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1.
The “Tsesis” oil spill in October 1977 resulted in the release of over 1 000 tons of medium grade fuel oil in an archipelago in the brackish Baltic Sea. Considerable oil quantities reached the benthos by sedimentation. Within 16 d benthic amphipods of the genus Pontoporeia, as well as the polychaete Harmothoe sarsi Kinberg, showed reduction to less than 5% of pre-spill biomasses at the most impacted station. The clam Macoma balthica (L.) was more resistant, and showed little or no mortality, but was heavily contaminated by oil (about 2 000 μg g-1 dry wt total hydrocarbons). The meiofauna was strongly affected, with ostracods, harpacticoids, Turbellaria and kinorhynchs showing clear reductions in abundance, while nematodes, as a group, were more resistant. In the winter following the spill gravid Pontoporeia affinis Lindström females showed a statistically significant increase in the frequency of abnormal or undifferentiated eggs. Food-chain transfer of oil to flounder [Platichthys flesus (L.)] was indicated. Not until the second summer after the spill were the first signs of recovery noted at the most heavily impacted station: Amphipods, H. sarsi and harpacticoids increased and the oil concentrations in M. balthica decreased (to about 1 000 μg g-1). In the area where amphipods had been virtually eliminated, there was an unusually heavy recruitment of M. balthica, reaching 4 000 juveniles, of 1.5–2 mm length, per square metre, probably from settling in summer 1978. Three years after the spill Pontoporeia spp. biomass was still depressed in the most affected area, while H. sarsi showed normal biomass, and M. balthica abundance was inflated. Oil concentrations in M. balthica (about 250 μg g-1) and flounder were only slightly elevated and the oil could no longer be confidently ascribed to “Tsesis” origin, even using GC/MS-analysis. Recovery was thus underway, but the long lifespan of M. balthica implies that the disturbed community composition may persist for many years at this station. Full recovery is likely to require more than 5 yr and may take a decade or more. An effort to evaluate the accumulated monetary loss to fishery from the accident indicates that direct costs of shoreline cleanup and vessel damage were considerably greater.  相似文献   

2.
Metabolic changes and toxic effects in Crangon crangon (collected during summer 1989 near Helsingør, Denmark and at Kulhuse in the Isefjord) were observed during exposure to different arsenate concentrations. Survival, respiration, and concentrations of hemolymph glucose, muscle glycogen andadenine nucleotides were measured. C. crangon was very tolerant of arsenate; survival was only affected at arsenate concentrations >25 ppm. Small individuals (0.2 to 0.29 g wet weight) were less tolerant than medium-sized and large individuals (0.5 to 0.59 g and 0.8 to 0.89 g wet weight), e.g. at 50 ppm the LT50 for small individuals was 180 h compared to 343 h and 360 h in middle-sized and large individuals. The relation between size and toxicity is probably due to the change in surface/volume ratio. Under clean conditions the respiration of C. crangon showed a clear relation between routine MO2 (O2 in mlg-1 h-1) and wet weight (r2=0.89; P<0.001). During shortterm exposure to arsenate (10 and 50 ppm), the respiratory rates (MO2) seemed to decrease in a size-dependent manner. The concentrations of blood glucose and muscle glycogen did not change in response to arsenate exposure. The concentrations of adenylate phosphates were high and constant throughout the experiments. C. crangon had maximal adenylate energy charge (AEC) values of ca. 0.8. No decrease in AEC due to the exposure to arsenate was observed.  相似文献   

3.
The accumulation of cadmium was investigated in two species of oysters [Crassostrea gigas (L.) and Ostrea edulis (L.)] from the same environment and in oysters of the same species (O. edulis) from two different environments (contaminated and uncontaminated), under controlled laboratory conditions (33‰ salinity, 10°C, 100 μg Cd l-1) for up to 111 d in 1982. C. gigas accumulated cadmium twice as fast as O. edulis (1.07 vs 0.52 μg Cd g-1 wet wt d-1). Furthermore, O. edulis from an uncontaminated environment accumulated cadmium faster than O. edulis from a metal-contaminated environment (0.52 vs 0.34 μg Cd g-1 wet wt d-1). There was no effect of cadmium exposure on total soft-tissue copper and zinc concentrations. Investigation of cytosolic metal-binding using Sephadex G-75 gel-permeation chromatography indicated that binding to very low molecular weight ligands (MW<1000) accounted for>70% of the cytosolic zinc in all oysters and>40% of the cytosolic cadmium in all oysters except O. edulis from Conwy at 83 d. In copper-contaminated oysters, excess copper was also associated with very low molecular weight ligands. Intermediate molecular weight cadmium/copper-binding proteins (similar to metallothionein in molecular weight) were observed in the cytosol and were shown to differ between species in terms of their behavior on Sephadex G-75. Finally, the distribution of accumulated cytosolic cadmium in O. edulis from the contaminated environment was shown to have a unique distribution, i.e., there was no cadmium associated with high molecular weight cytosolic macromolecules. The data indicate that both genetic and environmental factors influence cadmium accumulation in oysters.  相似文献   

4.
When exposed to Prudhoe Bay crude oil in flowing seawater for 180 days, the small intertidal clam Macoma balthica showed behavioral, physical, physiological and biochemical changes. At a high concentration of oil in seawater (3.0 mg l-1) burrowing rate decreased, respiration rate increased, growth was inhibited, and very high mortalities resulted. The lowest concentration of oil in seawater (0.03 mg l-1) inhibited growth and caused reabsorption of gametes. One group of adverse oil effects which was related to sluggishness and disorientation of the clams appeared after a week of exposure to oil; another group related to a negative energy balance was not observed until 60 days. We conclude that chronic exposure of M. balthica to oil-in-seawater concentrations even as low as 0.03 mg l-1 will, in time, lead to population decreases.Please address requests for reprints to Dr. D. G. Shaw at the Institute of Marine Science  相似文献   

5.
T. L. Tan 《Marine Biology》1983,76(3):247-252
The marine cadmium-sensitive Acinetobacter CS 13 was grown in glucose-limited chemostats to study the chronic toxicity of CdCl2. Addition of 25, 50 or 100 μg Cd2+ l-1 caused disturbances of balanced growth. At the dilution rate (D) of 0.05 h-1 the washout rate (A) became constant at 84, 78 or 66 h after addition of 25, 50 or 100 μg Cd2+ l-1 The washout rates were calculated to be respectively 0.037 h-1, 0.039 h-1 and 0.077 h-1. At D=0.1 h-1, A became constant after 48, 42 and 36 h, and were the same as D for all three Cd concentrations. Acridine orange staining revealed that 99% of the cells fluoresced green (viable cells) and 1% red or orange (dead cells). However, under Cd stress the percentage of red and orange fluorescing cells increased up to 20%. At D=0.1 h-1, viable and direct cell counts always gave the same result. At D=0.05 h-1, however, viable cell counts were lower than direct cell counts after 2–3 d of Cd exposure. It is assumed that at D=0.05 h-1, a part of the cells appearing green was already Cd injured, but the true yellowish green colour was not identified. Decreasing cell densities were accompanied by increasing glucose concentrations. Cells accumulated Cd (0–25 μg Cd2+ l-1) in relation to exposure time and Cd concentration in the medium, but maximum Cd contents were the same, increasing from 5.5 or 5.7 μg g-1 dry wt in the control to 15 μg g-1 after 2–3 d (D=0.05 h-1) or 16 μg g-1 after 1–2 d (D=0.1 h-1).  相似文献   

6.
Effects of copper sulphate on a marine food chain were investigated in large tanks at Loch Ewe on the west coast of Scotland. The food chain consisted of phytoplankton, the bivalve Tellina tenuis da Costa, and O-group plaice (Pleuronectes platessa L). During initial months after settlement, T. tenuis siphons are an important food for juvenile plaice, which feed by grazing the siphon tips; these subsequently regenerate. Copper dose rates of 10, 30 and 100 μg Cu/1 were investigated; the distribution of added copper was monitored and its metabolic effects were determined. Copper levels in water, sand, in algae on tank walls, in T. tenuis shell and flesh, and in plaice muscle and viscera were measured by atomic absorption spectrophotometry. Copper accumulated in sand, T. tenuis flesh and shell, and plaice viscera. Accumulations were dose-dependent and in no case was a plateau concentration reached. Most of the added dose was taken up by the sand; accumulations in T. tenuis shell were small — less than twice background in all cases. High levels were found in T. tenuis flesh, where concentrations after 100 days were 270, 470 and 1100 μg Cu/g dry flesh for dose concentrations of 10, 30 and 100 μg Cu/1, respectively. The mean control concentration was less than 50 μg Cu/g dry flesh. There was no accumulation of copper in plaice muscle. Visceral accumulations after 100 days were 71, 147 and 567 μg Cu/g dry flesh for dose concentrations of 10, 30 and 100 μg Cu/1, respectively. The mean control level was 30 μg Cu/g dry flesh. The effect of copper on phytoplankton metabolism was investigated by measuring plant pigment levels and rates of primary photosynthetic fixation of C14-labelled bicarbonate. All dose concentrations reduced both the standing crop and the rate of photosynthesis per unit of chlorophyll a. The effects of copper on growth and condition of T. tenuis and P. platessa were investigated. All dose concentrations adversely affected T. tenuis condition (dry flesh weight for standard individual). The effect was most marked during deposition of winter reserves. In the absence of plaice predation, there was a decrease in the mean siphon weight for T. tenuis exposed to 30 and 100 μg Cu/1. For plaice, all dose concentrations of copper resulted in reduced growth, but there was no significant change in condition or biochemical composition. The ash weight of fish exposed to copper was significantly higher than for controls.  相似文献   

7.
In the Federal Republic of Germany, benzene is one of the most important basic materials for the chemical industry. Only a relatively small proportion of the pure benzene processed in the chemical industry is emitted into the environment (ca. 40t in 1991). But the substance is also a natural component of the crude oil in gasoline and is released during incomplete combustion or is formed out of other aromatic substances. The primary source of emissions, with more than 10,000 t/yr (approximately 85% of this from motor vehicles with Otto engines), is commercial motor vehicle transportation. Benzene concentrations in the environment are approximately <1 μg/m3 in rural areas, 20–30 μg/m3 near main roads (peak levels in highly urbanized regions with much traffic as high as approximately 100 μg/m3) and 7–15 μg/m3 in the vicinity of industrial polluters. It has not been possible to detect a specific trend over time during the last ten years. An increased exposure (approx. 350–27,000 μg/m3) is likely while filling the tank and within the motor vehicle (approx. 10–200 μg/m3) due to gasoline volatilization from pipes, etc. Compared to outdoor air, higher concentrations of benzene (approx, 2–11 μg/m3) are measured in the indoor air which contains additionally benzene from tobacco smoke, equipment, renovating work and heating. The primary exposure pathway of benzene in humans is inhalation. Apart from individuals with occupational exposure, smokers have the highest internal benzene burden. Measures undertaken during recent years to reduce the amount of emissions have been counteracted at least in part by the increase in motor vehicle traffic. Further measures to reduce the emissions or to change the transporttation policies must still be or have already been initiated.  相似文献   

8.
In a shallow, subtidal, siliceous sediment, benthic microalgal biomass (g chlorophyll a cm-3) is influenced by light and physical sediment dynamics. The microalgal community is relatively dense, despite adverse conditions (7.0 g chlorophyll a cm-3), and is able to respond rapidly to favorable conditions. Productivity of this community is significantly correlated (P0.05) with benthic light. In addition, productivity is influenced by temperature and bottom water NH4 + and PO4 -3 concentrations, especially as the concentrations fall to levels approaching the K s (halfsaturation constant) of the microalgal community. Metabolic activity in this environment is dependent upon a continuous supply of organic carbon. Temperature is significantly correlated with respiration rate, but other factors (e.g. biomass and organic matter supply) are important also. Community respiration responds to overlying phytoplankton productivity in the same manner as deep-water benthic environments. Bacterial enumeration using CFU (colony-forming units) does not measure accurately the number of in situ metabolically active bacteria.This research was supported by Energy Research and Development Administration Contract AT (11-1) 3279, US AEC Contract AT (11-1) GEN 10, P.A. 20 and NOAA Sea Grant No. 04-3-158-22.  相似文献   

9.
Stable carbon (δ 13C) and nitrogen (δ 15N) isotope (SI) values of sedimentary organic matter (SOM), seston and two dominant bivalves, Mytilus spp. and Macoma balthica, were studied at 18 stations along the European coast in spring and autumn 2004. Three main regions, the Baltic Sea (BS), the North Sea and English Channel (NS), and the Bay of Biscay (BB), were tested for possible geographic (latitudinal) differences in the SI values. In spring, only BS showed lower δ 13C values of seston and Mytilus spp., and higher δ 15N values of SOM, than NS and BB. No significant differences between the 3 regions were found in autumn. Irrespective of season and regions, Mytilus spp. was more 13C-depleted than M. balthica. δ 13C values of M. balthica, but not those of Mytilus spp., were significantly correlated with SOM. These results are consistent with differences in feeding behavior of Mytilus spp. and M. balthica, as the two species are known as obligatory-suspension and facultative-deposit feeders, respectively. In contrast, no differences in the δ 15N values of Mytilus spp. and M. balthica were found at individual stations, indicating the same trophic level of the two bivalves within the food webs. At some stations, irrespective of geographic location, both bivalves showed δ 15N values up to 18–20 ‰. These were two trophic levels higher than those found at the other stations, indicating local and/or episodic eutrophic conditions, probably due to waste water discharge, and the effectiveness of both Mytilus spp. and M. balthica as bio-indicators of anthropogenic eutrophication. Overall, our results suggest that pathways of energy flow from OM pools to dominant bivalves is more related to local environmental conditions than to geographic regions across the European coastline. This has implications for food web studies along the Atlantic coast because most of the values are consistent over a large area and show no significant differences. Therefore, the present study can be used twofold for the determination of trophic baselines and for the correction of the trophic position of consumers higher up in the food web in the case of differences in waste water discharge.  相似文献   

10.
R. Flindt 《Marine Biology》1971,9(3):224-227
Heart beats of unrestrained Carcinus maenas L. have been recorded by means of aspiration electrodes. The heart rate shows a clear dependence upon the oxygen content of the sea water under otherwise constant conditions. There is a high degree of correlation between heart rate and oxygen concentration in the range between 0 cm3 and ca. 6 cm3 O2/I sea water. From this point upwards no further dependence could be found. Very low (beneath 0.5 cm3 O2/I water) and very high (over 12 cm3 O2/I water) concentrations lead to arrhythmia and often to long lasting intervals in the heart beats. It is suggested that this correlation is due to the oxygen-dependent excitability of the neurones generating the beats in the neurogenic hearts of crustaceans.  相似文献   

11.
At two fixed stations in the Equatorial Atlantic Ocean (0°–4° W), the physical, chemical and biological properties of the euphotic layer were determined for 14 d (Station A: 5–18 February, 1979) and 13 d (Station B: 20 October–7 November, 1979), respectively. The stability of the water column allowed comparison of 3 different “systems”: (i) a well-illuminated and nitrate-depleted mixed layer; (ii) a chlorophyll maximum layer (chl a max) in the thermocline which is poorly illuminated (6.3% of surface irradiance); (iii) a well-illuminated but nitrate-rich (>0.9 μg-at l-1) mixed layer. In each layer the particulate organic carbon (COP), nitrogen (NOP) and phosphorus (POP) contents were measured and compared with the phytoplankton biomass. In the chlorophyll maximum layer, the phytoplankton biomass contributed significantly to the total particulate organic matter (between 55 and 75%). In the nitrate-depleted mixed layer, the results varied according to whether the regression technique [COP=f(chl a)] was used, or the chl a synthesis during the incubation of the samples. With the former technique, the phytoplankton carbon (C p) content appeared minimal, because the y intercept, computed using all the data of the water column, was probably overestimated for this layer. POP would be more associated with living protoplasm than with carbon and nitrogen in the three layers. In the chlorophyll a maximum layer it constitutes a valuable detritus-free biomass measurement, since 80% of the POP consist of phytoplankton phosphorus. The assimilation numbers (NA=μg C μg chl a -1 h-1) were high in all three layers, but the highest values were recorded in the nitrate-depleted mixed layer (NA=15 μg C μg chl a -1 h-1). In the chlorophyll maximum layer, light would be a limiting factor during incubation: between 1025 and 8.1024 quanta m-2 d-1 NA and light are positively correlated independant of nitrate concentration. The growth rates of phytoplankton (μ) were estimated and compared to the maximum expected growth rate. Our main conclusion was that despite very low biomass and nutrient content, the mixed layer was in a highly dynamic state, as evidenced by high rates of phytoplankton growth and short nutrient turnover times (1 d or less for PO-P4 in the mixed layer versus 3 d in the thermocline). The presence of nitrate in the water column allows the development of a higher phytoplankton biomass but does not increase growth rate.  相似文献   

12.
Anemonia sulcata Pennant absorbs and accumulates tritiated D-glucose dissolved in sea water in natural concentrations (80 μg/l). The rate of decrease of glucose concentration in the sea water can best be described by an exponential function, when the concentration of added glucose exceeds 20 to 25 μg/l. The glucose, absorbed through the ectoderm, is immediately metabolized. This is determinable experimentally by tritiated water which is emitted into the sea water. The rate of uptake estimated experimentally was in the range 3 to 4 μg glucose/g wet weight/h, whilst the rate calculated by V max (maximum absorption rate) was 20 μg/g wet weight/h. The concentration of free glucose in the tentacle tissue is greater by a factor of 105 than that of the medium in which absorption takes place. Absorption is temperature-dependent; the Q10 between 15° and 25°C exceeds 2; translocation is, therefore, energy-dependent. Absorption was diminished by inhibitors, especially by phlorizin. The actinians increase their energy reserves by absorption of glucose (and other dissolved organic substances). The energetic net profit by taking up glucose comprises up to 50% of the energy amount which is equivalent to the oxygen consumption.  相似文献   

13.
The effect of increasing cadmium concentration (10, 100 and 1000 μmol dm‐3) on the growth, leaf area, content of assimilation pigments, cadmium content and the regulatory ability of the tissue of maize plants was investigated.

The results obtained document, already after 6 days, a significant decrease of dry weight, reduction of leaf area, chlorophyll a and b as well as carotenoids in plants grown in the nutrient solution containing 1000 μmol dm ‐3 of cadmium. A highly significant inhibition of growth, leaf area and assimilation pigments in plants growing in the nutrient solutions with 100 and 10 μmol dm‐3 of cadmium was registered after 17 days of cultivation. In plants growing in the nutrient solution containing 100 μmol dm‐3 of cadmium a demonstrable reduction of the content of assimilation pigments was registered after 11 days of culture.

With increasing cadmium concentration in the nutrient solution as well as in the plant tissue after 6 and 17 days of culture both the range of the regulatory zone and the extent of optimum pH increased into the acid region. The pH values of the isoelectric point decreased with increasing cadmium content in the solution.  相似文献   

14.
K. Gocke 《Marine Biology》1975,33(1):49-55
In summer, 1973, a short-term study with frequent sampling was performed in the Kiel Fjord (FRG). Temperature, salinity, number of viable bacteria, maximum uptakevelocity of glucose and acetate, concentrations of chlorophyll a, labile organic substances and ammonia and phosphate were measured. Strong variations in all parameters during short periods of time could be demonstrated. The number of viable bacteria fluctuated between 26x106 and 195x106 bacteria/l. Changes in the maximum uptake-velocity (V m ) of glucose between 0.23 and 0.85 μg C l-1 h-1 and in the V m of acetate between 0.36 and 2.40 μg C l-1 h-1 were recorded. A highly significant correlation between the number of viable bacteria and the maximum uptake-velocity of the two solutes was found. It is assumed that, at least for this area, at certain times the plate counts represent a major part of the active bacteria flora.  相似文献   

15.
The phytoplankton uptake and release rates for inorganic phosphate, dissolved organic phosphate and polyphosphate were estimated during 5 cruises on the Chesapeake Bay over a 9-month period. Phosphorus in all pools turned over in several minutes to 100 h, and each soluble pool appeared to contain fractions which were metabolically useful to the phytoplankton. Maximal uptake rates (V m ) for orthophosphate ranged from 0.02 to 2.95 μg-at P (1.h)-1 with half saturation constants (K s ) between 0.09 and 1.72 μg-at P l-1. At low soluble reactive phosphorus concentrations, the uptake rate of trace 32P orthophosphate was initially rapid, but declined after 15 to 60 min incubation. The data suggest that the initial uptake phase was dominated by exchange of 32PO4 for 31PO4 in the membrane transport systems whereas the subsequent phase represented the net incorporation of orthophosphate into phytoplankton cells.  相似文献   

16.
Discharges of nutrients, urea, dissolved organic matter and heavy metals by a sewage underwater pipeline are analysed in comparison to environmental conditions in a shallow coastal zone. Variable thermo-haline stratifications of the water column and currents in upper (2.62–34.97 cm s?1) and deeper (0.83–10.91 cm s?1) layers drive vertical diffusion and lateral transport of wastewaters. Loads of reactive phosphorus (0.13 tons d?1) and ammonium (1.62 tons d?1) by the pipeline are not negligible compared to the major river loads in the gulf. High concentrations of urea (≤11.51 μmol N dm?3) were found in the area of wastewater release. Ammonium uptake (6.14–534 nmol N dm?3 h?1) strongly exceeded nitrate uptake (0.19–138 nmol N dm?3 h?1), indicating that discharges of ammonium by the pipeline are actively assimilated by plankton community even at low levels of light. Distribution of Zn (≤27.7 ppb), Cu (≤25.6 ppb), Cd (≤0.80 ppb) and Pb (≤13.5 ppb) in the water column and the measurement of their complex-forming capacity in seawater did not indicate a persistent perturbation of the pelagic environment due to heavy metals.  相似文献   

17.
Daily compensation irradiation for net photosynthetic rates (ΣI comp) of Skeletonema costatum (Greville) Cleve, Chaetoceros ceratosporum Ostenfeld, Nitzschia sp., Thalassiosira nordenskiöldii Cleve, and Chroomonas salina (Wislouch) Butcher were measured during 1979 to obtain values for use in ecological models describing compensation and critical depths of marine phytoplankton. Batch cultures of these unicellular algae were exposed to temperatures and photoperiods varying from 6° to 15°C and 8.4 to 16.0 h, conditions typical of surface water in Saanich Inlet, a fjord in Vancouver Island, British Columbia, Canada. Results obtained with S. costatum and T. nordenskiöldii provided estimates of ΣI comp varying between 1.8 and 13 J cm-2 d-1, from which a mean value of 7.0 J cm-2 d-1 was calculated for use in ecological models with neritic phytoplankton. No seasonal variation in compensation irradiation was noted because photosynthetic efficiencies, which increased as division rates increased, were balanced by respiration rates, which increased as temperature increased. Results obtained with Chaetoceros ceratosporum, Nitzschia sp., and Chroomonas salina were difficult to interpret, because respiration rates were stimulated and depressed by light, respectively, for the first two species and the last one. This light effect was greatest when cells grew under conditions of low temperature and short photoperiod. Also, under winter and spring conditions, cells of Nitzschia sp. appeared to fix CO2 in the dark and with low irradiances by mechanisms other than photosynthesis.  相似文献   

18.
Abstract

Analyses were made of heavy metals, manganese, nickel, copper, zinc and lead in water samples and soft body, shell and different tissues (gills, digestive glands, mantle and viscera) of the Unionid mussel, Lamellidens marginalis collected from two tributaries of the Cauvery river. Water samples from Station I contained higher concentrations of the metals than those from Station II. the concentration of metals in water at both stations were in the descending order: Mn > Zn > Pb > Ni > Cu. However, the concentrations of metals in the soft body were in the descending order: Zn > Mn > Pb > Ni > Cu at both stations in all size groups of mussels tested. the concentration of zinc maintained a linear relationship with the size of the mussels, but manganese showed a reverse trend. Small size (4-5 cm) mussels accumulated more manganese (105.5 μg.g?1 dry wt.) than larger ones (7-8 cm; 6.5 μg.g?1 dry wt.). Both young and old is accumulate the same level of lead, copper and nickel in the soft body. the order of concentrations of metals (Mn, Pb, Zn, Ni and Cu) in the shell of mussels from both stations coincided with the order of concentrations of background water except for lead. the accumulation of lead was higher in shell (30.4-36.2 μg.g?1 dry wt.) than in soft body (6.4-12.0 μg.g?1 dry wt.). the pattern of concentration of metals in the various tissues reveal that the digestive glands have greater ability than other tissues to concentrate most metals under study. the concentration factors for soft body, shell and different tissues are presented. the advantages in using the common mussel for biomonitoring of contaminants in water is also discussed.  相似文献   

19.
Latitudinally separate populations of the sea anemone Metridium senile (L.) are very similar genetically by electrophoretic criteria, yet respond differently to temperature. Anemones from southern and northern California (USA) have different oxygen consumption patterns in response to acclimatory and acute changes in temperature. Northern anemones show a pronounced increase in Q10 at temperatures just above the normal environmental range, but southern anemones do not. The two populations also differed in the extent of metabolic compensation to temperature following several weeks of acclimation. This acclimation regime resulted in changes in the activities of several enzymes of intermediary metabolism, yet the extent and direction of these changes did not display a consistent trend with regard to acclimation temperature or population. The biochemical concomitants of acclimatory and acute temperature effects were studied further by measuring the concentrations of adenylates (ATP, ADP, and AMP) in anemones from the two populations exposed to different temperature regimes. During cold acclimation for several weeks, total adenylate concentrations (AT) increased in both the southern and northern populations, possibly due to metabolic rate compensation, since AT is positively correlated with tissue metabolic rate in many species. Moreover, the extremely low weight-specific oxygen consumption rates of M. senile are probably related to its very low AT values. Acute temperature decreases had no effect on adenylate concentrations and adenylate energy charge (AEC); in contrast, acute temperature increases led to large changes in adenylate concentrations. The effects of starvation on adenylate concentrations are pronounced, and the effect is temperature-dependent. In starved individuals held at 20°C, AEC values fell to 50% of normal values after 8 d, while those held at 10°C maintained normal AEC values.  相似文献   

20.
Abstract

Sea urchins (Paracentrotus lividus) were collected from the Mediterranean coast off Alexandria, Egypt and the Atlantic coast of Ireland to the west of Galway. Samples of another urchin species, Psammechinus miliaris, were collected from the entrance to Southampton Water, U.K. Both the Alexandria coast and Southampton Water receive domestic and industrial waste water inputs whilst the western Irish coast is relatively unpolluted.

Sampled animals were dissected to separate coelomic fluids, Aristotle's lantern, gonads and tissue (digestive tract plus connective tissue). the concentrations of heavy metals (cadmium, copper, lead, nickel and zinc) in the different parts were measured using flame atomic absorption spectroscopy.

Many levels of heavy metals in the different parts were similar in specimens taken across the wide range of sites and the two species. A notable exception was the high level of copper (33 μg g?1 dry wt.) and zinc 328 μg g?1? dry wt.) in urchin tissue from Southampton Water.

The metal concentrations in the gonads of Paracentrotus lividus are of particular interest because of human consumption of this species. the highest levels of copper (3.3–5.2 g?1? dry wt.) and zinc (74–181 μ g?1? dry wt.) dry wt.) in gonads were found in the samples from Egypt. Data from this study are compared with other results reported from the Mediterranean.

A simple, short term, elevated water column copper uptake experiment was undertaken with Paracentrotus lividus which showed an increase in gonad concentrations of this element.  相似文献   

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