Phytoplankton Summer Standing Crop and Annual Productivity as Functions of Phosphorus Loading and Various Physical Factors

1977 ◽  
Vol 34 (12) ◽  
pp. 2255-2270 ◽  
Author(s):  
Ray T. Oglesby
Keyword(s):  
Standing Crop ◽  
Phosphorus Loading ◽  
Water Volume ◽  
Physical Factors ◽  
Mixing Processes ◽  
Overlying Water ◽  
Mean Values ◽  
Annual Productivity ◽  
Variable Function ◽  
Morphoedaphic Index

Relations of phytoplankton summer standing crop and annual productivity to morphometric properties and edaphic factors, especially phosphorus loading, have been examined for a large, diverse, globally distributed group of lakes. Standing crop was highly correlated with dissolved phosphorus loading when mixing of the water column was taken into account. A regression applicable to lakes of all depths is given as a log-log function with predictive confidence intervals for summer mean values. Boundary conditions for the exclusion of certain lakes have been roughly determined. For lakes of mean depth > 25 m areal loading accounted for 97% of the variance in summer phytoplankton standing crop. Phosphorus inputs to shallower systems were adjusted to give a simple approximation of the influence of mixing processes and the ratio of bottom area to overlying water volume. Annual primary productivity seems to be a more complex and variable function of phosphorus loading than is summer standing crop. The former correlated fairly well with the morphoedaphic index. Productivity and standing crop showed well-defined trends in relation to other variables, but point scatter was so great that more exact definition of these functions was not justified. Key words: phytoplankton, phosphorus, eutrophication, lakes, morphoedaphic index

Contrasting Diel Patterns of Vertical Migration in the Dinoflagellate Ceratium hirundinella in Relation to Phosphorus Supply in a North Temperate Reservoir

1988 ◽  
Vol 45 (6) ◽  
pp. 1093-1098 ◽  
Author(s):  
W. D. Taylor ◽  
J. W. Barko ◽  
W. F. James
Keyword(s):  
Vertical Migration ◽  
Soluble Reactive Phosphorus ◽  
Nutrient Content ◽  
Phosphorus Limitation ◽  
Phosphorus Loading ◽  
Water Volume ◽  
Mixing Processes ◽  
Diel Patterns ◽  
Ceratium Hirundinella ◽  
Reactive Phosphorus

Very different diel patterns of vertical migration in Ceratium hirundinella were observed during two midsummer periods of study in a north temperate reservoir. During the first study (29–30 July), Ceratium migrated within a 2-m-deep oxygenated zone, moving upward near to the surface during the day and downward to the oxic–anoxic interface at night. During the second study (7–8 August), Ceratium did not migrate towards the surface during the day. High photosynthetic oxygen production and mixing processes increased oxygen distribution from 2 to 3 m providing Ceratium with access to a significantly greater water volume, with a greater nutrient content. Riverine phosphorus loading during the week prior to the first study was about 10 times greater than during the week prior to the second study. Limiting cell phosphorus concentrations and no measurable soluble reactive phosphorus in the upper (0–3 m) water column suggested a relationship between phosphorus limitation and the cessation of positive phototaxis. Diel patterns of vertical migration in this species may be influenced by episodic variations in phosphorus and/or other nutrient loadings via riverine inputs as interflows to this reservoir.

scholarly journals Trophic interactions among sympatric zooplanktivorous fish species in volume change conditions in a large, shallow, tropical lake

2011 ◽  
Vol 9 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Rodrigo Moncayo-Estrada ◽  
Owen T Lind ◽  
Carlos Escalera-Gallardo
Keyword(s):  
Niche Breadth ◽  
Temporal Distribution ◽  
Niche Overlap ◽  
Species Interaction ◽  
Trophic Relationships ◽  
Water Volume ◽  
Species Flock ◽  
Small Range ◽  
Mean Values ◽  
Significant Difference

Significant reductions in the water volume of shallow lakes impose a restriction on species segregation promoting more interactions in the trophic relationships. The diets of three closely related zooplanktivorous silversides belonging to the Atherinopsidae species flock of lake Chapala , Mexico, were analyzed at two sites (Chirostoma jordani, C. labarcae, and C. consocium). Diets were described in critical shallow (August 2000) and volume recovery conditions (August 2005). Diets included mainly cladocerans (Bosmina, Ceriodaphnia, and Daphnia) and copepods (Cyclops). A significant difference in diets was detected when comparing years (MRPP analysis, A = 0.22, p < 0.0001) and sites at different years (MRPP analysis, A = 0.17, p = 0.004). According to niche breadth mean values, species were classified as specialized and intermediate feeders. In shallow conditions, the small range of niche breadth (1.72 to 3.64) and high diet overlap values (D = 0.64, L = 8.62) indicated a high potential for interspecific exploitative interaction. When the lake volume recovered, an increase in the niche breadth range (1.04 to 4.96) and low niche overlap values (D = 0.53, L = 2.32) indicated a reduction of the species interaction. The Mann-Whitney U-test supported this pattern by showing a significant difference between years for niche overlap (p = 0.006). The increased interaction during the low volume suggests alternative segregation in life-history variations and other niche dimensions such as spatial or temporal distribution.

scholarly journals Effect of ageing on technological properties of goose meat

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Tomasz Żmijewski ◽  
Janusz Fryderyk Pomianowski ◽  
Katarzyna Tkacz
Keyword(s):  
Water Absorption ◽  
Shear Force ◽  
Ageing Time ◽  
Free Water ◽  
Storage Period ◽  
Raw Material ◽  
Water Volume ◽  
Technological Properties ◽  
Hydration Properties ◽  
Mean Values

AbstractAmong the poultry species, goose meat is relatively hard and cohesive and characterised by the highest chewiness and gumminess. Therefore, it can be assumed that goose meat ageing can improve its quality(1,2).The aim of the study was to determine the effect of ageing time of goose breast muscle on selected technological properties.The study material consisted musclus pectoralis of Polish White Kołuda oat geese, slaughtered at 15–17 weeks of age, weighing 6–7 kg. After slaughter, carcasses were cooled and breast muscles were cut out, vacuum packed and stored at 4°C ± 1°C. Analyses were performed 1, 7, 14, 21 days post mortem on eight breast muscles on each of the days (n = 8).The following parameters were determined: pH, muscle surface and cross-section colour, natural drip, free water, water absorption, thermal drip and shear force. A one-factor variance analysis method with Duncan's test (P ≤ 0.05) was used to evaluate the variation of mean values.It was demonstrated that muscle pH increases with an increase in the cool storage period. This parameter considerably increased from day 14 of ageing. Muscle colour changes were observed only on its surface between day 1 and 21. The ageing period had an effect on the meat hydration properties. Natural drip volume increased with an increase in the storage period and corresponded with the free water volume. A significantly greater volume of natural drip (1.77%) and a lower volume of free water (8.98%) were observed on day 21. Water absorption significantly increased on day 7 of ageing and remained constant until the end of the ageing time. A similar relationship was found while evaluating the shear force. A rapid drop in shear force was observed, which reflected an increase in meat tenderness by almost 5N between day 1 and 7 of the experiment. Based on the results, it can be concluded that the analysed raw material featured the most favourable technological properties on day 7 of ageing and that an extension of the ageing process was unjustified.

Relationships of Fish Yield to Lake Phytoplankton Standing Crop, Production, and Morphoedaphic Factors

1977 ◽  
Vol 34 (12) ◽  
pp. 2271-2279 ◽  
Author(s):  
Ray T. Oglesby
Keyword(s):  
Primary Production ◽  
Standing Crop ◽  
Crop Production ◽  
Fishery Management ◽  
Cold Water ◽  
Phytoplankton Production ◽  
Fish Yield ◽  
Morphoedaphic Index ◽  
Intensively Managed ◽  
Predicted Values

Fish yield is related to annual primary production, summer phytoplankton standing crop, and the morphoedaphic index for lakes representing a wide variety of typologies by a series of models in the form of log-log regressions. Tentative boundary conditions are established by which lakes inappropriate to the models can be excluded. Confidence intervals for predicted values about the mean are given for the fish yield–phytoplankton standing crop regression. From this relation, potential yields for the lakes studied are reduced from a range of 10,000 to one of 25-fold. Efficiencies with which carbon is transferred from primary production to fish yield vary by 2 to 3 orders of magnitude and are highest for small, intensively managed ponds and lowest for large, deep, cold-water lakes. Models based upon fish yield as a function of phytoplankton production or standing crop are inherently more accurate and subject to fewer exceptions than are those related to morphoedaphic factors. The former appear to be capable of substantial refinement but even in their present state might be employed to make useful predictions for groups of lakes. A suggested supplement to existing approaches in fishery management involves the following sequence: (1) use of expectation-variability diagrams to obtain an overview of the problem, (2) selection of an appropriate model or models to predict yield, (3) prediction of a range of yields, and (4) implementation of regulations proved successful for other lakes in the same yield category. Key words: fish, lakes, phytoplankton, morphoedaphic index, fishery management

scholarly journals Two Approaches to Measure Trace Metals Fluxes at Sediment-Water Interface: Sediment Porewater Profile and Benthic Incubation

2020 ◽  
Vol 37 (3) ◽  
Author(s):  
Harmesa ◽  
A’an Johan Wahyudi
Keyword(s):  
Trace Metals ◽  
Biogeochemical Cycle ◽  
Physical Factors ◽  
Water Interface ◽  
Overlying Water ◽  
Main Challenge ◽  
Potential Impact ◽  
Incubation Method ◽  
Coefficient Of Diffusion

The biogeochemical cycle of trace metals is very likely affected by the global change in the ocean, especially due to the increasing of sea surface temperature and acidity. Thus, assessing biogeochemical cycle of trace metals will beneficial in elucidating the potential impact of climate change as well as ocean acidification. The assessment of the biogeochemical cycle of trace metals can be performed by measuring trace metals fluxes crossing the sediment-water interface. The main challenge in this measurement is the difficulty of measuring metal concentrations at trace levels due to either physical factors or biological factors that can affect the total flux. Sediment porewater profile and in situ benthic incubation are the two most commonly used methods for measuring trace metals fluxes from sediment to the overlying water or vice versa. The coefficient of diffusion and gradient of concentration are the two most important values in the sediment porewater profile method, while the constant volume involved in the container during the experiment is an important part of the in situ benthic incubation method. The purpose of this review is to provide an overview of both measurement methods deeply and predict the challenges faced in its implementation in Indonesia. Keywords: Benthic fluxes; Overlying water; Porewater; Sediment; Trace metals

scholarly journals Analysis of ice phenology of lakes on the Tibetan Plateau from MODIS data

2013 ◽  
Vol 7 (1) ◽  
pp. 287-301 ◽  
Author(s):  
J. Kropáček ◽  
F. Maussion ◽  
F. Chen ◽  
S. Hoerz ◽  
V. Hochschild
Keyword(s):  
Tibetan Plateau ◽  
Ice Cover ◽  
Optical Data ◽  
Water Volume ◽  
The Tibetan Plateau ◽  
Large Lakes ◽  
Local Conditions ◽  
Mean Values ◽  
Break Up ◽  
Ice Phenology

Abstract. The Tibetan Plateau includes a large system of endorheic (closed basin) lakes. Lake ice phenology, i.e. the timing of freeze-up and break-up and the duration of the ice cover may provide valuable information about climate variations in this region. The ice phenology of 59 large lakes on the Tibetan Plateau was derived from Moderate Resolution Imaging Spectroradiometer (MODIS) 8-day composite data for the period from 2001 to 2010. Ice cover duration appears to have a high variability in the studied region due to both climatic and local factors. Mean values for the duration of ice cover were calculated for three groups of lakes defined by clustering, resulting in relatively compact geographic regions. In each group several lakes showed anomalies in ice cover duration in the studied period. Possible reasons for such anomalous behaviour are discussed. Furthermore, many lakes do not freeze up completely during some seasons. This was confirmed by inspection of high resolution optical data. Mild winter seasons, large water volume and/or high salinity are the most likely explanations. Trends in the ice cover duration derived by linear regression for all the studied lakes show a high variation in space. A correlation of ice phenology variables with parameters describing climatic and local conditions showed a high thermal dependency of the ice regime. It appears that the freeze-up tends to be more thermally determined than break-up for the studied lakes.

Energy budget for a stream population of the freshwater clam, Sphaerium striatinum Lamarck (Bivalvia: Pisidiidae)

1984 ◽  
Vol 62 (12) ◽  
pp. 2410-2417 ◽  
Author(s):  
Daniel J. Hornbach ◽  
Thomas E. Wissing ◽  
Albert J. Burky
Keyword(s):  
Energy Budget ◽  
Standing Crop ◽  
Production Efficiency ◽  
Reproductive Effort ◽  
Energy Partitioning ◽  
Minimum Size ◽  
Energy Needs ◽  
Annual Productivity ◽  
Deposit Feeding ◽  
Growth And Reproduction

An annual energy budget was constructed for a stream population of Sphaerium striatinum. The annual productivity (P) was 2.79 g C∙m−2∙year−1 and the average standing crop biomass (B) was 0.58 g C∙m−2; the resulting annual P:B ratio of 4.58 is below that expected for a bivoltine animal. The low value for reproductive effort (Re:P = 16.1%) may partially be attributed to the ovoviviparous, iteroparous nature of this population. A strategy of partitioning a large proportion of production to growth (G:P = 83.9%) may insure a high probability of attaining the minimum size necessary for reproduction. Production accounts for 44% of assimilation (A) with 56% of A lost through respiration. The net production efficiency (P:A = 44%) is high and indicates that this population is efficient in partitioning energy to growth and reproduction. The population must consume (C) 10.57 g C∙m−2∙year−1 to meet its energy needs. Only 35% of this could be accounted for by filter feeding; the remainder may have come from deposit feeding. Comparisons of P, P:B, Re:P and P:A with published values for corbiculacean clams indicates that this population of S. striatinum is one of the most productive and efficient in its energy partitioning of populations studied to date.

Life in the benthic boundary layer: connections to the mid-water and sea floor

1990 ◽  
Vol 331 (1616) ◽  
pp. 15-28 ◽  
Keyword(s):  
Boundary Layer ◽  
Standing Crop ◽  
Novel Species ◽  
Benthic Boundary Layer ◽  
Benthic Species ◽  
Overlying Water ◽  
Significant Percentage ◽  
Sea Floor ◽  
Sea Bed ◽  
And Diffusion

The abyssal benthopelagic zone is enriched in biomass and numbers of species, relative to the overlying water column. It is inhabited by (i) pelagic species whose ranges are truncated by the sea bed, (ii) normally benthic species who use the zone as a refuge, for dispersal or for locating their food, (iii) a specialized fauna, which includes many novel species with primitive characteristics. The increase in the standing-crop in the zone is related to the greater availability of organic material on the sea bed, and the extent of its resuspension and diffusion from off the bottom. Several species are known to be capable of responding to both predictable and erratic pulses of input, but otherwise their physiologies seem to differ little from other pelagic and benthic species. These communities contribute a small but significant percentage of the benthic recycling.

scholarly journals Zonal asymmetries in middle atmospheric ozone and water vapour derived from Odin satellite data 2001–2010

2011 ◽  
Vol 11 (18) ◽  
pp. 9865-9885 ◽  
Author(s):  
A. Gabriel ◽  
H. Körnich ◽  
S. Lossow ◽  
D. H. W. Peters ◽  
J. Urban ◽  
...  
Keyword(s):  
Water Vapour ◽  
Satellite Data ◽  
Stationary Wave ◽  
Atmospheric Ozone ◽  
Mixing Processes ◽  
Linear Solution ◽  
Mean Values ◽  
Double Peak Structure ◽  
The North ◽  
Wave Patterns

Abstract. Stationary wave patterns in middle atmospheric ozone (O3) and water vapour (H2O) are an important factor in the atmospheric circulation, but there is a strong gap in diagnosing and understanding their configuration and origin. Based on Odin satellite data from 2001 to 2010 we investigate the stationary wave patterns in O3 and H2O as indicated by the seasonal long-term means of the zonally asymmetric components O3* = O3-[O3] and H2O* = H2O-[H2O] ([O3], [H2O]: zonal means). At mid- and polar latitudes we find a pronounced wave one pattern in both constituents. In the Northern Hemisphere, the wave patterns increase during autumn, maintain their strength during winter and decay during spring, with maximum amplitudes of about 10–20 % of the zonal mean values. During winter, the wave one in O3* shows a maximum over the North Pacific/Aleutians and a minimum over the North Atlantic/Northern Europe and a double-peak structure with enhanced amplitude in the lower and in the upper stratosphere. The wave one in H2O* extends from the lower stratosphere to the upper mesosphere with a westward shift in phase with increasing height including a jump in phase at upper stratosphere altitudes. In the Southern Hemisphere, similar wave patterns occur mainly during southern spring. By comparing the observed wave patterns in O3* and H2O* with a linear solution of a steady-state transport equation for a zonally asymmetric tracer component we find that these wave patterns are primarily due to zonally asymmetric transport by geostrophically balanced winds, which are derived from observed temperature profiles. In addition temperature-dependent photochemistry contributes substantially to the spatial structure of the wave pattern in O3* . Further influences, e.g., zonal asymmetries in eddy mixing processes, are discussed.

scholarly journals Diversity and structure of microcrustacean assemblages (Cladocera and Copepoda) and limnological variability in perennial and intermittent pools in a semi-arid region, Bahia, Brazil

2011 ◽  
Vol 101 (4) ◽  
pp. 317-324 ◽  
Author(s):  
Nadson R. Simões ◽  
Sylvia M. M. S. Ribeiro ◽  
Sérgio L. Sonoda
Keyword(s):  
Electrical Conductivity ◽  
Arid Region ◽  
Suspended Solids ◽  
Diversity Index ◽  
Total Alkalinity ◽  
Water Volume ◽  
Aquatic Environments ◽  
Physical Factors ◽  
Semi Arid Region ◽  
Semi Arid

Temporary wetlands undergo recurrent drought due to the scarcity of water, which disrupts the hydrological connectivity with adjacent aquatic systems. However, some environments retain water for longer periods, allowing greater persistence of the community. The current study evaluated differences in the microcrustacean assemblages and limnological variability between perennial and intermittent pools in a semi-arid region of Brazil. The abiotic features (water temperature, pH, total alkalinity, electrical conductivity and depth) of intermittent pools were affected more than perennial pools due to loss of water volume. This may have contributed to a higher average richness and diversity index in some intermittent pools and differences in the structure of the assemblages. The lowest species richness and diversity were recorded where physical factors, such as a large quantity of suspended solids and variability in the electrical conductivity of the water and pH, make the environment unsuitable for these organisms. These results suggest that community development in intermittent pools is interrupted by the dry season; when the water returns, due to rainfall or rising groundwater, each pond undergoes a different process of colonization. In these circumstances, the biological importance of temporary aquatic environments is clear, since such pools provide shelters and have an important role in the maintenance of the regional diversity of aquatic environments.

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