scholarly journals The trophic status of Bidighinzu Reservoir (Sardinia) before and after the diversion of waste waters

2018 ◽  
Vol 60 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Antonella LUGLIÈ ◽  
Yelda AKTAN ◽  
Paola CASIDDU ◽  
Nicola SECHI
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic Status ◽  
Water Reservoir ◽  
Early Years ◽  
Trophic Conditions ◽  
Mean Values ◽  
Annual Cycles ◽  
Drinking Water Reservoir ◽  
Before And After

The purpose of this paper was to assess the effect of the diversion of wastewater on the trophic status of Lake Bidighinzu, a hypertrophic man-made lake in Northern Sardinia, used as a drinking water reservoir. There have been problems with potabilization since the early years of the diversion operation, particularly in the summer-autumn period. Data available (August 1978, February 1979 and March 1985) before the reservoir (1987) were compared with those collected during a study carried out in the annual cycle immediately after (1988-1989) and after some years (1994 and 1996-1997). The study examined the dynamics of temperature, main nutrients (total phosphorus, nitrate and ammonia), chlorophyll-a and phytoplanktonic biomass. No particular variation in the water nutrient availability emerged from the comparison between these two situations - especially for total phosphorus, whose annual mean concentrations were similar in the two annual cycles (386 mg P m-3 in 1988-1989 and 305 mg P m-3 in 1996-1997). Chlorophyll-a and biomass were high during each period of study (annual mean values were 17 mg m-3and 3.7 mg l-1 in 1988-1989 and 11 mg m-3and 4.6 mg l-1 in 1996-1997). However, peaks were never higher than values recorded in August 1978 (112 mg m-3and 133 mg l-1) due to an extraordinary bloom of Ceratium hirundinella (O.F. Müller). Species composition of phytoplankton was typical of highly trophic conditions and was frequently characterised by the presence of Cyanophyceae and Bacillariophyceae. Results demonstrated that, ten years after construction of the by-pass, the lake had shown no improvement in its trophic status. This might depend on many factors, among which the most likely might be the non-use or partial use of the diversion system, which allows the sewage to continue to flow into the lake and keep its trophic status almost unchanged.

scholarly journals Fluctuations of the population of Daphnia laevis Birge 1878: a six-year study in a tropical lake

2012 ◽  
Vol 72 (3) ◽  
pp. 479-487 ◽  
Author(s):  
LPM. Brandão ◽  
T. Fajardo ◽  
E. Eskinazi-Sant'Anna ◽  
S. Brito ◽  
P. Maia-Barbosa
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic State ◽  
Trophic Status ◽  
Seasonal Pattern ◽  
Ecological Research ◽  
Total Phosphorous ◽  
Long Term Ecological Research ◽  
Physical And Chemical

The fluctuation of the population of Daphnia laevis in Lake Jacaré (Middle River Doce, Minas Gerais) was monitored monthly (at one point in the limnetic region) for six years (2002-2007) as part of the Program of Long-Term Ecological Research (LTER/UFMG). The following parameters were also monitored: water temperature, pH, electrical conductivity, dissolved oxygen, chlorophyll a, total phosphorus, phosphate, total nitrogen, nitrate, nitrite, ammonia, and densities of Chaoborus and ephippia of Daphnia laevis in the sediment. A seasonal pattern was observed in the fluctuation of D. laevis, with higher densities recorded during periods of circulation (May-August). A significant correlation was found between the density of D. laevis and temperature (r = -0.47, p = 0.0001), chlorophyll-a (r = -0.32, p = 0.016) and indicators of the lake's trophic status (total phosphorus, r = 0.32, p = 0.007 and trophic state, r = 0.36, p = 0.003), as well as Chaoborus density (r = 0.43 and p = 0.002). These results indicate that changes in the physical and chemical characteristics of the water related with stratification and circulation of the lake may have a direct (temperature, total phosphorous) or an indirect (food availability, presence of predators, ephippia eclosion) influence on the fluctuation of the D. laevis population.

scholarly journals Trophic Status and Phytoplankton Limitation Conditions in a Few Bulgarian and Hungarian Danube River Wetlands

2016 ◽  
Vol 18 (2) ◽  
pp. 19-28
Author(s):  
Roumen Kalchev ◽  
Árpád Berczik ◽  
Michaela Beshkova ◽  
Mária Dinka ◽  
Hristina Kalcheva ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Trophic State ◽  
Trophic Status ◽  
Danube River ◽  
Trophic State Index ◽  
Secchi Disk ◽  
State Index

Abstract The phytoplankton limitation conditions in a few Bulgarian and Hungarian wetlands and in two more sampling sites, one for each Danube stretch, were investigated by means of trophic state index of Carlson (1977) for phytoplankton chlorophyll-a (CHL), Secchi disk depths (SD), total phosphorus (TP), and total nitrogen (TN) concentrations. Phytoplankton of both river sites was not limited by non-algal turbidity, nor was they phosphorus and nitrogen limited. In summer months the studied wetlands were predominantly nitrogen limited, while in spring and autumn limitation by non-algal turbidity prevailed.

Long-Term Nutrient Loading and Biological Response in a Flood-Water Reservoir (Neue Donau) in Vienna, Austria

1993 ◽  
Vol 28 (6) ◽  
pp. 55-63 ◽  
Author(s):  
M. T. Dokulil
Keyword(s):  
Total Phosphorus ◽  
Nutrient Loading ◽  
Time Lag ◽  
Water Reservoir ◽  
Biological Response ◽  
Hydrological Regime ◽  
Nutrient Concentrations ◽  
Trophic Conditions ◽  
River Danube

Nutrient input and trophic conditions in an artificial flood protection reservoir along the river Danube in Vienna are evaluated from a 10-year data base. Nutrient concentrations were largely governed by concentrations in the River Danube (total phosphorus, P-tot = 236±41 µg/l; total nitrogen, N-tot = 2.53±0.78 mg/l), because the major input was groundwater percolating from the river through the separating island to “Neue Donau”. Concentrations were reduced by about 40% during subsurface transport (time lag approx. one day), because the sediments were mainly composed of gravel (correlation coefficient r = 0.77 for P-tot of the river vs. Neue Donau). The amount of water strongly depended on the complex hydrological regime. The decreasing concentration gradients that developed downstream in the Neue Donau are analysed in detail for the year 1991, for total phosphorus, chlorophyll-a, and phytoplankton biomass. Long-term changes of these parameters are discussed for the years 1981 to 1991. Average phosphorus concentrations for the summer period (June - September) increased from >100 µg/l in 1981 to >400 µg/l in 1984. Average chlorophyll concentrations ranged from 40 to 80 µg/l during this period, peaking in the year 1985. Both variables declined drastically in the years 1986 and 1987 and more slowly decreased thereafter. Lowest values of 40 and 10 µg/l respectively were reached in 1990 which were not significantly different from both 1989 and 1991.

Use of Lake Fossil Diatom Assemblages to Determine Historical Changes in Trophic Status

1989 ◽  
Vol 46 (6) ◽  
pp. 1013-1021 ◽  
Author(s):  
M. Agbeti ◽  
M. Dickman
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic Status ◽  
Eutrophic Lake ◽  
Regression Analyses ◽  
Diatom Assemblages ◽  
Trophic Index ◽  
Trophic Changes ◽  
Classification Index ◽  
Oligotrophic Condition

Based on the composition of surface sediment diatom assemblages of 30 lakes a classification index for lake trophic status was developed. The lakes were selected to represent a continuum ranging from oligotrophic to eutrophic lake types. A trophic index quotient was derived. The log diatom inferred trophic index (D.I.T.I.) was regressed against the trophic status of the lakes as determined by the log total phosphorus (r = 0.84) and log chlorophyll-a (r = 0.91). Multiple regression analyses showed significant correlations between log D.I.T.I. and the log percentage abundances of oligotrophic, mesotrophic, and eutrophic species (r = 0.89). The abundance of the trophic indicator diatom species depends not only on total phosphorus and chlorophyll-a, but possibly on the interaction of these with other factors. Using this approach, past trophic changes were inferred for oligotrophic Barbara Lake and eutrophic Chemung Lake. The study suggested that Barbara Lake had retained its present day oligotrophic condition over the last 200 yr, whereas major trophic changes have occurred in Chemung Lake.

A Simple Method for Predicting the Capacity of a Lake for Development Based on Lake Trophic Status

1975 ◽  
Vol 32 (9) ◽  
pp. 1519-1531 ◽  
Author(s):  
P. J. Dillon ◽  
F. H. Rigler
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Water Budget ◽  
Trophic Status ◽  
Phosphorus Concentration ◽  
Phosphorus Load ◽  
Secchi Disc ◽  
Total Phosphorus Concentration ◽  
Lake Trophic Status

A general technique is presented for calculating the capacity of a lake for development based on quantifiable relationships between nutrient inputs and water quality parameters reflecting lake trophic status. Use of the technique for southern Ontario lakes is described. From the land use and geological formations prevalent in a lake’s drainage basin, the phosphorus exported to the lake in runoff water can be calculated, which, when combined with the input directly to the lake’s surface in precipitation and dry fallout, gives a measure of the natural total phosphorus load. From the population around the lake, the maximum artificial phosphorus load to the lake can be calculated and, if necessary, modified according to sewage disposal facilities used. The sum of the natural and artificial loads can be combined with a measure of the lake’s morphometry expressed as the mean depth, the lake’s water budget expressed as the lake’s flushing rate, and the phosphorus retention coefficient of the lake, a parameter dependent on both the lake’s morphometry and water budget, to predict springtime total phosphorus concentration in the lake. Long-term average runoff per unit of land area, precipitation, and lake evaporation data for Ontario provide a means of calculating the necessary water budget parameters without expensive and time-consuming field measurements. The predicted spring total phosphorus concentration can be used to predict the average chlorophyll a concentration in the lake in the summer, and this, in turn, can be used to estimate the Secchi disc transparency. Thus, the effects of an increase in development on a lake’s water quality can be predicted. Conversely, by setting limits for the "permissible" summer average chlorophyll a concentration or Secchi disc transparency, the "permissible" total phosphorus concentration at spring overturn can be calculated. This can be translated into "permissible" artificial load, which can then be expressed as total allowable development. This figure can be compared to the current quantity of development and recommendations made concerning the desirability of further development on the lake.

Optimal sampling period for predicting phosphores and chlorophyll concentrations in north-temperate lakes

1995 ◽  
Vol 52 (8) ◽  
pp. 1812-1815 ◽  
Author(s):  
Robert L. France ◽  
Robert H. Peters ◽  
Robert H. Rishikof
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic Status ◽  
Sampling Period ◽  
Seasonal Patterns ◽  
Optimal Sampling ◽  
Temperate Lakes ◽  
Empirical Relationships ◽  
North Temperate Lakes ◽  
Frequent Sampling

Because total phosphorus and chlorophyll a concentrations vary seasonally within north-temperate lakes, estimates of lake trophic status are usually based on several to many sampling visits. However, because such effort is not always logistically possible, the empirical relationships developed between these trophic status indicators may depend upon seasonal patterns of sampling. Clearly, it is desirable to know if some periods of the year are more likely to produce representative estimates of total phosphorus and chlorophyll a, or, alternatively, if sampling in other periods should be restricted or even avoided. Data from north-temperate lakes are used to examine the degree to which single monthly samples for total phosphorus and chlorophyll a represent seasonal means. Analyses indicate that the least precise and least accurate estimates of the means occur when single-visit synoptic surveys are conducted during April. Not until August to September do single sampling visits provide data that approximate those represented by the means garnered through more frequent sampling.

scholarly journals External Nutrient Load and Determination of the Trophic Status of Lake Ziway

2018 ◽  
Vol 3 (2) ◽  
pp. 1-16 ◽  
Author(s):  
Dessie Tibebe ◽  
Feleke Zewge Beshah ◽  
Brook Lemma ◽  
Yezbie Kassa ◽  
Ashok N. Bhaskarwar
Keyword(s):  
Chlorophyll A ◽  
Trophic State ◽  
Trophic Status ◽  
Trophic State Index ◽  
Nutrient Load ◽  
Nutrient Loads ◽  
Mean Values ◽  
State Index ◽  
The Mean ◽  
External Nutrient

Lake Ziway is shallow freshwater located in Northern part of Ethiopian Rift Valley. Expansions of the flower industry, fisheries, intensive agricultural activities, fast population growth lead to deterioration of water quality and depletion of aquatic biota. The objectives of the present study are to evaluate the spatial and temporal variations in the external nutrient load and determine the trophic status of Lake Ziway in 2014 and 2015. The nutrients and Chlorophyll-a were measured according to the standard procedures outlined in APHA, 1999. From the result Ketar and Meki Rivers catchment showed the major sources of external nutrient loads to the lake ecosystem. The mean external soluble reactive phosphorus (SRP), total phosphorus (TP), total inorganic nitrogen (TIN) and total nitrogen (TN) loads to Lake Ziway were 230, 2772, 4925 and 24016 kg day-1, respectively. A general trend which was expected that the nutrient loads would be much higher in rainy season than in dry season. The mean concentrations of trophic state variables for TN, TP and Chla were 6700, 212 and 42 mg L-1, respectively. The mean values of TSI-TP, TSI-Chl-a, TSI-TN and TSI-SD were 79, 66, 81 and 83, respectively and the overall evaluation of Carlson Trophic State Index (CTSI) of Lake Ziway was 77. Therefore, the lake is under eutrophic condition. The mean values of TN: TP ratio was 48 which were very high. The trophic state index determined with chlorophyll-a showed lower value than those determined with all trophic state indices values of TN, TP, and SD which indicated that non-algal turbidity affected light attenuation for algal growth. This suggested that phosphorus was the limiting nutrient in Lake Ziway. Due to its importance as being the lake is an intensive agricultural site, management solutions must be urgently developed in order to avoid the destruction of the lake.

Crustacean zooplankton in lakes and reservoirs of temperate and tropical regions: variation with trophic status

2005 ◽  
Vol 62 (2) ◽  
pp. 348-361 ◽  
Author(s):  
Ricardo Pinto-Coelho ◽  
Bernadette Pinel-Alloul ◽  
Ginette Méthot ◽  
Karl E Havens
Keyword(s):  
Species Richness ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Trophic Status ◽  
Zooplankton Community ◽  
Crustacean Zooplankton ◽  
Eutrophic Lakes ◽  
Crustacean Species ◽  
Tropical Regions ◽  
Lakes And Reservoirs

The influence of trophic status on the crustacean zooplankton community was investigated in lakes and reservoirs in temperate and subtropical-tropical regions. We tested if there is a consistent relationship between crustacean species richness, assemblages, and abundance and trophic indices such as total phosphorus and chlorophyll a. We also examined if these patterns differ between regions. Cumulative species richness and assemblages varied among regions. The greatest number of crustacean species was found in the temperate oligotrophic region with the largest number of lakes sampled. However, cumulative species richness was similar in temperate and subtropical–tropical regions when comparing subsets with a similar number of lakes and reservoirs. The relationships between species richness and latitude or trophic status were difficult to assess owing to imbalance among regions in number of lakes and reservoirs sampled and to biogeography and fish predation potential influences. Trophic status was associated with changes in abundance of all major crustacean zooplankton groups. Eutrophic ecosystems supported greater crustacean abundances at all latitudes. However, cladocerans and cyclopoids were more abundant in eutrophic lakes and reservoirs, whereas calanoids were more abundant in temperate oligotrophic lakes. Total phosphorus was found to be a better predictor of the biomass of major crustacean groups than chlorophyll a in all regions.

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