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1.
Assessing toxicity of Lake Diefenbaker (Saskatchewan,Canada) sediments using algal and nematode bioassays 总被引:1,自引:1,他引:0
Lake Diefenbaker, on the South Saskatchewan River, Saskatchewan, Canada, receives, on average, 90% of its inflow from snowmelt and rainfall in the Rocky Mountains. The inflowing rivers also receive irrigation return flows and municipal and industrial effluents which may result in the contamination of lake sediments. The sediments were assessed by nematode and algal bioassays.The toxicity of five chemical fractions of the sediment was determined using the nematode Panagrellus redivivus as the test organisms. The results suggest that the sediment chemical fractions frequently inhibit growth and maturation, while lethality was observed at 4 of 12 sites.Samples from 3 of these sites were further evaluated using conventional elutriate Algal Fractionation Bioassays (AFB) with both natural Lake Diefenbaker phytoplankton and a mixed laboratory grown algal culture. The natural phytoplankton showed inhibition at sediment: water ratios of 10: 1; whereas the algal cultures showed both enhancement and inhibition. Evidently, the sediments are frequently toxic to the species tested except for the algal culture. The AFB assesses the mitigative and synergistic effects of contaminants and nutrients and being a conventional elutriate, is more realistic and potentially more acceptable than the chemical fractionation/nematode bioassay technique which essentially considers potential trace organic contaminant effects. 相似文献
2.
SUMMARY Water samples were collected from fourteen sampling points along the Hunyani River system and subjected to various filtration treatments involving glass fibre filters and 1,2 and 0,45 pm membrane filters. Chemical analyses of the filtered waters showed that nitrogen, phosphorus and iron were lost by different filtration treatments. Filtration by membrane filters led to a reduction of algal growth potential as demonstrated by algal bioassays using Selanastrwn capricornutum Printz as the test alga. Algal bioassays showed that biologically available phosphorus was primarily removed by the 1,2 μm membrane filter while biologically available nitrogen and iron was principally lost by filtration through the 0,25 μm membrane filter. A refined algal bioassay designed to determine the identity of limiting micronutrients found that all essential micronutrients were affected by membrane filtration. 相似文献
3.
Potential nitrogen limitation to chl a production in surface waters of Saronicos Gulf, Aegean Sea was assayed using the alga Pavlova lutheri as the test organism. The oligotrophic and eutrophic water types of this area were compared by in situ and in vitro chl a production estimations. Additions of ammonium alone as well as in combination with complete nutrient enrichment were made to the oligotrophic waters and the algal growth yield was determined and compared with the corresponding yield in unenriched water cultures. The results from routine nutrient analysis and bioassay experimentation support the view that nitrogen has a priority among the factors limiting phytoplankton growth in the Eastern Mediterranean Sea. 相似文献
4.
Ilkka Kortelainen 《Hydrobiologia》1994,294(3):207-213
Laboratory sediment bioassays, both acute and chronic, were conducted on sediment elutriates from the River Eurajoki, SW Finland. The river is under impacts of industrial discharges, community effluents and agricultural run-offs. The water flea Daphnia magna Straus was used as a test organism. None of the elutriates tested were acutely toxic. In a long-term bioassay sediment elutriates had effects on survival, body growth and reproduction. Elutriates prepared from samples of a downstream station were characterized by low survival, small body size, reduced total offspring production, and delayed start of reproduction. 相似文献
5.
The eukaryotic alga Ochromonas danica, a nutritionally versatile, mixotrophic chrysophyte, grew on phenol as the sole carbon source in axenic culture and removed the phenol carbon from the growth medium. Respirometric studies confirmed that the enzymes involved in phenol catabolism were inducible and that the alga oxidized phenol; the amount of oxygen consumed per mole of oxidized substrate was approximately 65% of the theoretical value. [U-14C]phenol was completely mineralized, with 65% of the 14C label appearing as 14CO2, approximately 15% remaining in the aqueous medium, and the rest accounted for in the biomass. Analysis of the biomass showed that 14C label had been incorporated into the protein, nucleic acid, and lipid fractions; phenol carbon is thus unequivocally assimilated by the alga. Phenol-grown cultures of O. danica converted phenols to the corresponding catechols, which were further metabolized by the meta-cleavage pathway. This surprising result was rigorously confirmed by taking the working stock culture through a variety of procedures to check that it was axenic and repeating the experiments with algal extracts. This is, as far as is known, the first definitive identification of the meta-cleavage pathway for aromatic ring degradation in a eukaryotic alga, though its incidence in other eukaryotes has been (infrequently) suggested. 相似文献
6.
Changes in epilithic algal communities colonizing introduced substrata were determined in a stream polluted with oil refinery
effluent at Digboi (Assam, India). The number of algal taxa was reduced but the growth of blue-green algae, particularly two
species ofOscillatoria, was encouraged. Epilithic biomass (as chlorophylla) also declined at polluted stations. The algal community of the upstream station was markedly different from the community
occurring just after the confluence of effluent; however, the differences were gradually reduced downstream, indicating improvement
in water quality. Of the various criteria tested for possible relationships with the level of pollutants, species richness,
Shannon diversity and biomass showed significant relationships. The study demonstrates the usefulness of algal criteria for
monitoring oil pollution in running waters. 相似文献
7.
T. M. Hübner S. Tischer H. Tanneberg P. Kuschk 《International journal of phytoremediation》2000,2(4):331-342
In constructed wetlands for the treatment of industrial effluents and in contaminated waterlogged soils, wetland plants (helophytes) are exposed to toxic chemicals. Hence, the plants' resistance to contaminants is an important prerequisite for applying phytoremediation to solve these environmental problems. For toxicity tests on the germination and growth of various helophytes (Phalaris arundinaceae and Phragmites australis), phenol, phenanthrene, and a mixture of both were used as examples of chemicals from the petrol- and coal-processing industries. The germination rate, shoot length, root length, and influence on leaves, young shoots, and dry weight were studied. Although an increase in contaminant concentration decreased plant growth (dry weight, shoot length); interestingly, the number of young shoots rose. Low contaminant concentration (about 50 mg/l in case of phenol) stimulated the plant growth. The cress seed germination test was less susceptible compared with plantlet exposure in the case of phenol and phenanthrene. Due to its low bioavailability, solid phenanthrene (without solutizer) did not significantly affect plant growth. 相似文献
8.
A. M. Hartley W. A. House M. E. Callow B. S. C. Leadbeater 《International Review of Hydrobiology》1995,80(3):385-401
The precipitation of calcite from a calcium bicarbonate solution, similar in ionic strength to natural hardwaters, was observed in a series of experiments utilizing an automated culture apparatus. Seeded growth experiments, using calcite seed crystals, were performed at a range of phosphate concentrations to observe inhibitory effects. These experiments demonstrated a linear relationship of increasing inhibition with increasing initial phosphate concentration. A further series of experiments was performed in which an actively photosynthesizing culture of a unicellular green alga (Chlorococcum sp.) was added to the culture vessel in order to initiate precipitation. Experiments to observe spontaneous precipitation, occurring in the absence of both seed and alga additions, were carried out to compare with precipitation rates in the algal experiments. A control experiment was also performed to investigate whether precipitation occurrred in algal cultures maintained in darkness. The carbonate site mechanistic model, developed for calcite precipitation in abiotic conditions, was used to analyse the results of the algal experiments and found to be applicable. 相似文献
9.
J. P. Sherry B. F. Scott E. Nagy B. J. Dutka 《Journal of Aquatic Ecosystem Stress and Recovery (Formerly Journal of Aquatic Ecosystem Health)》1994,3(2):129-137
In Canada, environmental regulations for protection of the biota from the adverse effects of effluents from petroleum refineries have tended to focus on acute toxicity. There is concern those effluents may have other subtle, but still deleterious, long-term effects on aquatic ecosystems. We have used a battery of toxicity tests to assess the acute toxicity, genotoxicity, and chronic toxicity of effluent samples from two Ontario refineries. The test organisms included representatives of the bacterial, algal, plant, cladoceran, and fish communities. The results of our preliminary study indicate that the effluent samples had little acute toxicity to the test organisms. There were indications of some sublethal toxicity to Ceriodaphnia dubia, Panagrellus redivivus, and Pimephales promelas. One of the effluents inhibited the growth of Selanastrum capricornutum (IC50 of 59.9%) and Lemna gibba (IC25 of 73.3%) and also caused a 15 percent reduction in the germination of Lactuca sativa seeds. The SOS-Chromotest, a commercially available test that measures the activity of a bacterial DNA repair system, detected genotoxic effects in a single effluent that had been concentrated ten fold. There was no apparent relationship between several chemical parameters and the observed sublethal effects. Further research is needed to establish whether or not the observed toxic effects are typical of effluents from Ontario refineries. 相似文献
10.
Seven small artificial lakes in West Virginia were sampled in the spring and fall. Water taken during these isothermal periods was used for the EPA Algal Assay with Selenastrum capricornutum as the test alga. In all cases the limiting nutrient was phosphorus. However in every case the water was fertile enough for the alga to grow well without the addition of nutrients. Each lake was sampled several times during the summer and nutrient analysis and chlorophyll concentrations indicated that each lake is probably eutrophic. These conclusions were borne out by the algal assays. The assays also indicated that there were probably no toxic elements in any of the seven lakes. 相似文献
11.
Since the massive bloom in 1988 in the North Sea, the prymnesiophyte flagellate Chrysochromulina polylepis Manton et Parke has been known for its ichtyotoxicity. Laboratory experiments using two different clones of C. polylepis were conducted in a comparative approach. Both clones were nearly similar in size and shape, but differed in their toxicity, as demonstrated by the Artemia bioassay. In order to study the effects of toxic C. polylepis on protozooplankton grazers, grazing experiments were performed with the heterotrophic dinoflagellate Oxyrrhis marina Dujardin as grazer. A first experiment was carried out in order to follow batch culture growth and initial grazing of O. marina when fed toxic or non-toxic clones of C. polylepis. Ingestion of the toxic clone was 27% of ingestion when fed with the non-toxic clone. When O. marina was fed with the toxic clone, vacuoles within O. marina contained fewer food particles per cell and the cells attained slower division rate (58% of the division rate estimated for the non-toxic clone). A second experiment was conducted to determine the grazing and growth response of O. marina as a function of algal food concentration. Profound differences in ingestion, clearance, division and gross growth efficiency of O. marina when fed the two clones of C. polylepis again were apparent. However, even at algal concentrations of 400×103 ml−1, O. marina is not killed by the presence or by the ingestion of toxic C. polylepis, indicating that the toxin deters grazers. In addition to grazing experiments, lipid classes and fatty acids of both algal clones were analysed and compared in order to follow the hypothesis that toxicity of C. polylepis is caused by liposaccharides, lipids, or fatty acids. However, the chemical composition with respect to lipid classes and fatty acids of both clones were quite similar, making an involvement of these substances in the toxicity towards Artemia and O. marina unlikely. 相似文献
12.
Summary
p-Nitrophenol (PNP),m-nitrophenol (MNP), 2,4-dinitrophenol (DNP) and catechol were tested for their effects on algal population in a soil and on
pure cultures of two algae isolated from soil. Both PNP and MNP, even at 0.5 kg ha−1 level were toxic to the soil algae; high doses effected increase in toxicity. Inhibition of algae was relatively more with
PNP compared to the other two nitrophenols. Catechol treatment up to 1.0 kg ha−1 led to a significant initial enhancement of algae with a subsequent far less toxic effect.
The toxicity of the phenolic compounds towardChlorella vulgaris, a green alga andNostoc linckia, a blue-green alga, decreased in the order: MNP≧PNP>DNP>Catechol. However, algicidal or algistatic effect of the test chemicals
was fairly more againstC. vulgaris, suggesting that the eukaryotic alga is highly sensitive to such soil pollutants compared to the prokaryotic alga. 相似文献
13.
Equations relating productivity, growth rate, cell concentration, and light absorption lead to the prediction that, when incident light is below saturating intensity, maximal productivity will occur at half the maximal growth rate. The freshwater alga Chlorella pyrenoidosa TX71105 and the marine alga Dunaliella tertiolecta were grown in a small continuous culture apparatus with turbidostatic control. With both cultures, the cell concentration showed a linear decrease with dilution rate. Productivity was maximal at about one-half the maximal dilution rate. Average mass per cell increased near the maximal dilution rate, causing some asymmetry in the productivity versus dilution rate curve. The chlorophyll content per unit mass decreased in this region, but the chlorophyll content per cell remained constant. Best production rate in a light-limited algal culture was obtained when the growth rate at very low cell concentration was determined in the apparatus and the dilution rate was set at one-half that value. 相似文献
14.
We examined reproductive responses of the cladoceran Daphnia parvula to algal assemblages from the Potomac River, during and after Cyanobacterial blooms. Algal assemblages were manipulated by filtration, dilution, or additions of nutritious algae, in order to determine causes for growth inhibition. There was no evidence for lethal toxic effects or food limitation of population growth rates during the algal bloom, although growth was food limited later in the year. However, growth rates were lower in the experiment conducted during the Cyanobacteria bloom than in later experiments, and the results suggest an inhibitory factor associated with the particulate material. Results from filtered treatments indicate that picoplankton present in hypereutrophic waters can support Daphnia growth and reproduction. 相似文献
15.
Claudia Fileto Marlene S. Arcifa Juliana M. Marchetti Izabel C. Turati Norberto P. Lopes 《Aquatic Ecology》2007,41(4):557-568
Five laboratory experiments were performed to evaluate the effect of supplements of fatty acids and a green alga on the individual
growth and reproduction of three species of tropical cladocerans Ceriodaphnia richardi, Daphnia ambigua, and D. gessneri feeding on natural seston from the Brazilian Lake Monte Alegre. Cohorts of newborns from cultivated females were submitted
to one of the following treatments: (1) Natural seston, (2) Natural seston + microcapsules of EPA and DHA or linoleic and
linolenic fatty acids, (3) Natural seston + oil-free microcapsules, and (4) Natural seston + green alga Scenedesmus spinosus (1 mg C l−1). Particulate organic carbon, algal carbon, C:P ratios of seston and green alga, polyunsaturated fatty acids (PUFA) content
of seston and cladocerans, as well as phytoplankton composition, size, and shape were measured. The addition of fatty acids
to seston did not significantly enhance growth and reproduction of the cladocerans, suggesting that sestonic PUFA content
is sufficient for promoting cladoceran development, even in the cool–dry season when the fatty acids used in the experiments
were 5–10 times lower in the seston than in the warm–wet season. Despite high C:P molar ratios in most experiments, there
was only one indication of growth limitation by P. Reproduction was more affected than individual growth on some occasions
by food quantity (energy) caused apparently by algal size, morphology, and digestion resistance. Energy availability, which
is affected by algae morphological characteristics, seems to prevail over PUFA and P in controlling growth and reproduction
of cladocerans in tropical Lake Monte Alegre. 相似文献
16.
Multiple addition bioassay of Tjeukemeer water 总被引:6,自引:6,他引:0
Multiple addition bioassay of water from the eutrophic lake Tjeukemeer revealed that in 1979 from the end of May until the end of November, when the lake was dominated by Oscillatoria agardhii, N and not P was the principal factor limiting algal growth. During periods with very low concentrations of Tot-Fediss in the lake, chelated Fe also limited algal growth in the bioassays. The results of this study further suggested that the concentrations of trace metals have reached levels toxic to phytoplankton. Trace metals inhibited growth particularly when the lake received relatively humus-poor IJsselmeer water with a lower metal binding capacity. 相似文献
17.
Screening of algal strains for metal removal capabilities 总被引:1,自引:0,他引:1
JoAnn C. Radway Edward W. Wilde Michael J. Whitaker Joseph C. Weissman 《Journal of applied phycology》2001,13(5):451-455
Eight algal species were tested for their ability to remove five toxic metalsduring 30-min exposures to single-metal (1 mg L-1) solutions at pH7. Efficacy of metal bioremoval varied according to algal species and metal. Al+3 was best removed by the thermophilic blue-green alga(cyanobacterium) Mastigocladus laminosus, Hg+2 and Zn+2 by the thermophilic and acidophilic red alga Cyanidiumcaldarium, and Cd+2 by C. caldarium and the green alga Scenedesmus quadricauda. All of these alga/metal combinations resultedin >90% metal removal. However, none of the eight algal speciesremoved more than 10% of Cr+6. Results indicate that some toxicmetals are more readily removed than others are by algae and that selectionof appropriate strains could potentially enhance bioremoval of specificmetals from wastewater at neutral pH. 相似文献
18.
Model experiments on a possibility that pathogenic enterobacteria Salmonella enteritidis (Gartneri) can grow on decaying algal mats with prevalence of the filamentous algae Cladophora glomerata (L.) Kütz were carried out. Samples of algal mats have been collected in the eastern part of the Gulf of Finland in the Baltic
Sea. A bacterial culture of Salmonella enteritidis was placed into tubes containing samples of mats. The intensive growth of salmonella was noted in alga samples collected
in the freshwater zone (salinity 0.2–1.5‰); growth was practically absent in the samples of algae collected in a zone with
salinity 2–3‰, while salmonella remained viable in the control tubes with water without algae. The growth of coliform enterobacteria
initially inhabited in the algal mats was discovered in all experiments. Studies carried out in 2009 show that the thickness
of the algal mats in the costal zones of the Gulf of Finland reached 20 cm and their biomass reached a few tons per 1 km2. These experiments showed that dead algal mats stimulate the growth of enterobacteria in the littoral zone of the Baltic
Sea, especially in the freshwater part, and can promote the development of these pathogenic microorganisms. 相似文献
19.
J. C. Priscu R. P. Axler R. G. Carlton J. E. Reuter P. A. Arneson C. R. Goldman 《Hydrobiologia》1982,96(2):113-120
The contribution of bacteria to total primary production was estimated in Big Soda Lake and related to vertical profiles of biomass and various physical and chemical properties. The purple sulfur bacteriaThiocapsa sp. was responsible for 25% of the total primary production. Bacteriochlorophyll (BChl) distribution and DCMU sensitivity experiments confirmed this bacterial activity. High concentrations of photosynthetically inactive phytoplankton were detected in anaerobic-low redox water and were attributed to an early season algal bloom that had settled into a zone of maximal viscosity. Nutrient enrichment bioassay experiments indicated that iron was the most important nutrient controlling early season algal growth. 相似文献
20.
E. Jordaan M. P. Roux-van der Merwe J. Badenhorst G. Knothe B. M. Botha 《Journal of applied phycology》2018,30(3):1533-1547
A key reason inhibiting commercialization of algal oil as biodiesel feedstock, is cultivation cost. For this reason, the usability of 19 readily available industrial effluents (autoclaved and non-autoclaved) to support heterotrophic growth and lipid accumulation was evaluated using six mixed algal cultures. Autoclaved whey effluent was the best with 14.32 g biomass L?1, 13.23% lipids, resulting in a lipid production of 1.91 g lipids L?1. Biomass production and lipid accumulation were in many cases inverse, e.g. mixed algal culture termed TUT4 accumulating 84.25% lipids on autoclaved acid mine drainage, with very little biomass produced. Biomass production was dependent on the effluent type, whereas the lipid accumulation was influenced mostly by the specific mixed algal cultures. The fatty acid composition of the algal oil (fish cannery and whey effluents) showed high saturation, leading to acceptable cetane numbers, kinematic viscosity, good oxidative stability, but poor cold flow properties. 相似文献