scholarly journals Longitudinal processes in Salto Grande reservoir (Americana, SP, Brazil) and its influence in the formation of compartment system

2002 ◽  
Vol 62 (2) ◽  
pp. 347-361 ◽  
Author(s):  
L. H. ZANATA ◽  
E. L. G. ESPÍNDOLA
Keyword(s):  
Longitudinal Axis ◽  
Chemical Oxidation ◽  
Sampling Station ◽  
Longitudinal Gradient ◽  
Compartment System ◽  
Rainy Period ◽  
Operational Mechanism ◽  
Biological Variables ◽  
Physical Chemical ◽  
Concentration Degree

Studies on the longitudinal processes in reservoirs, involving physical, chemical and biological processes have been thoroughly appraised, suggesting the existence of a longitudinal organization controlled by the entrance and circulation of water which inserts modifications in the structuring of the system. To evaluate this effect, the Salto Grande reservoir (Americana, SP) was analyzed in 11 sampling stations in its longitudinal axis, in the rainy and dry seasons of 1997 considering the physical chemical and biological variables. Analyzing the results in agreement with the declining concentration degree of the river--barrage direction, a more significant correlation was verified in the dry period for total phosphorus (r² = 0.86), dissolved total phosphate (r² = 0.83), nitrite (r² = 0.93), inorganic phosphate (r² = 0.89), ammonium (r² = 0.84) and suspended material (r² = 0.85). In the rainy period, only nitrite (r² = 0.90) and conductivity (r² = 0.89) presented correlation with the distance of the dam, which demonstrates the effects of precipitation and the operational mechanism of the dam, as well as the distinction among the physical (sedimentation), chemical (oxidation) and biological (decomposition) processes in spatial heterogeneity of the system. These factors were decisive in the organization of these communities, with higher occurrence of rotifers and copepods in relation to cladocerans, the first ones being more abundant in the entrance of the Atibaia river, decreasing towards the dam direction, while copepods presented an inverse pattern. A distribution pattern similar to Copepoda was also verified for the Cladocera, evidencing a tendency to increase the density of organisms in the stations distant to the entrance of the Atibaia river, not being registered, however, a distribution gradient in the longitudinal axis, as observed for rotifers and copepods. In relation to the trophic degree a longitudinal gradient was also verified from eutrophic to oligotrophic depending on the location of the sampling station in relation to the longitudinal axis and period of analysis. The differences obtained, relating to the distribution of the environmental variables, demonstrate a characteristic pattern for reservoirs, with a longitudinal gradient in the sense river--barrage that inserts changes in the physical and chemical composition of the water, contributing to the differentiated establishing of biological communities.

scholarly journals Effects of Weir Construction on Phytoplankton Assemblages and Water Quality in a Large River System

2018 ◽  
Vol 15 (11) ◽  
pp. 2348 ◽  
Author(s):  
Hae-Jin Lee ◽  
Hae-Kyung Park ◽  
Se-Uk Cheon
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
River System ◽  
Large River ◽  
Anthropogenic Factors ◽  
Centric Diatom ◽  
Nakdong River ◽  
Biological Variables ◽  
Physical Chemical ◽  
The Nakdong River

Flow regulation is one of the most common anthropogenic factors affecting rivers worldwide. In Korea, 16 weirs were constructed along four major rivers from 2009 to 2012. This study aimed to elucidate initial changes in physical, chemical, and biological variables after the construction of consecutive weirs on the Nakdong River, a major large river system. Water quality variables and phytoplankton cell densities were investigated at eight representative sites and compared with the data recorded before the weir construction. There were spatial and temporal changes in the hydraulic retention time (HRT), total phosphorus (TP), and chlorophyll a concentrations among the eight weir sections. HRT increased after the weir construction, while TP and chlorophyll a tended to decrease from the middle to lower section of the Nakdong River. Furthermore, differences were observed in the phytoplankton community composition between 2006–2007 and 2013. There was a marginal decrease in the duration of centric diatom (Stephanodiscus hantzschii) blooms after weir construction. However, Microcystis aeruginosa proliferated more extensively during summer and autumn than it did before the weir construction. Our results suggest that changes in hydrological factors, in response to consecutive weir construction, may contribute to greater physical, chemical, and ecological variability.

scholarly journals The response of Carlos Botelho (Lobo, Broa) reservoir to the passage of cold fronts as reflected by physical, chemical, and biological variables

2004 ◽  
Vol 64 (1) ◽  
pp. 177-186 ◽  
Author(s):  
J. G. Tundisi ◽  
T. Matsumura-Tundisi ◽  
J. D. Arantes Junior ◽  
J. E. M. Tundisi ◽  
N. F. Manzini ◽  
...  
Keyword(s):  
Management Strategies ◽  
Vertical Mixing ◽  
Continuous System ◽  
Cyanobacterial Blooms ◽  
Metropolitan Region ◽  
Climatological Data ◽  
Cold Fronts ◽  
Biological Variables ◽  
Physical Chemical ◽  
Shallow Reservoirs

This paper describes and discusses the impacts of the passage of cold fronts on the vertical structure of the Carlos Botelho (Lobo-Broa) Reservoir as demonstrated by changes in physical, chemical, and biological variables. The data were obtained with a continuous system measuring 9 variables in vertical profiles in the deepest point of the reservoir (12 m) coupled with climatological information and satellite images, during a 32-day period in July and August, 2003. During periods of incidence of cold fronts the reservoir presented vertical mixing. After the dissipation of the cold fronts a period of stability followed with thermal, chemical, and biological (chlorophyll-a) stratification. Climatological data obtained during the cold front passage showed lower air temperature, higher wind speed and lower solar radiation. The response of this reservoir can exemplify a generalized process in all shallow reservoirs in the Southeast Brazil and could have several implications for management, particularly in relation to the phytoplankton population dynamics and development of cyanobacterial blooms. Using this as a basis, a predictive model will be developed with the aim of advancing management strategies specially for the drinking water reservoirs of the Metropolitan Region of São Paulo.

The response of reservoirs of southeastern Brazil to the passage of cold fronts as reflected by physical, chemical and biological variables

2006 ◽  
Vol 29 (4) ◽  
pp. 2124-2128
Author(s):  
J.G. Tundisi ◽  
N.Y. Sebastien ◽  
T. Matsumura-Tundisi ◽  
J.E.M. Tundisi ◽  
N.F. Manzini
Keyword(s):  
Southeastern Brazil ◽  
Cold Fronts ◽  
Biological Variables ◽  
Physical Chemical

scholarly journals Limnological characteristics of a hydrographic basin of the Brazilian semiarid region

2015 ◽  
Vol 27 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Rodrigo Sávio Teixeira de Moura ◽  
Gustavo Gonzaga Henry-Silva
Keyword(s):  
Water Quality ◽  
Oxygen Demand ◽  
Semiarid Region ◽  
Aquatic Environments ◽  
Anthropogenic Pressures ◽  
Longitudinal Gradient ◽  
Rainy Period ◽  
Hydrographic Basin ◽  
Water Characteristics ◽  
High Concentrations

AimThis study aimed to verify if the water characteristics of Apodi/Mossoró River basin aquatic environments are mainly determined by a longitudinal gradient or its rain regime.MethodsThrough one year quarterly sample expeditions were carried (August/2007 to May/2008), in 24 sampling stations. In each place, water samples were collected and direct parameters were measured. Concentrations of nutrients, biochemical oxygen demand and thermotolerant coliforms were determined. For ordination of the sampling stations and in order to find patterns in water quality was conducted a Principal Components Analysis.ResultsThe results showed that points inside urban agglomerates had depreciated water quality, with high concentrations of nutrients. In general, it was not possible to define a longitudinal gradient for the studied variables, probably due to anthropogenic interferences along the basin. Otherwise, the effect of rainy and dry seasons were marked, resulting in a grouping of the sampling stations during the dry months, mainly due to the raised values of nutrients and biochemical oxygen demand.ConclusionIt could be concluded that in the rainy period a homogenizer effect occurred, not being verified the zonation of the hydrographic basin aquatic environments. The anthropogenic pressures probably contributed for the absence of a longitudinal gradient, since they generate disorders which modify the aquatic environments.

scholarly journals Evaluación, Física, Química y Biológica de compostas tipo bocashi elaboradas con estiércol de bovino, ovino, cerdo y conejo más una vermicomposta

2019 ◽  
pp. 33-40
Author(s):  
Alicia De Luna-Vega ◽  
María Luisa García-Sahagún ◽  
Enrique Pimienta-Barrios ◽  
Eduardo Rodríguez-Guzmán
Keyword(s):  
Seed Germination ◽  
Root Development ◽  
Indoleacetic Acid ◽  
Biological Variables ◽  
Physical Chemical ◽  
Minimum Requirements ◽  
Agronomic Quality ◽  
Organic Compost

Some composts can produce phytotoxins that inhibit the development of plants and the absorption of nutrients by an excess of indoleacetic acid if the compost is not mature. In the present work, the objective is to evaluate the quality of the compost by means of direct tests of phytotoxicity and agronomic quality with different composts. To determine the quality as organic compost and vermicompost fertilizer were considered physical, chemical and biological variables according to existing manuals. The results obtained for these variables were: In the physical, chemical and biological variables, all the parameters are fulfilled according to the norm. Seed germination of vegetables increased with respect to the control in 14.93%, possibly due to the presence of some root development promoter found in the compost. With regard to survival the witness was inferior by 3.08% Although the amount of nutrients found in composts are not so high, they comply with the minimum requirements of the regulations to be used as a substrate in horticultural applications. Conclusion, the results of this study indicate that the compost elaborated with any type of residue can be used as a substrate in seedbeds of chili, onion or other vegetables to induce germination and accelerate the development of plants.

scholarly journals RELACIONES CONTEMPORANEAS Y REZAGADAS ENTRE VARIABLES FISICOQUIMICAS Y BIOLOGICAS EN LA CIENAGA GRANDE DE SANTA MARTA, CARIBE COLOMBIANO

2016 ◽  
Vol 27 ◽  
Author(s):  
Sven Zea ◽  
Ramón Giraido H. ◽  
José Ernesto Mancera P ◽  
Jorge Martínez C.
Keyword(s):  
Primary Production ◽  
Total Nitrogen ◽  
Phytoplankton Biomass ◽  
Apparent Lack ◽  
Biological Variables ◽  
Physical Chemical ◽  
Generation Times ◽  
Mean And Variance ◽  
Cross Correlations ◽  
Time Lagged

From available data from four sampling stations at Ciénaga Grande de Santa Marta coastal lagoon (Colombian Caribbean), contemporary and time-lagged cross-correlations between biweekly series of "biological" variables (chrolophyll a, primary productivity) and "physical-chemical" variables (salinity, transparency, inorganic nutrientes, total nitrogen and phosphorous, phaeopigments, seston proteins) were explored. In contrast with the original analyses, turning series stationary (constant mean and variance) eliminated variations in trend and magnitude associated with climate, and emphasized variation at the scale of weeks. As a result, changes in primary production were not related either with contemporary changes in phytoplankton biomass (measured as chlorophyll a) or with previous or contemporary changes in physical chemical variables. This apparent lack of effect of the inorganic nutrients regime on the primary production may occur because nutrient availability is the dinamyc result of uptake and recycling. Only, increases in total nitrogen were associated with rises in primary production 4 weeks later, possibly from lagged used of reserves by phytoplankton. Variations in phytoplankton biomass were positively correlated with contemporary changes in dissolved phosphorous, and negatively with changes in transparency. The first relation could be caused by phosphorous liberation from the benthos in nocturnal anoxic conditions during massive blooms. The second may occur because the main agent conditioning water transparency is phytoplankton. In contrast, increases in primary production were followed by decreases in dissolved nitrogen and phosphorous two weeks later, again possibly in relation to phytoplankton generation times and the dynamics of uptake and recycling.

scholarly journals Physico-chemical Factors an Phytoplankton as Indicators of the Water Quality in Two Periurbans Lakes of a Natural Protected Area in Mexico City

2021 ◽  
Vol 2 (5) ◽  
pp. 60-65
Author(s):  
J. R. Latournerié-Cervera ◽  
A. R. Estrada-Ortega ◽  
A. K. Escobar-Álvarez ◽  
A. J. Quino-Trejo ◽  
R. G. Barrera-Pastrana ◽  
...  
Keyword(s):  
Water Quality ◽  
Mexico City ◽  
Fixed Effects ◽  
Statistical Design ◽  
Sampling Station ◽  
Measured Temperature ◽  
Lake System ◽  
Physical Chemical ◽  
Chemical Factors ◽  
The Impact

The protected natural area (ANP), Ejidos de Xochimilco and San Gregorio Atlapulco (SGA), is a priority area of ecological conservation in Mexico City (CDMX), that still have remnants of the ancient lake system of the Valley of Mexico watershed that have been modified for decades due to the impact of human activities and that threaten their continuity, despite been declared as a RAMSAR site and historical and cultural heritage of CDMX. Given the above, the present study aimed to compare the spatial-temporal variability of physical-chemical factors and phytoplankton as indicators of anthropogenic impact to diagnose the current state of this locality and propose possible alternatives for sustainable management in the study area. The research design considered comparing the area of channels and lagoons of the SGA wetland in two contrasting climatic seasons: dry and rainy. Eleven sampling stations were delimited: three in the channels area and eight in the lagoons, during the months of March and July. Nine physical-chemical variables were measured: temperature, pH, total solids, conductivity, dissolved oxygen, as well as the concentrations of ammonium, nitrites, nitrates, and soluble phosphorus in surface and bottom samples from each sampling station. The statistical design took into account a factorial design of fixed effects (epochs - locations and strata), with Tukey's "post hoc" test to delimit subsets and various multivariate analysis techniques. Phytoplankton samples were taken in both localities, which were identified down to the genus level, evaluating the relative frequency of the various taxa, as well as their association through the saprobity and diversity indexes. The water quality variables indicated that both the area of channels and the lagoons of the wetland are sites with hypereutrophic characteristics, but the wetland due to its semi-isolation is an area that presents on average levels of nitrates 2.4 times lower than in the channel zone, nitrite concentrations are almost imperceptible, and ammonia is within tolerable limits for the existing biota. It also presents space-time homogeneity in its physical-chemical dynamics, in contrast to the area of channels. The composition of species indicating saprobity also differed between both sites, denoting a lesser impact on the wetland area, so it is suggested to use this site for reintroduction activities of species removed from the channel area and preserve the remaining biota in the lake system.

scholarly journals Spatial and temporal variations in fish assemblage: testing the zonation concept in small reservoirs

2017 ◽  
Vol 78 (3) ◽  
pp. 487-500 ◽  
Author(s):  
M. T. Baumgartner ◽  
G. Baumgartner ◽  
L. C. Gomes
Keyword(s):  
Species Richness ◽  
Fish Assemblage ◽  
Longitudinal Axis ◽  
Temporal Variations ◽  
High Variability ◽  
Longitudinal Gradient ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Small Reservoirs ◽  
Spatial Gradients

Abstract Large reservoirs usually present spatial gradients in fish assemblage, distinguishing three strata (littoral, pelagic, and bathypelagic) along the vertical and horizontal axes, and three zones (fluvial, transitional, and lacustrine) along the longitudinal axis. The main objective of this study was to assess if small reservoirs also present the spatial gradients in fish assemblage attributes and structure as already observed in large reservoirs. Fish surveys were conducted quarterly, from 2003 to 2008, in the Mourão Reservoir (Mourão River, Paraná, Brazil), using gillnets with different mesh sizes, arranged in all strata of all three zones. Community attributes (species richness and evenness) were calculated for each sample, and differences were tested using three-way ANOVA (factors: zone, strata, year). Community composition was summarized using Correspondence Analysis (CA) and differences were tested with three-way ANOVA for each axis, controlling the same three factors. Because of the high variability in reservoir water level through time, all analyses were made considering temporal variations. Species richness presented a decreasing trend from fluvial to lacustrine zones, and higher values in littoral strata, possibly because upper reaches and littoral regions provide better conditions for fish to feed and to reproduce. Evenness was considerably low, presenting high variability, and no evident pattern. The expected longitudinal gradient was not found in this study indicating longitudinal similarity, contrary to observed in large reservoirs. Vertical and horizontal gradients were observed in all sampling stations, indicating that abiotic and biotic conditions are influencing fish distributions within the reservoir.

scholarly journals Importance of lateral lagoons for the ichthyofauna in a large tropical reservoir

2011 ◽  
Vol 71 (4) ◽  
pp. 807-820 ◽  
Author(s):  
M. Ferrareze ◽  
MG. Nogueira
Keyword(s):  
Habitat Complexity ◽  
Fish Assemblages ◽  
Aquatic Macrophyte ◽  
Mesh Size ◽  
Small Fish ◽  
Sampling Station ◽  
Tropical Reservoir ◽  
Rainy Period ◽  
Importance Index ◽  
Se Brazil

This study aimed to analyse the composition and the ecological attributes of small-sized fish assemblages in four lagoons and in the main channel of Rosana Reservoir (SE Brazil). Fieldwork was carried out in September and November/2004 and January, March, May and August/2005. In each sampling station and period five manual throws were performed towards aquatic macrophyte stands, using a hand net (1.5 × 5 m; 0.3 cm of mesh size). The ichthyofauna collected was represented by 42 species, totalizing 3,424 individuals, 2,186 g in weight. The order Characiformes was dominant, mainly in the lagoons with low connectivity with the river. The main taxon (Importance Index) was Hemigrammus marginatus. Higher richness, abundance, biomass, diversity and lower individual mean length were observed in the lagoons, especially during the rainy period. Spatial segregation of some species was showed by the canonical correspondence analysis indicating the habitat complexity. The results validate the hypotheses that lateral lagoons have a prominent ecological role in the life cycle of juveniles and small fish and demonstrate how the connectivity river/lagoons may be important for assemblages maintenance.

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