.s.). Except for iron, found mainly in the particulate phase, the metals are found predominantly in a dissolved and labile (extractable) form. The results are compared with trace metal levels found in the two main water masses entering the Kattegat—the North Sea and the Baltic Sea.  相似文献   

14.
The Northern Adriatic is one of the most productive regions of the Mediterranean, primarily due to the eutrophicating influence of Italian rivers, in particular the Po. In June 1977 unusually high phytoplankton standing crops (13 μg Chl a l.?1) occurred, together with extremely low dissolved oxygen concentrations in bottom waters (to 13%) which persisted for 4–6 months. Such conditions were associated with unusual climatic conditions creating increased discharge from the Po.The data indicate long term meteorological changes which may alter the biological characteristics of the region to a degree equal to, or exceeding, those created by anthropomorphic eutrophication.The 1977 data are presented, discussed, and contrasted with a 10 year data series.  相似文献   

15.
The behaviour of the detergent builder nitrilotriacetic acid (NTA) has been studied in the presence of a marine bacterial population potentially associated with a sewage discharge to coastal waters. Additions of 500 μg l?1 NTA were made over a period of 80 days and 7500 μg l?1 NTA over 40 days in both aerobic and anoxic environments. It was concluded that NTA was not degraded at either concentration under aerobic or anoxic conditions, despite the presence of a significant bacterial population under aerobic conditions. Possible effects of NTA recalcitrance and its accumulation in coastal marine waters are discussed.  相似文献   

16.
A static renewal toxicity test was conducted to evaluate the response of the copepod Acartia tonsa to bis(tributyltin) oxide (TBTO), the active compound of recently developed antifouling paints. Copepods were individually placed in test tubes containing 4 ml of 0.3, 0.5, 1.0, 1.7 or 3.0 μg l?1 TBTO with acetone and seawater. Thirty copepods were used for each treatment and control condition and all solutions were renewed daily. The 96-h LC50 was 1.0 μg l?1 with a 95% confidence interval between 0.8 and 1.2 μg l?1 TBTO. The 144-h EC50 was 0.4 μg l?1 TBTO which approaches concentrations recently measured in San Diego Bay. Some copepods exposed to 0.3 μg l?1 TBTO became moribund after six days.  相似文献   

17.
An investigation on the levels of mercury contamination in one species of the Cyanophyta, 14 species of the Rhodophyta, five species of the Phaeophyta and six species of the Chlorophyta from Penang waters indicated fairly low levels of bioaccumulated total mercury content. The bioaccumulated values ranged from below the detectable level to 0.35 μg g?1 except for Padina sp. 1 which demonstrated an amount equivalent to 1.025 μg g?1.These results indicate that the level of mercury contamination in the marine environment of Penang island falls within an acceptable range from the viewpoint of algal biodeposition.  相似文献   

18.
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19.
In the dimict lake Arend (5.1 km2, 146 hm3, 49.5 m zmax), nitrogen is production-limiting with concentrations below the detection limit during the production period. Phytoplankton achieves biomasses of up to 18 mg/l fresh matter, essential contributions being made by Aphanizomenon with 2 mg/l and Anabaena with up to 10 mg/l. Nitrogen fixation was measured by the ethine reduction technique (acetylene reduction) during periods of the occurrence of heterocystforming Cyanophyceae and achieved peak values up to 6.59 μg N2 · h?1 · l?1 or 14.87 m?2 · h?1 g N2 · m?2 · h?1. The rates of fixation show a safe correlation with the biomass of heterocyst-containing Cyanophyceae (r = 0.88), their development beginning at values below the N : P-ratio of 2.66.  相似文献   

20.
Quantitative beach sampling conducted after the S. W. monsoon season yielded average standing stocks of tar ranging from 5 to 2325 g m?1 of shoreline with overall average of 224 g m?1. Values are among the highest reported for any world area and show a trend of increasing levels of oil residues close to the Strait of Hormuz. Data support the premise that tanker deballasting is a major source of oil pollution on the Omani coast. Locally high levels were seen near offshore tanker loading facilities. Petroleum hydrocarbons in rock oysters increased in a south to north gradient consistent with beach tar observations. But relatively low hydrocarbon levels in biota coupled with observations of very little floating tar suggests that oil released in Omani coastal waters aggregates, sinks, and reaches the coast as heavy tar lumps. Except for elevated levels of Cd at two stations, heavy metal and chlorinated hydrocarbon concentrations were low compared to more industrialized world areas. Suggestions are made to improve the effectiveness of future pollution studies in the Gulf Region.  相似文献   

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