Influence of Reservoir Transit on Riverine Algal Transport and Abundance

1984 ◽  
Vol 41 (12) ◽  
pp. 1803-1813 ◽  
Author(s):  
D. M. Søballe ◽  
R. W. Bachmann
Keyword(s):  
Water Temperature ◽  
Retention Time ◽  
Standing Crop ◽  
Algal Biomass ◽  
Chlorophyll Concentration ◽  
Light Limitation ◽  
Des Moines ◽  
Flow Dependence ◽  
Major Loss ◽  
Chlorophyll Concentrations

The Des Moines River lost 65–75% of its algal standing crop (chlorophyll a) in passing through each of two impoundments (mean retention times 11 and 16 d), and chlorophyll concentrations within both impoundments were 50–90% below the predictions of empirical chlorophyll–nutrient models. Sedimentation of river-borne algae and light limitation within the impoundments were identified as major loss processes. A reduction in algal size from upstream to downstream in one reservoir paralleled the loss of algal biomass. Algal losses in each impoundment increased with both increasing retention time and water temperature so that chlorophyll concentration below the dams was uncoupled from the temperature and flow dependence seen in river reaches not influenced by impoundments. The reduction in riverine algal transport associated with reservoir transit was cumulative over the two-reservoir series; this reduction can be interpreted as a "reset" to river headwater conditions.

Light, Nutrients, and Water Temperature as Determinants of Phytoplankton Production in Two Saline, Prairie Lakes with High Sulphate Concentrations

1992 ◽  
Vol 49 (11) ◽  
pp. 2281-2290 ◽  
Author(s):  
Richard D. Robarts ◽  
Marlene S. Evans ◽  
Michael T. Arts
Keyword(s):  
Water Temperature ◽  
Photosynthetic Capacity ◽  
Chlorophyll Concentration ◽  
Euphotic Zone ◽  
Dominant Factor ◽  
Phytoplankton Production ◽  
Dissolved Phosphorus ◽  
Prairie Lakes ◽  
The Mean ◽  
Algal Productivity

Our data support empirical models indicating that algal productivity is low relative to total phosphorus (TP) levels in prairie lakes with high sulphate concentrations. Mean chlorophyll accounted for 91.1% of the variance in euphotic zone primary production (ΣA) in Humboldt Lake (total dissolved solids (TDS) = 3.3 g∙L−1; Zmax = 6 m), while TP, total dissolved phosphorus, and water temperature accounted for 82.7% of ΣA variance in Redberry Lake (TDS = 20.9 g∙L−1; Zmax = 17 m). The relative importance of these variables to ΣA resulted from biological, chemical, and physical differences of these lakes. Light usually penetrated to the bottom of Redberry Lake due to a mean euphotic zone (Zeu) chlorophyll of 1.7 mg∙m−3, while Humboldt Lake's mean Zeu was 3.4 m with a mean chlorophyll concentration of 62.6 mg∙m−3. Chlorophyll was the dominant factor correlated with light penetration in Humboldt Lake (r2 = 0.65) but not in Redberry Lake. Photosynthetic capacity was correlated (r2 = 0.72) with water temperature only in Redberry Lake. The mean ΣA was 57.1 and 230.2 mg C∙m−2∙h−1 for Redberry and Humboldt lakes, respectively.

scholarly journals Its What’s on the Inside That Counts: An Effective, Efficient, and Streamlined Method for Quantification of Octocoral Symbiodiniaceae and Chlorophyll

2021 ◽  
Vol 8 ◽  
Author(s):  
Rosemary Kate Steinberg ◽  
Emma L. Johnston ◽  
Teresa Bednarek ◽  
Katherine A. Dafforn ◽  
Tracy D. Ainsworth
Keyword(s):  
Protein Content ◽  
Surface Area ◽  
Water Movement ◽  
Chlorophyll Concentration ◽  
Dry Weight ◽  
Accurate Method ◽  
Host Protein ◽  
Biomass Composition ◽  
Wet Weight ◽  
Chlorophyll Concentrations

Ocean warming driven bleaching is one of the greatest threats to zooxanthellate cnidarians in the Anthropocene. Bleaching is the loss of Symbiodiniaceae, chlorophyll, or both from zooxanthellate animals. To quantify bleaching and recovery, standardised methods for quantification of Symbiodiniaceae and chlorophyll concentrations have been developed for reef-building scleractinian corals, but no such standard method has been developed for octocorals. For stony corals, quantification of Symbiodiniaceae and chlorophyll concentrations often relies on normalisation to skeletal surface area or unit of biomass [i.e., protein, ash-free dry weight (AFDW)]. Stiff octocorals do not change their volume, as such studies have used volume and surface area to standardise densities, but soft-bodied octocorals can alter their size using water movement within the animal; therefore, Symbiodiniaceae and chlorophyll cannot accurately be measured per unit of surface area and are instead measured in units of Symbiodiniaceae and chlorophyll per μg of host protein or AFDW. Though AFDW is more representative of the full biomass composition than host protein, AFDW is more time and resource intensive. Here, we provide a streamlined methodology to quantify Symbiodiniaceae density, chlorophyll concentration, and protein content in soft-bodied octocorals. This technique uses minimal equipment, does not require freeze-drying or burning samples to obtain ash weight, and is effective for down to 0.2 g wet tissue. Bulk samples can be centrifuged, the Symbiodiniaceae pellet washed, and the supernatant saved for protein analysis. This efficient technique allows for clean, easy to count samples of Symbiodiniaceae with minimal animal protein contamination. Chlorophyll a and c2 extractions occurs at different rates, with chlorophyll a taking 24 h to extract completely at 4°C and chlorophyll c2 taking 48 h. Finally, we found that where necessary, wet weight may be used as a proxy for protein content, but the correlation of protein and wet weight varies by species and protein should be used when possible. Overall, we have created a rapid and accurate method for quantification of bleaching markers in octocorals.

scholarly journals Temporal Effects of Groundwater on Physical and Biotic Components of a Karst Stream

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1299 ◽  
Author(s):  
Tao Tang ◽  
Shuhan Guo ◽  
Lu Tan ◽  
Tao Li ◽  
Ryan M. Burrows ◽  
...  
Keyword(s):  
Water Temperature ◽  
Algal Biomass ◽  
Groundwater Discharge ◽  
Stream Network ◽  
Lotic Ecosystems ◽  
Chl A ◽  
Discharge Water ◽  
Downstream Reach ◽  
Insight Into

Although most lotic ecosystems are groundwater dependent, our knowledge on the relatively long-term ecological effects of groundwater discharge on downstream reaches remains limited. We surveyed four connected reaches of a Chinese karst stream network for 72 consecutive months, with one reach, named Hong Shi Zi (HSZ), evidently affected by groundwater. We tested whether, compared with other reaches, HSZ had (1) milder water temperature and flow regimes, and (2) weaker influences of water temperature and flow on benthic algal biomass represented by chlorophyll a (Chl. a) concentrations. We found that the maximum monthly mean water temperature in HSZ was 0.6 °C lower than of the adjacent upstream reach, and the minimum monthly mean water temperature was 1.0 °C higher than of the adjacent downstream reach. HSZ had the smallest coefficient of variation (CV) for water temperature but the largest CV for discharge. Water temperature and discharge displayed a significant 12-month periodicity in all reaches not directly groundwater influenced. Only water temperature displayed such periodicity in HSZ. Water temperature was an important predictor of temporal variation in Chl. a in all reaches, but its influence was weakest in HSZ. Our findings demonstrate that longer survey data can provide insight into groundwater–surface water interactions.

scholarly journals Temporal variation of Nitella furcata subsp. mucronata var. mucronata f. oligospira (Charophyceae) in the Ninféias pond, São Paulo State, southeast Brazil

2006 ◽  
Vol 20 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Norma Catarina Bueno ◽  
Carlos Eduardo de Mattos Bicudo
Keyword(s):  
Population Density ◽  
Temporal Variation ◽  
Water Temperature ◽  
Algal Biomass ◽  
Sao Paulo ◽  
São Paulo ◽  
Dry Period ◽  
Rainy Period ◽  
Reproductive Structures ◽  
Southeast Brazil

Temporal and spatial variation of Nitella furcata (Roxburgh ex Bruzelius) C. Agardh emend. R.D. Wood subsp. mucronata (A. Braun) R.D. Wood var. mucronata f. oligospira (A. Braun) R.D. Wood were studied at the Ninféias pond (23°38'18.9"S, 46°37'16.3"W), a tropical, shallow, mesotrophic reservoir located in the Parque Estadual das Fontes do Ipiranga Biological Reserve, Municipality of São Paulo, southeast Brazil. Water samples were collected monthly from October/1996 to October/1997 for turbidity, electric conductivity, pH, alkalinity, dissolved oxygen, nutrients, biomass, and algal phenology analysis. Spatial distribution pattern of algal biomass showed that all four sampling stations were similar among themselves during the whole study period. Regarding the temporal variation, greatest algal total biomass values (98.35-266.06 g.m-2) were measured during the rainy period whereas the smallest ones (48.86-170.56 g.m-2) were detected during the dry period. Algal population density peaked at all four sampling stations from October/1996 to April/1997 (rainy period) when the greatest values of air and water temperature, precipitation, solar radiation, turbidity, total nitrogen, and ammonium were measured allowing favorable conditions for the algal growth. Period from May/1997 (late fall) to October/1997 (early spring) was favorable to the development of reproductive structures (nucules and globules) with consequent decrease of algal biomass and population density, clearly suggesting the greatest energy allocation towards the development of sexual reproductive structures. This fact was confirmed by the canonic correspondence analysis that indicated strong correlation between nucules length and width, number of nucules per plant, and oospores length and width with the low values of pH and high ones of dissolved inorganic matter detected during the dry period. Consequently, environmental factors such as increasing of water temperature and nutrients availability at the Ninféias pond acted decisively towards growth and accumulation of algal biomass.

scholarly journals Inherent Limitations of Nondestructive Chlorophyll Meters: A Comparison of Two Types of Meters

HortScience ◽  
1992 ◽  
Vol 27 (1) ◽  
pp. 69-71 ◽  
Author(s):  
Oscar A. Monje ◽  
Bruce Bugbee
Keyword(s):  
Light Scattering ◽  
Measurement Technique ◽  
Chlorophyll Concentration ◽  
Dual Wavelength ◽  
Chlorophyll Meter ◽  
Chlorophyll Concentrations

Two types of nondestructive chlorophyll meters were compared with a standard, destructive chlorophyll measurement technique. The nondestructive chlorophyll meters were 1) a custom built, single-wavelength meter, and 2) the recently introduced, dual-wavelength, chlorophyll meter from Minolta (model SPAD-502). Data from both meters were closely correlated with destructive measurements of chlorophyll (r2 = 0.90 and 0.93; respectively) for leaves with chlorophyll concentrations ranging from 100 to 600 mg·m-2, but both meters consistently overestimated chlorophyll outside this range. Although the dual-wavelength meter was slightly more accurate than the single-wavelength meter (higher r2), the light-scattering properties of leaf cells and the nonhomogeneous distribution of chlorophyll in leaves appear to limit the ability of all meters to estimate in vivo chlorophyll concentration.

The effects of elevated CO2 and canopy position on chlorophyll concentration in mature Quercus robur.

2021 ◽  
Author(s):  
Anna Gardner ◽  
David Ellsworth ◽  
Jeremy Pritchard ◽  
Rob Mackenzie
Keyword(s):  
Leaf Senescence ◽  
Photosynthetic Pigments ◽  
Quercus Robur ◽  
Dominant Species ◽  
Plant Traits ◽  
Chlorophyll Concentration ◽  
Photosynthetic Apparatus ◽  
Mature Trees ◽  
Canopy Position ◽  
Chlorophyll Concentrations

<p>The timings of phenological events play an important role in determining the annual carbon uptake in key terrestrial carbon sinks, such as mature forests. With increases in atmospheric CO<sub>2</sub> expected to change physiological processes in plants, it is becoming increasingly important to monitor the changes in plant traits and subsequent phenological changes that may occur. Changes in photosynthetic pigments, such as chlorophyll, can be used as a proxy for physiological changes in leaves and can therefore be useful to monitor potential phenological change, such as autumnal leaf senescence. Non-destructive techniques allow for measurements of photosynthetic pigments without destructive sampling that would disturb the canopy. These methods are particularly useful in logistically difficult environments, such as high forest, or remote environments where traditional chlorophyll extractions are problematic and serve as ground-truthing for remote sensing of greenness. In the present study, we aimed to assess the effects of elevated CO<sub>2</sub> (150 mmol mol<sup>-1</sup> above ambient) and canopy position on chlorophyll concentrations of a common canopy-dominant species to identify potential implications on phenology. The study was conducted in a mature temperate forest situated at a Free Air Carbon Enrichment (FACE) experiment in the UK. Over 5,000 in-situ chlorophyll measurements were collected, across the 3<sup>rd</sup> and 4<sup>th</sup> season of CO<sub>2</sub> fumigation, in the canopy-dominant species <em>Quercus robur</em> (<em>Q. robur</em>). Additionally, 100 leaves were destructively sampled to verify chlorophyll concentrations using traditional chlorophyll extraction techniques. The established relationship between chlorophyll absorptance readings and leaf chlorophyll content allowed robust species-specific calibration equations to be calculated. Consistent with previous work, this study observed significantly higher chlorophyll concentrations at lower positions in the canopy in both sampling years (P < 0.001). Additionally, a reduction in foliar chlorophyll concentrations (-2 to -9%) when exposed to eCO<sub>2 </sub>in both sampling years was observed, but this was only significant for the upper canopy (-7 to -9%, P < 0.05). This study found a marginally significant effect of CO<sub>2</sub> treatment on reducing the effective season length, with larger eCO<sub>2</sub>-induced reductions in chlorophyll occurred through autumn. Overall, the research highlights a simple non-invasive method for monitoring changes in leaf traits of mature trees under eCO<sub>2</sub>. The results suggest that leaves may be able to reallocate their resources away from light-harvesting apparatus in response to eCO<sub>2</sub>, particularly in the upper canopy. Furthermore, the findings suggest direct consequences of rising atmospheric CO<sub>2</sub> to potential alterations of phenological events, such as leaf senescence, that may have implications for forest productivity and adaptation in a future high CO<sub>2</sub> world. Additionally, the research has shown the need to monitor potential changes in resource allocation to photosynthetic apparatus across the season as atmospheric CO<sub>2</sub> continues to rise. The information obtained in this study can be used to increase accuracy in the modelling of climate-carbon scenarios.</p>

Sigmoid Relationships between Nutrients and Chlorophyll among Lakes

1989 ◽  
Vol 46 (7) ◽  
pp. 1171-1175 ◽  
Author(s):  
Edward McCauley ◽  
John A. Downing ◽  
Susan Watson
Keyword(s):  
Algal Biomass ◽  
Chlorophyll Concentration ◽  
Management Strategies ◽  
Field Research ◽  
Phosphorus Availability ◽  
Phosphorus Concentration ◽  
Data Sets ◽  
Empirical Relationships ◽  
Dissolved Phosphorus ◽  
Freshwater Eutrophication

Previous studies of freshwater eutrophication have shown that algal biomass tends to increase with the supply of dissolved phosphorus. This concept has been condensed into empirical relationships between chlorophyll a and total phosphorus concentrations (convenient measures of algal biomass and phosphorus availability) which have become essential tools in theoretical and applied limnology. With few exceptions, ecologists accept the idea that chlorophyll concentration rises linearly with phosphorus concentration among lakes. Such a suggestion runs counter to Liebigian principles of fertilization however, and contradicts laboratory and field research indicating the influence of other nutrients. Our analysis of two large independent phosphorus–chlorophyll data sets from temperate-zone lakes shows that log phosphorus–log chlorophyll relationships are sigmoid in shape and that a second nutrient, nitrogen, has a significant impact on chlorophyll concentrations when phosphorus availability is high. Our new empirical relationships indicate that mechanisms regulating algal biomass change with enrichment, and suggest new management strategies for polluted lakes.

The spatial distribution of microalgae on Antarctic fellfield soils

1991 ◽  
Vol 3 (3) ◽  
pp. 257-263 ◽  
Author(s):  
M.C. Davey ◽  
K.J. Clarke
Keyword(s):  
Algal Biomass ◽  
Degradation Products ◽  
Soil Surface ◽  
Signy Island ◽  
Excess Water ◽  
Vertical Distributions ◽  
Cyanobacteria And Algae ◽  
Horizontal And Vertical Distributions ◽  
Desiccation Avoidance ◽  
Chlorophyll Concentrations

The horizontal and vertical distributions of cyanobacteria and algae on soil polygons on Signy Island were investigated. Soil chlorophyll concentrations increased from the centre to the edge of the polygons. Similar distributions of the non-motile genera, such as Pseudanabaena and Nostoc, were observed, whereas the motile taxa, Phormidium and Pinnularia, were evenly distributed across the polygon. Phormidium autumnale was the most widespread taxon, and other Oscillatoriaceae were also important, although large differences in community composition between polygons were observed. Most of the algal biomass was concentrated near the surface of the soil, although chlorophyll degradation products were found to depths of up to 8 cm. Examination of the soil profile by fluorescence microscopy indicated that a large proportion of the microflora occurred in the zone 0–1 mm below the surface, and scanning electron microscopy confirmed that few algae occurred on the soil surface. It is suggested that this may be a desiccation-avoidance strategy. Vertical migration of the motile microalgae to the soil surface was not observed in the field, but could be induced in the laboratory in the presence of excess water, although no diel cycle to this movement was observed.

Domestic Sewage Treatment Using an Anaerobic Biofilter with an Aerobic Biofilter

1986 ◽  
Vol 18 (7-8) ◽  
pp. 209-216 ◽  
Author(s):  
Y. Inamori ◽  
R. Sudo ◽  
T. Goda
Keyword(s):  
Water Temperature ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Sewage Treatment ◽  
Domestic Sewage ◽  
Circulation Ratio ◽  
Low Strength ◽  
Bod Removal ◽  
Organic Wastewater

The purpose of this study was to assess the applicability of the anaerobic biofilter process to treat low strength organic wastewater such as domestic sewage. It was found that when the influent BOD was approximately 200 mg/l, water temperature and BOD loading, under a hydraulic retention time (HRT) of 30 hrs, were 20°C and 0.2 kg/m3.day respectively, a BOD removal of at least 70% was attained, and the ratio of sludge produced to BOD removed in the anaerobic biofilter was as low as 0.1. Furthermore it was also found that 75% of nitrogen (N) could be removed in the anaerobic-aerobic biofilter process when the circulation ratio was more than 1:2.

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