共查询到20条相似文献，搜索用时 15 毫秒
1.
Behavioural responses to chlorinated seawater were studied in the laboratory using eight species of fish (topsmelt, Atherinops affinis [Ayres]; pile perch, Rhacochilus vacca [Girard]; señorita, Oxyjulis californica [Günther]; blacksmith, Chromis punctipinnis [Cooper]; northern anchovy, Engraulis mordax [Girard]; opaleye, Girella nigricans [Ayres]; bluebanded goby, Lythrypnus dalli [Gilbert] and mussel blenny, Hypsoblennius jenkinsi Jordan and Evermann) which occur near the Units 7 and 8 discharge of Southern California Edison's Redondo Beach Steam Generating Plant in King Harbor, California, USA. All species except Engraulis demonstrated prolonged avoidance of chlorinated quadrants of the behaviour chamber. The avoidance thresholds were species-specific and species totally avoided estimated total residual oxidant (TRO) concentrations from 0·094 to 0·456 mg/litre. Calculated significant avoidance thresholds averaged 0·066 mg/litre TRO; young Atherinops significantly avoided TRO concentrations as low as 0·028 mg/litre (p < 0·001). The highest avoidance thresholds were exhibited by sedentary species and were modified by the presence of cover inside the behaviour chamber. The avoidance response protected against mortality in all species except Lythrypnus and Engraulis. 相似文献
2.
G. Roesijadi D.M. Jacobsen J.R. Bridge E.A. Crecelius 《Marine environmental research》1979,2(1):71-84
Exposure of the crab Cancer productus to chlorinated seawater resulted in alterations in haemolymph sodium and magnesium concentrations. At the highest chlorination levels, which approached the 96-h LC50, regulation of both ions was essentially abolished. Reciprocal changes in the sodium and magnesium levels suggested an effect on the activity of the bladder wall, which has been implicated in the regulation of haemolymph magnesium in crustaceans.Additionally, exposure to 1·19 μg/ml applied Cl (0·68 μg/ml TRO) for 96 h resulted in a fourfold increase in the ammonia excretion rate. Crabs also contributed considerable chlorine demand to the exposure seawater. Measurements of TRO in the inhalant seawater and water exiting the crabs' branchial chambers indicated a reduction in TRO equivalent to 57% of that initially present in the inhalant water (0·51 μg/ml TRO).Measurements of ammonia concentrations in the exposure water indicated that ammonia in seawater was consumed in reactions with oxidants. This was especially evident at higher levels of chlorination. At 0·58 μg/ml applied Cl and above, chlorination resulted in near disappearance of ammonia from the water. 相似文献
3.
Bioassays were conducted with sea urchin and sand dollar sperm to determine the toxicity of chlorinated and unchlorinated sewage effluent and chlorinated and brominated seawater. The sperm cells were exposed to seawater dilutions of each toxicant for 5–15 min. The fertilisation of eggs served as the indicators of sperm viability. The effective concentrations which reduced fertilisation success by 50% (EC50) averaged 2·2 and 4·8% chlorinated and unchlorinated sewage in seawater, respectively. The sperm cells were extremely sensitive to chlorinated seawater at concentrations from 0·002 to 0·020 mg/litre total residual oxidant (TRO). Brominated seawater proved toxic to sperm in one test at 0·015 mg/litre TRO. Results of the sperm bioassays are compared with previous acute and chronic bioassays with fish. 相似文献
4.
《Marine environmental research》1987,23(1):49-64
The bivalves Protothaca staminea and Mytilus edulis were exposed to five depths of decomposing bark from an active log transfer facility for 13–96 days in a field experiment at Auke Bay, Alaska. Survival and condition of both species was inversely related to depth and duration of bark coverage. As little as 6 cm of bark reduced survival; survival declined most rapidly between 10 and 15 cm of bark. The depths of bark under which half the animals died after 96 days of exposure were 12·8 ± 1·6 cm for P. staminea and 10·9 ± 1·5 cm for M. edulis. Interstitial water in the bark deposits had low concentrations of dissolved O2 (2·5–5·3 mg/liter) and elevated concentrations of hydrogen sulfide (1·0–8·1 mg/liter total sulfide) and ammonia (46–131 μg-at N/liter) compared to the surface water from the control treatment. Survival of P. staminea and M. edulis was inversely related to concentrations of hydrogen sulfide and ammonia and directly related to dissolved O2 concentrations. 相似文献
5.
To determine if avoidance of chlorinated seawater by fish resulted in physiological protection from toxicity, studies were carried out which assessed (a) changes in the routine oxygen consumption rate and (b) the ability of treated fish to successfully compete with untreated conspecifics for a limited food resource.Temperate marine damselfish, Chromis punctipinnis, were exposed to stepwise increasing levels of chlorinated seawater in a behaviour chamber and avoided total residual oxidant (TRO) levels greater than 0·15-0·16 mg/litre. Cumulative exposures ranged from the equivalent of 0·38-5·23 in at 1·0/litre TRO. One day after exposure, routine oxygen consumption rates were decreased by 25 to 45% from pre-exposure rates and were correlated with the cumulative oxidant exposure. One month post exposure, respiration rates returned to pre-treatment levels. This transient depression of the respiratory rate did not affect survival or growth of chlorine-treated fish which were forced to compete with untreated conspecifics for a restricted food supply. 相似文献
6.
Three species of estuarine invertebrates, Palaemonetes pugio (grass shrimp), Pagurus longicarpus (hermit crab) and Argopecten irradians (bay scallop), were exposed to Cd in flowing seawater at concentrations of 0·06, 0·12, 0·25, 0·5 and 1·0 mg/litre. Incipient LC50 values of 0·53 and 0·07 mg/litre were estimated for bay scallop and hermit crab, respectively. The toxicity curve for grass shrimp had not stabilised, but the incipient LC50 value was estimated to fall within a range of 0·2 to 0·3 mg/litre. Short-term response, as measured by time to 50% mortality at the highest Cd concentration, was 10, 21 and 23 days for the bay scallop, hermit crab and grass shrimp, respectively. Scallop growth was inhibited at all exposure concentrations with a measured 42-day EC50 value of 0·078 mg/litre Cd. Byssal thread detachment precedes death in bay scallops. An EC50 value of 0·54 mg/litre Cd for byssal detachment was measured on day 8 of the bioassay before appreciable mortality. This compared favourably with the incipient LC50 value of 0·53 mg/litre Cd. Cadmium accumulation occurred at all concentrations in bay scallop and grass shrimp. 相似文献
7.
《Estuarine, Coastal and Shelf Science》1987,25(1):127-133
The response of the exoproteolytic activity of seawater to proteolytic inhibitors suggests that metalloproteases are the main enzymes involved. The Km of exoproteolytic enzymes for the hydrolysis of indigenous proteins in coastal north seawater has been evaluated as 80 μg l−1 and the maximum rate of proteolysis lies in the range 0·1–0·35 μgC l−1-enzymatic-unit−1. Enrichment experiments suggest that both species selection and metabolic regulation may play a role in the exoproteolytic activity/biomass ratio. However, in situ exoproteolytic activity/biomass ratios observed in a broad range of natural marine environments lie in a very narrow range, which is intermediate between those observed after amino acid or protein enrichment. 相似文献
8.
In order to characterize our study area and to provide reference values to be used in the future to measure the changes produced by an increase in contamination, the concentrations of chlorinated hydrocarbons have been investigated in fifty-one samples of seawater, taken at four different depths: air-sea interface, surface, one metre and bottom waters, and in twenty-three samples of surface sediments from Blanca Bay, Argentina. Of eleven organochlorine compounds we were looking for (α BHC, lindane, heptachlor, δ BHC. aldrin, heptachlor epoxide, dieldrin, o-p′DDD, p-p′DDD, o-p′DDT and p-p′DDT), seven could be detected in seawater and three in surface sediments with the following mean concentrations: α-BHC=48·2 ng l?1; lindane=54·2 ng l?1; heptachlor=45·0 ng l?1; δ BHC=12·5 ng l?1; aldrin=61·8 ng l?1 and ΣDDT=67·0 ng l?1; and δ BHC=3·2 ng g?1; lindane=4·2 ng g?1 and heptachlor=1·0 ng g?1 for seawater, regarding the surface waters, and sediment samples, respectively.Concentration factors among the different water layers were also studied to see if there was any correlation between chlorinated hydrocarbon contents and the water depths from which the samples were taken. As a mean value, the air-sea interface water contains 18 times more of these compounds than that of the water near the bottom. A comparison of the values corresponding to seawater and surface sediments from our study area with those levels measured in samples from other geographic locations is also presented.With the purpose to detect a relationship between chlorinated hydrocarbon concentrations and the contents of particulate matter (PM) on the one hand, and particulate organic material (POM) on the other hand, four groups of samples containing different amounts of PM and POM, respectively were formed. From a comparison of the results obtained, lindane, heptachlor and δ BHC showed a tendency to lower concentrations in those samples containing little PM whereas α BHC and aldrin remained without important changes. No significant correlation was found between organochlorine levels and contents of POM. 相似文献
9.
The effects of ozone-produced oxidants (OPO) on three developmental stages of the American oyster, Crassostrea virginica, were evaluated. Both straight-hinge (48-h post fertilisation) and setting pediveliger larvae were exposed to a series of OPO concentrations ranging from 0·05 to 0·30 mg/litre OPO (as total residual chlorine) at 25°C for 96 h. Mortality was used as the response parameter and results were quantitatively compared with the effects of chlorine-produced oxidants (CPO) obtained from the literature on these same developmental stages. Adult oysters (2- to 4-year class) were exposed to OPO concentrations ranging from 0·01 to 0·50 mg/litre at 15°C for 5 days and to the same concentration range at 25°C for two consecutive 6-day periods. Shell deposition and faecal matter accumulation were used as the response parameters for this stage.Straight-hinge larvae were significantly more sensitive to OPO than setting pediveliger larvae. Both larval stages were significantly more sensitive to CPO than to OPO. Shell deposition was significantly inhibited at all OPO concentrations for both 15°C and 25°C acclimated adult oysters. No significant differences were found between the shell deposition response of oysters at the two acclimation temperatures. Faecal matter accumulation was significantly reduced at OPO concentrations ≥ 0·05 mg/litre at both 15°C and 25°C. It was significantly (p < 0·05) greater for 25°C acclimated oysters than for 15°C acclimated oysters at OPO concentrations < 0·10 mg/litre but not at higher concentrations. 相似文献
10.
M.S Harakeh Aftim Acra May Jurdi Yester Karahagopian 《Marine environmental research》1985,16(1):13-22
The muscle tissue of 266 fish caught along the coast of Lebanon from Beirut to Tyre (85 km) were analysed for total mercury content. The mean levels for the 13 species ranged from 0·028 mg/kg of wet tissue for Siganus rivulatus to 0·0.54 mg/kg for Mullus barbatus. Whereas no significant differences (P < 0·05) in mercury levels were noted between species, in most cases a direct relationship was found between the weight or length of fish of the same species and total mercury content. Similarly, there were no significant differences (P < 0·05) between herbivore and carnivore species, nor between resident and migrant ones. All of the values obtained in the present study fall below the widely accepted limit of 0·5mg/kg of edible tissue. 相似文献
11.
Morris H. Roberts 《Marine environmental research》1980,3(1):63-80
The acute toxicity of chlorinated and bromochlorinated treated sewage waste was determined with spot, Leiostomus xanthurus. The halogenated sewage waste was generated in a pilot plant located at the James River Sewage Treatment Plant, Newport News, Va. The 96 h and 144 h LC50's were 0·23 mg/l (measured residual) for chlorine and 0·25 mg/l (measured residual) for bromine chloride. These concentrations are considerably higher than those which would be produced by optimal halogenation rates for disinfection or maximum superhalogenation rates permitted by pilot plant equipment and normal effluent dilution rates. 相似文献
12.
Measurements were made of chlorophyll-a and phaeophytin-a in calcareous sediments along transects off the east coast of Florida (75–190 m) and the west coast of Grand Bahama Island (170–300 m). Solvent partitioning showed that chlorophyll-a concentrations never exceeded 0·1 mg m?2 at either location, most as degradation products. Total pigment concentrations (chlorophyll and phaeopigments) ranged from 0·18–1·83 mg m?2 in sediments off Grand Bahama Island and 2·50 to 20·65 mg m?2 off West Palm Beach. Pigments, expressed per gram dry weight of sediments, increased with depth across the Florida Continental Shelf. This is probably due to differences in sediment character between near-shore and off-shore sediments. 相似文献
13.
《Marine environmental research》1986,19(2):115-129
Orchestia gammarellus (Pallas) will tolerate temperatures from 0°C to c. 30°C but dies in < 1 h at 35°C. Both small and large animals survive > 96 h in water (aerated) between 1 and 60%(.) salinity. In distilled water and 100%(.) brine death occurred after 8–24 h. In fully saline water, pH reduction to c. 3·3 is tolerated. Highly alkaline (pH 11–13) conditions in low salinity media are rapidly fatal. Ammonium concentrations (in fully saline water) some five orders of magnitude higher than normal for seawater are tolerated, reflecting the enhanced ammonium concentration encountered in rotting weed beds. Cl− ion concentration equivalent to that in normal seawater will not support O. gammarellus in the absence of Na+ ions. High NO3− concentrations (> 100 mg NO3− litre−1) are fatal in < 24 h. A large range of NaCl concentrations is tolerated (one to two orders of magnitude dilution) by immersed animals. Animals will live longer in air, however, when fed low Na+ food than when immersed in seawater diluted to an equivalent ion strength. Ca2+ and K+ ions cannot substitute for Na+. Orchestia gammarellus will, however, tolerate wide variations in the ratio of Na+:K+ ions (i.e to a shift from 30:1 to 0·3.1) in hypo-osmotic media. At 10°C it will survive c. 5 h of anoxia. It will penetrate into strongly reducing conditions (− 318 mV) even with access to better oxygenated conditions. In nature, behavioural avoidance probably ensures that O. gammarellus does not encounter many of these parameters at acutely limiting values. That this species is so tolerant, however, bears on the evolutionary adaptability of talitrid amphipods to non-marine conditions. Desiccation sensitivity and Na+ ion dependency are the species' most important barriers to life on land. 相似文献
14.
Concentrations of zinc, manganese, copper, cadmium, magnesium and iron in three species of red, four species of brown and three species of green macroalgae, and also in sea water have been determined at two localities along the coast of Aqaba. Significant differences in metal concentrations were found between the various species (P<0·01). Similar significant differences were found with regard to different metals (P<0·001). Concentration factors ranged between 102 for Cd and 9·2 × 104 for Fe. The difference in levels of metals between the two localities, however, was not significant (P > 0·05). Of the three groups of algae examined, rhodopytes exhibited the highest concentration power of metals. 相似文献
15.
The soft sediment fish communities below 20 m depth were studied at two sites on the west coast of Scotland (Irvine Bay, Firth of Clyde and the Lynn of Lorne) using small meshed beam trawls. In both cases the emphasis was on the small demersal fish (<15 cm) within these communities. The Irvine Bay community was studied between May 1978 and December 1979 and the Lynn of Lorne community between February 1975 and October 1976.Twenty-seven fish species were recorded in Irvine Bay and 32 in the Lynn of Lorne. In both communities four species constituted more than 78% of the total annual abundance, two gobies (Lesueurigobius friesii and Pomatoschistus norvegicus) were high in the dominance ranking for both sites. The species abundance lists were similar for both sites (0·62 level of similarity) but the species lists for each site were different (0·36 level of similarity). The overall mean density of small demersal fish was similar for both sites (Irvine Bay = 0·045 individuals m?2 and the Lynn of Lorne = 0·047 individuals m?2). There were two periods of high abundance for both communities (late autumn to winter and late spring). There was, however, a low repeatability between successive years. The species richness (D) was relatively high (Irvine Bay = 1·5-3·08, Lynn of Lorne = 1·4-3·34) as was the species diversity (H′) (Irvine Bay = 1·17-1·97, Lynn of Lorne = 1·23-1·95). The proportional representation () of each species within the community was greater in Irvine Bay ( = 0·57-0·77) than in the Lynn of Lorne ( = 0·50-0·72). Therefore these two communities of small demersal fish appeared to be similar at the community level but the way in which this was achieved was different. 相似文献
16.
The bivalve molluscs Mytilus californianus and Crassostrea gigas were exposed to filtered seawater containing the isotope 95mTc added as pertechnetate (TcO4?) to study the biokinetic behaviour of this element. Whole body concentration factors for both organisms at equilibrium were small (CF = 1·3–1·5); individual organ concentration factors were highest for the visceral mass in both. Loss rates determined both in the laboratory and under field conditions were biphasic for both molluscs; initial loss of Tc was rapid with slightly more than 50 % of the initial label being lost within 10 days. Thereafter, loss rates decreased and whole body biological half-lives ranged from 80 to 134 days. Neither I? nor IO3? affected the uptake of Tc by M. californianus even when concentrations of these anions exceeded those normally present in seawater by two orders of magnitude. 相似文献
17.
Mercury, cadmium, copper and zinc concentrations in brain, liver, kidney, heart and spleen of twenty-six specimens of the common porpoise (Phocoena phocoena) are presented. Mercury and cadmium levels in liver and kidneys tended to increase with length of animal, but copper and zinc levels show no such trends. The proportion of methylmercury to total mercury (9%–57%) in the liver decreased with increasing total mercury concentrations. Lead, chromium, nickel and cobalt levels were below the analytical detection limits (0·5, 1·0, 1·0 and 2·5 μg?1, respectively). 相似文献
18.
The addition of stock copper and zinc nitrate solutions to filtered seawater (pH 7·91) resulted in a large pH shift which was more pronounced with copper. The pH shift was minimized by increasing the buffering capacity of seawater using 10 mm Tris-Tes pH 7·91. Subsequent experimentation was carried out in both unbuffered and buffered seawater.In unbuffered seawater, both copper and zinc had a pronounced inhibitory effect on Mytilus edulis sperm respiration with 50% inhibition occurring at 0.65 mm (41·3 ppm) copper and 1.0 mm (65·4 ppm) zinc. Egg respiration was also inhibited by copper with 50% inhibition occurring at 0.9 mm (57·2 ppm) whereas zinc inhibited egg respiration by only 30% at 1·5 mM (98·1 ppm).In buffered seawater, both copper and zinc produced an inhibitory effect on sperm respiration. However, with copper the inhibition was much reduced whereas zinc had tthe same inhibitory effect as in unbuffered seawater. In contrast to unbuffered seawater, egg respiration was stimulated by copper but zinc produced a comparable respiratory inhibition. The uptake of both copper and zinc in sperm and egg in buffered seawater increased with increasing metal concentration. Metal ion uptake, when expressed as ng ions μl cell volume?1, was approximately 3-fold greater in the sperm than in the eggs and in both cases zinc uptake exceeded copper uptake.At a seawater pH of < 7·5, in the absence of copper or zinc, the respiration of both egg and sperm was inhibited. The maximum levels of inhibition at pH 5·4 were 15% and 30% for sperm and egg, respectively.The differing actions of copper on egg respiration in buffered and unbuffered seawater appear to be due to enhanced copper uptake in unbuffered seawater. 相似文献
19.
Particulate nitrogen (PN) and chlorophyll a (Chla) were measured in the northern reach of San Francisco Bay throughout 1980. The PN values were calculated as the differences between unfiltered and filtered (0·4 μm) samples analyzed using the UV-catalyzed peroxide digestion method. The Chla values were measured spectrophotometrically, with corrections made for phaeopigments. The plot of all data was found to be non-linear, and the concentration of suspended particulate matter (SPM) was found to be the best selector for linear subsets of the data. The best-fit slopes of plots, as determined by linear regression (model II), were interpreted to be the N: Chla ratios of phytoplankton. The Y-intercepts of the regression lines were considered to represent easily-oxidizable detrital nitrogen (EDN). In clear water ( < 10 mg l?1 SPM), the N: Chla ratio was 1·07 μg-at N per μg Chla. It decreased to 0·60 in the 10–18 mg l?1 range and averaged 0·31 in the remaining four ranges (18–35, 35–65, 65–155, and 155–470 mg l?1). The EDN values were less than 1 μg-at N l?1 in the clear water and increased monotonically to almost 12 μg-at N l?1 in the highest SPM range. The N: Chla ratios for the four highest SPM ranges agree well with data for phytoplankton in light-limited cultures. In these ranges, phytoplankton-N averaged only 20% of the PN, while EDN averaged 39% and refractory-N 41%. 相似文献
20.
J.V. Leyendekkers 《Marine Chemistry》1974,2(2):89-110
A general equation is derived for predicting the partial molal volume (pmv) of an electrolyte in seawater, using binary solution data, and seawater density data. The composition of seawater need not be “average” - prediction can be made for any composition. Simpler equations are derived for “average” seawater. The ranges cover , t = 0–30°C and p = 1–1,000 bar, subject to the availability of binary solution data. Estimates of the pmv's of a number of electrolytes are made and compared with experimental values and the summed ionic values. 相似文献