scholarly journals The phytoplankton community as a descriptor of environmental variability: a case study in five reservoirs of the Paraná River basin

2022 ◽  
Vol 34 ◽  
Author(s):  
Matheus Vieira da Silva ◽  
Jascieli Carla Bortolini ◽  
Susicley Jati
Keyword(s):  
Environmental Variables ◽  
Phytoplankton Community ◽  
Environmental Variability ◽  
Principal Component ◽  
Paraná River ◽  
Nutrient Concentrations ◽  
Parana River ◽  
Tietê River ◽  
River Reservoir ◽  
In Series

Abstract Aim We aimed to characterize the structure of the phytoplankton community and identify the main environmental factors driving the community in five reservoirs constructed in the region of the high Paraná River. Methods The phytoplankton and environmental variables were collected at the lacustrine region of the reservoir, between November 2013 and November 2014, with interval between collections ranged from 3 to 6 months. The richness and biomass of the phytoplankton community were measured as a response to the spatial and temporal environmental variability. Data from environmental variables was analyzed by Principal Component Analysis (PCA). Non-Metric Multidimensional Scaling Analyzes (NMDS) were performed on the richness and biomass data of the phytoplankton community. Results We identified 80 taxa distributed in 11 taxonomic classes, from which Cyanobacteria and Chlorophyceae were best represented. We did not observe significant temporal variation for either environmental variables or attributes of the phytoplankton community, which may be related to the prolonged drought in this period in the Brazilian Southwest. Higher phytoplankton richness and biomass were found in the Três Irmãos (Tiete River), reservoir located in the most anthropized basin in the country. Cyanobacteria and dinoflagellates dominated the biomass in all reservoirs during the studied period. The Ilha Solteira, Jupiá and Porto Primavera reservoirs showed a tendency to decrease in the values of phytoplankton richness and biomass, and the reservoirs built in series in the Paraná River probably have strong interdependence, according to the CRCC concept. Conclusions Spatial variation in phytoplankton attributes was influenced mainly by the position occupied by the reservoir in the hydrographic basin, water retention time (RT) and nutrient concentrations in each reservoir.

scholarly journals Phytoplankton richness and abundance in response to seasonality and spatiality in a tropical reservoir

2021 ◽  
Vol 33 ◽  
Author(s):  
Lyza Christine dos Santos Moura ◽  
Silvia Moreira dos Santos ◽  
Cláudia Alves de Souza ◽  
Carlos Roberto Alves dos Santos ◽  
Jascieli Carla Bortolini
Keyword(s):  
Environmental Variables ◽  
Environmental Variability ◽  
Hydrological Cycle ◽  
Principal Component ◽  
Ecosystem Functions ◽  
Spatial And Temporal Variation ◽  
Nutrient Concentrations ◽  
Tropical Reservoir ◽  
Rainy Period ◽  
Density Methods

Abstract: Aim Species richness and abundance are important elements in understanding communities’ dynamics. In this way we evaluated the spatial and temporal variation of phytoplankton richness and density in a tropical reservoir, and its main drivers. We tested whether the temporal variability of the hydrological cycle influences the phytoplankton, in addition to testing the main environmental variables that influence richness and density. Methods Data from environmental variables and phytoplankton were sampled in different regions of João Leite reservoir, Goiás, Brazil, during a dry and rainy period, and were analyzed by Principal Component Analysis, Student's t-test and Bioenv. Results We recorded distinct environmental scenarios between the dry and rainy period, with temporal differences in richness. Sixty-two taxa were recorded, with cyanobacterial predominance in both hydrological periods and in the lentic reservoir regions. Water temperature, pH, electrical conductivity, dissolved oxygen, turbidity, and nutrient concentrations were the main drivers of phytoplankton richness and density in our study. Conclusions The richness and abundance of species directly reflect the determining factors in the structure of communities, generating important information about ecosystem functions. Therefore, understanding the environmental variability on phytoplankton richness and abundance in tropical reservoirs is essential, since the construction of reservoirs influences aquatic biodiversity and the provision of ecosystem services.

scholarly journals Pigmented Euglenophyceae of a lentic environment at the Upper Paraná River Floodplain, Brazil

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Susicley Jati ◽  
Carla Cristiane de Jesus Borsalli ◽  
Sueli Train
Keyword(s):  
Geographical Distribution ◽  
New Records ◽  
Environmental Variability ◽  
Paraná River ◽  
Biodiversity Survey ◽  
River Floodplain ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

Abstract Aim Contributing to taxonomic knowledge on Pigmented Euglenophyceae at the Upper Paraná River Floodplain by enlarging the biodiversity survey in this ecosystem, in addition to contributing to the knowledge on the geographical distribution of this group in Brazil. Methods Quarterly samplings in the limnetic region of a floodplain lake between February 2000 and March 2009, numbering 30 samples obtained from both vertical and horizontal trawls using plankton net of a 15 µm-mesh aperture and subjected to Transeau-solution preservation. We prepared temporary slides and analyzed in order to have the organisms identified, measured and photographed through digital camera, directly using an Olympus binocular optical microscope with a 400x/1000x magnification. The analysis included the calculation of Constancy (C) for the sample of each species. Results 36 taxa were identified. Genus Trachelomonas Ehr. emend. Defl. had the best representation, with 20 taxa. Among the taxa surveyed, 53% (19 taxa) constituted new records of occurrence for the Upper Paraná River Floodplain. The taxa recorded as frequent (33.3%) are considered cosmopolitan and present wide geographical distribution throughout Brazil; however, most of the taxa surveyed (67%) was classified as sporadic or rare, which is probably related to the high environmental variability observed along the study period. Conclusion Among the surveyed 19 taxa constituted new records of occurrence for the upper Paraná River floodplain and extended the geographical distribution of Euglenophyceae in Brazil.

scholarly journals Nutrient Concentrations in Macrophytes from Lotic and Lentic Environments of the Middle Parana River, Argentina

2021 ◽  
Vol 25 ◽  
Author(s):  
Hernán Ricardo Hadad ◽  
María Alejandra Maine ◽  
María de las Mercedes Mufarrege ◽  
Gisela Alfonsina Di Luca ◽  
Gabriela Cristina Sanchez
Keyword(s):  
Paraná River ◽  
Nutrient Concentrations ◽  
River Floodplain ◽  
Parana River ◽  
Water And Sediment ◽  
Lotic Environment ◽  
Lotic Environments ◽  
Paraná River Floodplain ◽  
Kjeldahl Nitrogen ◽  
Middle Paraná

Objectives: The purpose of this work was to compare nutrient concentrations in water, sediment, and in plant tissues of Eichhornia crassipes and Panicum elephantipes from lotic and lentic environments of the Middle Parana River floodplain (Argentina). Materials and Methods: The study was carried out over an 18-month period. Plants, water, and sediment were collected in a lake (lentic environment) and in a river (lotic environment) from the Middle Parana River floodplain. Water and sediment were sampled in sites where P. elephantipes or E. crassipes were predominant and in sites without vegetation. Results and Discussion: The lentic and lotic environments dominated by E. crassipes showed the highest ammonium concentrations. The sediment from the lotic environment showed total phosphorus (TP) and total Kjeldahl nitrogen (TKN) concentrations significantly lower than those found in the sediment from the lentic environment. In the lentic environment, the sediment from the lake with the dominance of E. crassipes showed the highest TKN concentration, while the sediment from the lake dominated by P. elephantipes showed the highest TP concentration. For both plant species and for both environments, TKN and TP tissue concentrations were significantly higher in leaves in comparison with roots. Conclusions: Our results could be used to optimize the efficiency of treatment wetlands. Additionally, the use of locally available macrophytes as contaminant bioaccumulators in the Middle Parana River floodplain is completely feasible.

scholarly journals Fish larvae from the upper Paraná River: do abiotic factors affect larval density?

2008 ◽  
Vol 6 (4) ◽  
pp. 551-558 ◽  
Author(s):  
Gilmar Baumgartner ◽  
Keshiyu Nakatani ◽  
Luiz Carlos Gomes ◽  
Andréa Bialetzki ◽  
Paulo Vanderlei Sanches ◽  
...  
Keyword(s):  
Fish Larvae ◽  
Abiotic Factors ◽  
Larval Density ◽  
Principal Component ◽  
Paraná River ◽  
The Other ◽  
Parana River ◽  
Upper Paraná River ◽  
Iheringichthys Labrosus

The purpose of this study was to evaluate the role of abiotic factors on fish larvae occurrence. Samplings were carried out monthly at 12 stations (grouped in four areas) in the Amambaí, Ivaí and Paraná rivers and in the Itaipu Reservoir (upper Paraná River basin), from October 1994 to January 1995 (spawning season). Simultaneously, we obtained water temperature, pH, electrical conductivity, dissolved oxygen, water level, water velocity, and rainfall. Principal Component Analyses (PCA) and Detrended Correspondence Analyses (DCA) were applied to summarize abiotic and larvae density data, respectively. Amambaí River differed significantly from the other areas in relation to abiotic factors. Itaipu Reservoir differed significantly from the other areas considering species composition, and the Ivaí River also differed from the Paraná River. The relationship among PCA and DCA axes were significant, indicating that abiotic factors do influence larva. For example: Leporinus elongatus prefered the Amambaí River, Hypophthalmus edentatus, Plagioscion squamosissimus, and Hoplias aff. malabaricus the Itaipu Reservoir, and Pimelodus maculatus, Auchenipterus osteomystax and Iheringichthys labrosus the Ivaí River. We suggest that species selected some abiotic factors characteristic to a given environment as spawning grounds.

scholarly journals Periphytic algae of the Garças Lake, Upper Paraná River floodplain: comparing the years 1994 and 2004

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 459-468 ◽  
Author(s):  
EA. Murakami ◽  
DC. Bicudo ◽  
L. Rodrigues
Keyword(s):  
Environmental Changes ◽  
Hydrological Regime ◽  
Paraná River ◽  
Nutrient Concentrations ◽  
River Floodplain ◽  
Periphytic Algae ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

The changes imposed by dams on hydrological regime, water transparence and nutrient concentrations downstream affect biodiversity in relation to species richness and specific composition of the community. The aim of this work was evaluate this effect on periphyton, comparing richness and composition of periphytic algae in the Garças Lake, Upper Paraná River floodplain, between the years 1994, before construction of the Porto Primavera Reservoir, and after its operation in 2004. This floodplain lake showed an increase in species, from 113 in 1994 to 159 in 2004. A few species, however, were common during the last year, dominated by Zygnemaphyceae and some Bacillariophyceae species. The increase in algal diversity in 2004 may be the result of the ability of the system to adapt to environmental changes. However, the large change in the periphyton species composition suggests further impacts on the food web, demanding continuity of long-term studies in order to determine their consequences on the biodiversity as a whole.

scholarly journals Effects of nutrients increase on the copepod community of a reservoir using cages

2015 ◽  
Vol 27 (3) ◽  
pp. 265-274 ◽  
Author(s):  
Vanessa Graciele Tibúrcio ◽  
Rodrigo Leite Arrieira ◽  
Leilane Talita Fatoreto Schwind ◽  
Claudia Costa Bonecker ◽  
Fábio Amodêo Lansac-Tôha
Keyword(s):  
Final Stage ◽  
Environmental Variables ◽  
Initial Conditions ◽  
Spatial Scales ◽  
Principal Component ◽  
Fish Farming ◽  
Nutrient Concentrations ◽  
System Productivity ◽  
Copepod Abundance ◽  
Significant Difference

Abstract Aim: This study investigated changes in copepod abundance and the influence of environmental variables in a reservoir with fish farming using cages, on temporal and spatial scales. We hypothesised that the copepod abundance will increase when influenced by changes in environmental variables due the increase of nutrients originating from fish farming. Methods A 120-day sampling of copepods and environmental variables was carried out in a subtropical reservoir of the Paraná River basin (Rosana reservoir), upstream and downstream of three sets of cages with different fish stocking densities. A Principal Component Analysis was conducted to characterise sampling periods and points through environmental variables. The differences between copepod abundance according to sampling periods and points were tested by ANOVA. Results We observed higher maximum values for most nutrient concentrations and dissolved oxygen in the final stage of the experiment and in the location of cages installation. The copepod abundance increased sharply during the first days of the experiment and then decreased during the following periods with a tendency towards returning to the initial conditions at the final stage of the experiment. A significant difference in copepod abundance between the location of cages installation and downstream was showed. In addition, turbidity, chlorophyll-a, and nitrate significantly predicted copepod abundance. Conclusion The results suggested that the changes in copepod abundance over time are influenced by environmental variables, evidenced by the increase in nutrient concentration after the cage installation, related to the increase in the practice of fish farming. The environmental variables related to system productivity were linked to the availability of food resources. Thus, our hypothesis that copepod abundance is increased due the alterations in environmental variables caused by the increase in the practice of fish farming using cages was corroborated.

scholarly journals Environmental variables driving the larval distribution of Limnoperna fortunei in the upper Paraná River floodplain, Brazil

2017 ◽  
Vol 29 (0) ◽  
Author(s):  
Jéssica Ernandes-Silva ◽  
Gisele Daiane Pinha ◽  
Roger Paulo Mormul
Keyword(s):  
Water Temperature ◽  
Environmental Variables ◽  
Paraná River ◽  
Limnoperna Fortunei ◽  
River Floodplain ◽  
Larval Stages ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

Abstract Aim: To verify the temporal dynamics of Limnoperna fortunei larval stages and to identify the main environmental variables driving the larval density patterns in an area highly impacted by reservoirs. Methods Samplings were performed quarterly, from February to December 2014, in 10 transects along to the Paraná River main channel. For each sample site, 100 L of water were filtered. The filtrated was fixed in alcohol 80%, and the larval stages were counted and classified under the optical microscope. Concomitant to biological collections we took some of the main water variables. We performed a Redundancy Analysis (RDA) in order to summarize the variations in densities of larval stages in relation to the main physical and chemical water variables. Results We found a total of 200,590 L. fortunei larvae, in which 83.6% were identified as the initial stages. The most abundant months in L. fortunei larvae were December and February. The first two axes of RDA sum up 96% of the total data variation, and the most significant environmental variables explaining variations in larval densities were: water temperature, total nitrogen, electrical conductivity, phosphate, dissolved oxygen, depth and ammoniac ion. The warmer months were influenced by the major values of water temperature and depth, besides the higher densities of all larval stages. Conclusions Our results indicate that L. fortunei reproduction follows a general pattern throughout the upper Paraná River floodplain, what seems to occur mainly between February and December. Thus, we suggest that measures for the L. fortunei control should be done during low-density periods (i.e., April to August), when the water level is low, and consequently, the dispersion of this species might be limited.

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