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1.
ABSTRACT: As a part of a water quality survey of the Spoon River, Illinois, algal genera were identified and their densities were enumerated. Weekly samples were collected at five stations starting on June 1, 1971. This report presents the first year's results. Algal densities for each station were found to be distributed geometrically normal. Total algal densities increased as water progressed downstream. Although water temperature has been observed to be an important factor affecting the density and the composition of algae in streams, attempts to correlate algal densities with temperatures for the Spoon River were not fruitful. Correlations of algal densities with dissolved oxygen, flow, and coliform densities also could not be made. The dominant genera observed were Cyclotella, Navicula, Scenedesmus, and Euglena. On the average diatoms accounted for 87% of all algae counts. The average diversity indices varied about 1.0 to 1.5 for five stations. There did not appear to be any advantage in the use of diversity index over that of algal density and genera richness in characterizing algae in the Spoon River.  相似文献   

2.
ABSTRACT: Filtering efficiency of the fathead minnow (Pimephales promelas), gizzard shad (Dorosoma cepedianum), carp (Cyprinus carpio), and a freshwater mussel (Elliptio coinpianata) was measured in field and laboratory trials to assess the ability of each species to control phytoplankton and suspended solid densities. All fish species tested were ineffective filterers and generally increased, rather than suppressed, algal and suspended solid concentrations. Filtering efficiencies of fish varied between -354 and 84 percent, depending on the size, shape, abundance, palatability, composition, and resistance to digestion of the particles. Because of poor filtering abilities, unpredictable feeding habits, and sensitivity to stress, the fish species examined are not effective biological controls in waste lagoons. In contrast, the freshwater mussel Elliptio was a highly effective control organism, averaging 66 percent filtering efficiency over a wide size range of algal and suspended particles. Filtration efficiency was positively correlated with mussel density. Elliptio was efficient at filtering small particles, which are particularly difficult to remove. Mean filtration rates ranged from 53 to 134 ml/mussel/h depending on the algal species consumed and algal densities (range 50–180,000 cells/ml) and 3 mg/L/mussel/h on suspended solids (range 14 to 112 mg/L). Water clarification was facilitated by both direct consumption and pseudofeces deposition. Elliptio and probably other mussel species can effectively control algae and suspended solids in wastewater lagoons and eutrophic lakes, if environmental conditions, especially dissolved oxygen levels, are suitable (>5 mg/L) for their survival.  相似文献   

3.
ABSTRACT A water quality investigation on Utah Lake was conducted during the same time period that the Heat Capacity Mapping Mission (HCMM) satellite was collecting thermal infrared and reflectivity data. Relationships were established and evaluated among HCMM data and lake water quality parameters. Although remotely sensed reflective data have been previously utilized, this study was unique in that thermal emitted data were also correlated to algae concentrations and other indicators. Standard statistical evaluations were made along with utilization of color graphics techniques to identify and plot relationships. The emitted thermal energy was found to have high positive correlations with net algal concentrations and with the predominant species, Aphanizomenon flos-aquae, a blue-green alga. No continuous correlation was found for a less abundant red pigment phytoplankton, Ceratium hirundinella. Similar trends, though for negative correlations, were shown for reflectivity data and algal concentrations throughout the spring and summer. Coincidence of areas of warmer emitted energy and darker relfected energy on colorgraphics displays clearly indicate lake areas of high algal concentrations. Night thermal data displayed a strong negative correlation with algal concentration, opposite to day thermal data. Color graphics of warmer day emitted energy and cooler night emitted energy further verify areas of high algal concentrations.  相似文献   

4.
Lutz-Carrillo, Dijar J., Gregory M. Southard, and Loraine T. Fries, 2010. Global Genetic Relationships Among Isolates of Golden Alga (Prymnesium parvum). Journal of the American Water Resources Association (JAWRA) 46(1):24-32. DOI: 10.1111/j.1752-1688.2009.00388.x Abstract: Prymnesium parvum is considered among the most harmful algal species in the world for finfish and other gill breathing organisms. Although it is globally distributed, with the exception of Antarctica, P. parvum is usually associated with coastal and brackish waters. Historically, P. parvum incidents were recorded in the eastern hemisphere; however, in 1985 it was detected in inland Texas waters. We used DNA sequence variation of the first internal transcribed spacer in the nuclear ribosomal operon (ITS1) among multiple samples of P. parvum from Texas and other locales to address the possible origins of P. parvum in Texas and the United States (U.S.). With the exception of a sample from Diversion Lake, other samples from Texas, South Carolina, and Wyoming exhibited limited genetic variation and were similar in sequence to a sample from Scotland. The Diversion Lake sample was similar in sequence to samples from Denmark and Norway, and the Maine sample was highly similar to samples from England. These results suggest multiple independent introductions of P. parvum to the U.S.  相似文献   

5.
ABSTRACT: The transmission of disease in ground water is a topic of great concern to government agencies, ground water specialists, and the general public. The purpose of this study was to compare the temporal variability in storm flow of fecal coliform bacteria densities and Cryptosporidium parvum oocyst densities in agriculturally impacted karst ground water. Cryptosporidium parvum oocyst densities ranged from 0 to 1,050 oocysts/1, and mean storm densities ranged from 3.5 to 156.8 oocysts/1. Fecal coliform densities ranged from less than 1 CFU/100ml to more than 40,000 CFU/100ml, and geometric mean storm densities ranged from 1.7 CFU/100ml to more than 7,000 CFU/100ml. Fecal coliform densities correlated well with flow during storms, but Cryptosporidium oocyst densities exhibited a great deal of sample to sample variability and were not correlated with flow. Fecal coliform densities did not correlate positively with Cryptosporidium oocyst densities. Fecal coliform densities were greatest at storm peaks, when sediment loads were also greatest. Multiple transport mechanisms for fecal coliform bacteria and C. parvum oocysts may necessitate various agricultural land management and livestock health maintenance practices to control movement of pathogens to karst ground water.  相似文献   

6.
Abstract: Nutrient dose‐response bioassays were conducted using water from three sites along the North Bosque River. These bioassays provided support data for refinement of the Soil and Water Assessment Tool (SWAT) model used in the development of two phosphorus TMDLs for the North Bosque River. Test organisms were native phytoplanktonic algae and stock cultured Pseudokirchneriella subcapitata (Korshikov) Hindak. Growth was measured daily by in vivo fluorescence. Algal growth parameters for maximum growth (μmax) and half‐saturation constants for nitrogen (KN) or phosphorus (KP) were determined by fitting maximum growth rates associated with each dose level to a Monod growth rate function. Growth parameters of native algae were compared between locations and to growth parameters of P. subcapitata and literature values. No significant differences in half‐saturation constants were indicated within nutrient treatment for site or algal type. Geometric mean KN was 32 μg/l and for KP 7 μg/l. A significant difference was detected in maximum growth rates between algae types but not between sites or nutrient treatments. Mean μmax was 1.5/day for native algae and 1.2/day for stock algae. These results indicate that watershed‐specific maximum growth rates may need to be considered when modeling algal growth dynamics with regard to nutrients.  相似文献   

7.
ABSTRACT Changes in water chemistry, water clarity, and planktonic chlorophyll a were measured as hydrilla (Hydrilla verticillata) abundance increased and then decreased in Lake Baldwin, Florida. Grass carp (Ctenopharyngodon idella) were used to eliminate submersed macrophytes. No major trends in lake pH, conductivity, or total nitrogen concentrations occurred in association with changes in hydrilla levels. Increased Secchi disc transparency and reductions in total alkalinity, calcium, magnesium, potassium, total phosphorus, and chlorophyll a concentrations occurred as hydrilla abundance increased. Large increases in the chemical parameters and a reduction in Secchi disc transparency occurred as hydrilla decreased and was eliminated from the lake by grass carp. The effects of hydrilla on lake water chemistry are related to the percentage of the lake's volume infested with hydrilla and macrophyte standing crop.  相似文献   

8.
In lakes which experience water quality problems due to the nuisance growth of blue-green algae, summer concentrations of chlorophyll a may not always be a meaningful measure of water quality for making management decisions. Models for the prediction of summer mean blue-green algal biomass were thus developed from data collected from five systems located in North America and Sweden. It is suggested that the model of choice is log BG =?0.142 + 0.596 log TP – 0.963 log Z, where BG is the biomass of blue-green algae (g m?3), TP is the concentration of total phosphorus (mg m?3), and Z is the mean depth of the lake (m). When coupled to current loading models, this model can potentially be used to assess the impacts of phosphorus loading reductions on threshold odor in water supplies.  相似文献   

9.
ABSTRACT: The influence of sediment resuspension on the water quality of shallow lakes is well documented. However, a search of the literature reveals no deterministic mass-balance eutrophication models that explicitly include resuspension. We modified the Lake Okeechobee water quality model - which uses the Water Analysis Simulation Package (WASP) to simulate algal dynamics and phosphorus, nitrogen, and oxygen cycles - to include inorganic suspend. ed solids and algorithms that: (1) define changes in depth with changes in volume; (2) compute sediment resuspension based on bottom shear stress; (3) compute partition coefficients for ammonia and ortho-phosphorus to solids; and (4) relate light attenuation to solids concentrations. The model calibration and validation were successful with the exception of dissolved inorganic nitrogen species which did not correspond well to observed data in the validation phase. This could be attributed to an inaccurate formulation of algal nitrogen preference and/or the absence of nitrogen fixation in the model. The model correctly predicted that the lake is light-limited from resuspended solids, and algae are primarily nitrogen limited. The model simulation suggested that biological fluxes greatly exceed external loads of dissolved nutrients; and sediment-water interactions of organic nitrogen and phosphorus far exceed external loads. A sensitivity analysis demonstrated that parameters affecting resuspension, settling, sediment nutrient and solids concentrations, mineralization, algal productivity, and algal stoichiometry are factors requiring further study to improve our understanding of the Lake Okeechobee ecosystem.  相似文献   

10.
在2年内分季度调查滆湖浮游植物种群和水环境因子,分析藻密度的空间分布状况以及按时间序列的藻密度变化和浮游植物优势种群变化,分别采用"多元线性逐步回归法"和"偏相关系数法"进行藻密度驱动因子识别。结果表明,滆湖藻密度空间分布趋势为由北向南逐渐升高,年际间季节差异极显著。浮游植物的演替规律为冬、春季节以绿藻和硅藻为主,夏、秋季节蓝藻占绝对优势。通过比较2种统计方法的计算结果,确定全湖及中、南部湖区藻密度的驱动因子是温度和高锰酸盐指数,北部湖区藻密度的驱动因子是温度和硝酸盐氮,所有驱动因子对滆湖藻密度的影响均为正效应。在富营养化严重的滆湖,N,P营养盐已经不再是浮游植物生长的主要驱动因子,从统计方法的角度解释了部分环境因子没有入选为驱动因子的原因,并推断了其他可能的驱动因子。  相似文献   

11.
ABSTRACT: Dilution/flushing has been documented as an effective restoration technique to restore eutrophic Moses and Green Lakes in Washington State. The dilution water added to both lakes was low in nitrogen and phosphorus content relative to the lake or normal input water. Consequently, lake nutrient content dropped predictably. Dilution or flushing rates were about ten times normal during the spring-summer periods in Moses Lake and three times normal on an annual basis in Green Lake. Improvement in quality (nutrients, algae, and transparency) was on the order of 50 percent in Moses Lake and even greater in Green Lake. The facilities for supplying dilution water were largely in place for the cited lakes; thus, costs for water transport were minimal. Available facilities, and therefore, costs, for water transport would usually vary greatly, however. Achieving maximum benefit from the technique may be more limited by availability of low nutrient water rather than facilities costs. Quality improvement may occur from physical effects of algal cell washout and water column instability if only high nutrient water is available.  相似文献   

12.
Roelke, Daniel L., Leslie Schwierzke, Bryan W. Brooks, James P. Grover, Reagan M. Errera, Theodore W. Valenti, Jr., and James L. Pinckney, 2010. Factors Influencing Prymnesium parvum Population Dynamics During Bloom Initiation: Results from In-Lake Mesocosm Experiments. Journal of the American Water Resources Association (JAWRA) 46(1):76-91. DOI: 10.1111/j.1752-1688.2009.00392.x Abstract: The alga Prymnesium parvum forms large fish-killing blooms in many Texas lakes. In some of these lakes, however, P. parvum occurs but does not develop blooms. In this study, we investigated factors that may influence bloom initiation by conducting a series of in-lake experiments involving mixing of waters from Lake Whitney, which has a history of P. parvum blooms, with waters from Lake Waco where no blooms have occurred. In all experiments, the addition of Lake Waco waters resulted in a poorer performance of P. parvum. Various experimental treatments and field data show that differences in grazing, pathogens, nutrients, and salts between the two lakes were not likely factors that contributed to this observation. Industrial and agricultural contaminants, allelochemicals and algicidal chemicals were not measured as a part of this research. However, anthropogenic contaminants other than nutrients were not observed at levels exceeding water quality standards in Lake Waco in recent years. On the other hand, nuisance cyanobacteria are common in Lake Waco, where Microcystis sp. and Anabaena sp. were abundant during the initiation of our experiments, both taxa are known to produce chemicals with allelopathic properties. In addition, the emergent field of algal-heterotrophic bacteria interactions suggests that chemicals produced by heterotrophic bacteria should not be overlooked. Further research focusing on the chemical interactions between cyanobacteria and P. parvum, as well as the potential role of algicidal bacteria, in the initiation of P. parvum blooms is necessary, as it may be important to the management of these blooms.  相似文献   

13.
ABSTRACT: The Lower Fox River, Wisconsin, hosts the densest concentration of paper mills in the US., with 18 located along a 4Gde stretch between Lake Winnebago and Green Bay, Lake Michigan. Some of these companies use only primary, others also secondary, waste treatment techniques. Comparison of the quantities of wastes discharged with the legal limits indicates that all plants discharge only 40-50 percent or less of the allowable suspended solids; most discharge < 50 percent of the allowable BOD. This is equal or better than the performance of paper companies elsewhere in the state. Reductions in pollutant discharges have corresponded to improved water quality, though too much BOD is still discharged to be adequately assimilated by the Fox River. The relatively low current level of discharges means permit levels would have to be drastically cut to make any significant impact on water quality. Only a few companies might be seriously affected by such changes. Flow and temperature related permits would likely be more effective, but more difficult to comply with for the industry. Toxic substances are also a potential problem, particularly chlororganic compounds that can form in situ from the chlorine frequently used for pulp bleaching.  相似文献   

14.
Phenol and substituted phenols are toxic organic pollutants present in tannery waste streams. Environmental legislation defines the maximum discharge limit to be 5–50 ppm of total phenols in sewers. Thus the efforts to develop new efficient methods to remove phenolic compounds from wastewater are of primary concern. The present work aims at the use of a modified green macro alga (Caulerpa scalpelliformis) as a biosorbent for the removal of phenolic compounds from the post-tanning sectional stream. The effects of initial phenol concentration, contact time, temperature and initial pH of the solution on the biosorption potential of macro algal biomass have been investigated. Biosorption of phenol by modified green macro algae is best described by the Langmuir adsorption isotherm model. Biosorption kinetics of phenol onto modified green macro algal biomass were best described by a pseudo second order model. The maximum uptake capacity was found to be 20 mg of phenol per gram of green macro algae. A Boyd plot confirmed the external mass transfer as the slowest step involved in the biosorption process. The average effective diffusion coefficient was found to be 1.44 × 10−9 cm2/s. Thermodynamic studies confirmed the biosorption process to be exothermic.  相似文献   

15.
ABSTRACT: Twenty, 0.2 hectare ponds were utilized for a four-year evaluation of three aquatic vegetation control techniques: a combination of inorganic fertilization and mechanical harvesting, aquatic herbicides, and grass carp (Ctenopharyngodon idella). Ponds used for herbicide and grass carp treatments were managed at three levels of aquatic vegetation (none, 40 and 70 percent plant occupation). Submersed vegetation was not controlled with inorganic fertilization. Vegetation levels were maintained for less than 30 days after mechanicai harvesting. Submersed macrophytes were not completely eliminated with herbicides, but the herbicide treatments utilized were effective at maintaining aquatic vegetation above 30 percent pond volume occupation. Grass carp consumed all species of submersed vegetation at the stocking densities used in this study; therefore, planned levels of submersed macrophytes were not maintained. Grass carp did not consume all floating leaf vegetation, but after four years some grass carp ponds did have lower densities of floating leaf plants. Fertilization costs were $608/hectare/year, and mechanical harvesting costs were $1979/hectare/year, resulting in a total aquatic vegetation treatment cost of $2587/hectare/ year. Herbicide costs for the different treatment levels ranged from $417/hectare/year to $1339/hectare/year over the four-year period. Grass carp were the most economical vegetation control measure tested, with costs ranging from $159/hectare/year to $248/hectare/year for the four-year study.  相似文献   

16.
Mine-drainage treatment wetland as habitat for herptofaunal wildlife   总被引:1,自引:0,他引:1  
Land reclamation techniques that incorporate habitat features for herptofaunal wildlife have received little attention. We assessed the suitability of a wetland, constructed for the treatment of mine-water drainage, for supporting herptofaunal wildlife from 1988 through 1990 using diurnal and nocturnal surveys. Natural wetlands within the surrounding watershed were also monitored for comparison. The treatment wetland supported the greatest abundance and species richness of herptofauna among the sites surveyed. Abundance was a function of the frog density, particularly green frogs (Rana clamitans) and pickerel frogs (R. palustris), while species richness was due to the number of snake species found. The rich mix of snake species present at the treatment wetland was believed due to a combination of an abundant frog prey base and an amply supply of den sites in rock debris left behind from earlier surface-mining activities. Nocturnal surveys of breeding male frogs demonstrated highest breeding activity at the treatment wetland, particularly for spring peepers (Hyla crucifer). Whole-body assays of green frog and bullfrog (R. catesbeiana) tissues showed no differences among sites in uptake of iron, aluminum, and zinc; managanese levels in samples from the treatment wetland were significantly lower than those from natural wetlands. These results suggest that wetlands established for water quality improvement can provide habitat for reptiles and amphibians, with the species composition dependent on the construction design, the proximity to source populations, and the degree of acidity and heavy-metal concentrations in drainage waters.  相似文献   

17.
ABSTRACT Atmospheric scientists have predicted that large-scale climatic changes will result from increasing levels of tropospheric CO2 We have investigated the potential effects of climate change on the primary productivity of Castle Lake, a mountain lake in Northern California. Annual algal productivity was modeled empirically using 25 years of limnological data in order to establish predictive relationships between productivity and the climatic variables of accumulated snow depth and precipitation. The outputs of monthly temperature and precipitation from three general circulation models (GCMs) of doubled atmospheric CO2 were then used in the regression model to predict annual algal productivity. In all cases, the GCM scenarios predicted increased algal productivity for Castle Lake under cenditions of doubled atmospheric CO2The primary cause of enhanced productivity was the increased length of the growing season resulting from earlier spring ice-out.  相似文献   

18.
The population growth patterns of four cladocerans, viz. Alona rectangula, Ceriodaphnia dubia, Moina macrocopa and Daphnia pulex on wastewaters from a treatment plant at Iztacalco, Mexico City were analyzed in this study. Crude wastewater (tank A) did not support A. rectangula and all animals in the replicates died after 5 days. A. rectangula with partially treated wastewater (tank B) showed growth curves similar to controls where algal density was 1 x 10(6) cells ml(-1). With wastewater from tank C (last stage before treatment with purifying agents such as chlorine), the populations maintained a low density (7 ind. ml(-1)). In wastewaters from tanks A and B, C. dubia showed no positive population growth, but in water from tank C, they maintained a low density (2 ind. ml(-1)). D. pulex showed no positive growth in all replicates involving wastewater. Only in controls (diet of algae Chlorella), the population density increased with time. M. macrocopa showed higher population growth in crude wastewaters than controls. Partially treated wastewater from tank B also resulted in a greater population growth than in the controls. However, when wastewater from the tank C was used, the population declined after day 12. Under comparable conditions, A. rectangula reached much higher peak abundances (55 ind. ml(-1)) than the rest of the cladoceran species. The rates of population growth (r) of the tested cladoceran species followed trends similar to the peak population densities. A. rectangula had the highest growth rates (0.25 per day) in controls and from the wastewater from tank B. The r-values were negative for A. rectangula and C. dubia in crude wastewater. For M. macrocopa the r-values were higher (0.19) in crude wastewater than in algae (0.15). However, r-values of M. macrocopa became negative when cultured in treated wastewater from tank C.  相似文献   

19.
The epipellic algae of Qua Iboe Estuary was studied in late summer (between January and February) of 1999. Physicochemical analysis of the tidal mud flats of the Estuary revealed a mixohaline habitat characterized by its high acidity (pH 4.72±0.02) and rich nutritive salts content. The results of the phytoplankton studies revealed variation in the density of the microalgae within the microalgal Orders. The epipellic algae community was predominated by pinnate diatoms. The mean densities of the phytoplanktons ranged from 102.75 organism/ha, 34.25 organism/ha, 21.25 organism/ha to 1.00 organism/ha of Pennales, Centrales, Zygnematales and Blue-Green algae, respectively. Their densities, however, decreased with increase in sampling distance from the low tide level. At the species level, Actinoptychus undulatus and Tabellaria sp. predominate the microalgae community. The occurrence of the freshwater diatom, A. undulatus, in an otherwise harsh salty epipellic habitat confirms the adaptive potential of some freshwater phytoplankton to marine ecosystem. Other phytoplankter present in the epipellic habitat of the estuary were Amphora ovalis, Campylodis cibrosus, Cymbella lanceolata, Navicular radiosa, N. rhynocephala, Pleurosignma sp., Pinnularia viridis, Stephanodiscus sp., Closterium sp., Oscillatoria nigroviridis and Nodularia spumigena.  相似文献   

20.
ABSTRACT: Trophic classification of the Canadian nearshore waters of the Great Lakes is attempted using summer, surface water quality data for the early 1970's. A generalized Composite Trophic Index is developed using paired linear relationships for total phosphorus, chlorophyll a, and Secchi depth data for 66 defined nearshore regions. The chlorophyll a and total phosphorus relationship indicates that the nearshore waters contain a low chlorophyll a concentration for a given total phosphorus concentration than observed for the open waters of the Great Lakes or for smaller Canadian lakes. The most eutrophic nearshore regions occur in areas of relatively restricted circulation and/or high nutrient loadings. These include the Bay of Quinte, Toronto and Hamilton harbours, and portions of Lake We's Western Basin. Lakes Huron and Superior are generally oligotrophic, except for some embayments. Although nearshore water quality is highly variable, this apprach represents a reasonable compromise with respect to analytical complexity. The Composite Trophic Index removes biases introduced through the use of a single trophic state indicator and uniquely describes the nearshore water quality in terms generally comparable to other water bodies.  相似文献   

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