scholarly journals Biomonitoring ecological status of two reservoirs of the Brazilian semi-arid using phytoplankton assemblages (Q index)

2015 ◽  
Vol 27 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Ana Paula Cardoso Silva ◽  
Ivaneide Alves Soares da Costa
Keyword(s):  
Phytoplankton Community ◽  
Ecological Status ◽  
Sample Period ◽  
Phytoplankton Composition ◽  
Santa Cruz ◽  
Phytoplankton Assemblages ◽  
Total Phytoplankton ◽  
Moderate Condition ◽  
Q Index ◽  
Semi Arid

AimAssess whether the assembly index is a suitable tool for biomonitoring of aquatic ecosystems of semi-arid environment.MethodsMonthly, samples were collected between October 2011 and May 2012 in Santa Cruz do Apodi (5°43'59"S; 46" 00 119 "W) and Pau dos Ferros (6°08'30.12" S; 038°10'59 880"W) reservoirs.ResultsThe Pau dos Ferros reservoir, shallow, turbid and eutrophic showed dominance of the functional group SN throughout the sample period. Total phytoplankton biovolume ranged between 20 and 70 mm³.L–1, the lowest values coincided with the increase of the mixing zone and transparency, which occasioned a change in composition of the phytoplankton community. Pau dos Ferros reservoir was categorized as poor for most of the sample period. The Santa Cruz do Apodi reservoir was characterized as meso-eutrophic, exhibiting low total phytoplankton biovolume (0.04 to 0,4 mm³.L–1) and greater diversity in the phytoplankton composition. It showed moderate condition during most of the period.ConclusionIn summary, the index Q reflected well the changes in phytoplankton composition, being a good indicator for biomonitoring of these systems.

scholarly journals Phytoplankton functional groups in shallow aquatic ecosystems from the semiarid region of Brazil

2021 ◽  
Vol 33 ◽  
Author(s):  
Klivia Rilavia Paiva da Silva ◽  
José Etham de Lucena Barbosa ◽  
Lucineide Maria Santana ◽  
Luciana Gomes Barbosa
Keyword(s):  
Functional Groups ◽  
Aquatic Ecosystems ◽  
Abiotic Factors ◽  
Ecological Status ◽  
Semiarid Region ◽  
Control Mechanisms ◽  
Phytoplankton Composition ◽  
Brazilian Semiarid ◽  
Phytoplankton Functional Groups ◽  
Q Index

Abstract: Aim The study analyzed the potential use of the phytoplankton functional groups as an environmental bioindicator in aquatic ecosystems of Brazilian semiarid region. Methods Using data collected over five years of a natural lagoon and two reservoirs, we evaluate the relationship between functional groups and environmental conditions through the multivariate approach. The Q index was applied to assess ecological status in these ecosystems. Results In Panati, the temporary and natural lagoon, the partial habitat desiccation and presence of macrophytes reflected in the less nutrients concentrations and phytoplankton composition, with high biomass of coccoids Chlorophyceae, diatoms and desmids (functional groups J, MP and N, respectively). Taperoá and Soledade reservoirs presented high cyanobacteria contribution, however the biomass and contribution of cyanobacteria in Taperoá (SN, S1) were lower than in Soledade. In this reservoir, cyanobacteria were more abundant, alternating in dominance (LO, M, LM, SN, S1). According to tendencies revealed by Redundancy Analysis (RDA), the main driving abiotic factors on the phytoplankton functional groups were pH, nutrients and light availability. As expected, phytoplankton composition directly influenced the Q index result, showing mostly bad to tolerable conditions in Soledade, medium to good in Taperoá and good to excellent in Panati. Conclusions The Q index was a good tool to assess the water quality and ecological status in aquatic ecosystems from the Brazilian semiarid region, reflecting the influence of natural control mechanisms on the harmful cyanobacteria blooms in temporary ecosystems.

scholarly journals Vertical and temporal dynamics of phytoplanktonic associations and the application of index assembly in tropical semi-arid eutrophic reservoir, northeastern Brazil

2015 ◽  
Vol 27 (1) ◽  
pp. 130-144 ◽  
Author(s):  
Pryscila Cynara Soares Vieira ◽  
Maria Marcolina Lima Cardoso ◽  
Ivaneide Alves Soares da Costa
Keyword(s):  
Dissolved Oxygen ◽  
Water Temperature ◽  
Functional Groups ◽  
Phytoplankton Community ◽  
Temporal Dynamics ◽  
Temporal Variations ◽  
Northeastern Brazil ◽  
Quality Of Water ◽  
Q Index ◽  
Semi Arid

AimTo determine the composition and biomass of functional groups around the vertical and temporal gradient correlated with environmental conditions and apply the index Q in a water-supply reservoir.MethodsWater samples were collected monthly (n = 92) between 2009 and 2011 in two points of the dam for physicochemical and biological analysis.ResultsThe pH, dissolved oxygen and water temperature showed significant differences between the photic and aphotic zones (p<0.05). The vertical variation of dissolved oxygen and water temperature, showed a profile of stratification. The phytoplankton community was represented by 11 functional groups: S1, M, H1, Lo, P, F, SN, J, W2, MP and R.ConclusionsThe vertical variations were less pronounced than the temporal variations in the phytoplankton community. The Q index pointed out poor water quality, corresponding to the current state of eutrophication in the reservoir and it was sensitive to responsive to environmental and hydrodynamic changes in these systems, demonstrating to be an appropriate tool for monitoring and evaluating the quality of water in tropical semi-arid reservoirs.

Variation in climate determines differences in the effects of abiotic variables on the phytoplankton community in tropical ecosystems

2018 ◽  
Vol 69 (3) ◽  
pp. 357
Author(s):  
F. H. Portella Corrêa de Oliveira ◽  
A. N. Moura ◽  
Ê. W. Dantas
Keyword(s):  
Phytoplankton Community ◽  
Synergistic Effects ◽  
Climatic Conditions ◽  
Cylindrospermopsis Raciborskii ◽  
Tropical Reservoirs ◽  
Physicochemical Variables ◽  
Abiotic Variables ◽  
Tropical Climates ◽  
Semi Arid ◽  
Canonical Analyses

The present study demonstrates the effects of abiotic variables on phytoplankton in two different tropical climates. Samples were taken from tropical reservoirs, including six from a tropical climate (As) and five from a semi-arid climate (BSh). Phytoplankton samples were identified, biomass was quantified and climatic and physicochemical variables were evaluated. Canonical analyses were performed in order to observe the effects of abiotic variables on phytoplankton. In both As and BSh ecosystems, the effects of the physicochemical variables were significant, but the synergistic effects between variables and climatic conditions were more pronounced in BSh. Micronutrients had a significant role in structuring the phytoplankton community in both As and BSh. In As, Cylindrospermopsis raciborskii occurred in the presence of lower concentrations of zinc and copper, whereas in BSh this species was present in the presence of higher concentrations of zinc. In the As climate, Geitlerinema amphibium, Cyclotella meneghiniana, Planktothrix agardhii and Microcystis aeruginosa were associated with higher sodium concentrations in the water, whereas in the BSh climate these species experienced lower rainfall. The findings of the present study show that climate determines the effects of abiotic variables on the phytoplankton community in both an independent and synergistic manner. In the present study, phytoplankton in tropical and semi-arid reservoirs is mostly regulated by nutrients, the effects of which vary according to climate.

scholarly journals Multi-gauge Calibration for Modeling the Semi-Arid Santa Cruz Watershed in Arizona-Mexico Border Area Using SWAT

2012 ◽  
Vol 5 ◽  
pp. ASWR.S9410 ◽  
Author(s):  
Rewati Niraula ◽  
Laura M. Norman ◽  
Thomas Meixner ◽  
James B. Callegary
Keyword(s):  
Assessment Tool ◽  
Soil Layer ◽  
Watershed Modeling ◽  
Base Flow ◽  
Shallow Aquifer ◽  
Return Flow ◽  
Monitoring Site ◽  
Santa Cruz ◽  
Mexico Border ◽  
Semi Arid

In most watershed-modeling studies, flow is calibrated at one monitoring site, usually at the watershed outlet. Like many arid and semi-arid watersheds, the main reach of the Santa Cruz watershed, located on the Arizona-Mexico border, is discontinuous for most of the year except during large flood events, and therefore the flow characteristics at the outlet do not represent the entire watershed. Calibration is required at multiple locations along the Santa Cruz River to improve model reliability. The objective of this study was to best portray surface water flow in this semi-arid watershed and evaluate the effect of multi-gauge calibration on flow predictions. In this study, the Soil and Water Assessment Tool (SWAT) was calibrated at seven monitoring stations, which improved model performance and increased the reliability of flow predictions, in the Santa Cruz watershed. The most sensitive parameters to affect flow were found to be curve number (CN2), soil evaporation and compensation coefficient (ESCO), threshold water depth in shallow aquifer for return flow to occur (GWQMN), base flow alpha factor (ALPHA_BF), and effective hydraulic conductivity of the soil layer (CH_K2). In comparison, when the model was established with a single calibration at the watershed outlet, flow predictions at other monitoring gauges were inaccurate. This study emphasizes the importance of multi-gauge calibration to develop a reliable watershed model in arid and semi-arid environments. The developed model, with further calibration of water quality parameters will be an integral part of the Santa Cruz Watershed Ecosystem portfolio Model (SCWEPM), an online decision support tool, to assess the impacts of climate change and urban growth in the Santa Cruz watershed.

scholarly journals Phytoplankton community of a polymictic reservoir, La Plata River basin, Uruguay

1999 ◽  
Vol 59 (4) ◽  
pp. 535-541 ◽  
Author(s):  
M. C. PÉREZ ◽  
S. BONILLA ◽  
G. MARTÍNEZ
Keyword(s):  
Spatial Heterogeneity ◽  
River Basin ◽  
Phytoplankton Community ◽  
Water Reservoir ◽  
Phytoplankton Composition ◽  
Phytoplankton Abundance ◽  
La Plata ◽  
Phytoplankton Distribution ◽  
Aulacoseira Granulata

This paper deals with the analysis of phytoplankton composition and abundance from four sampling stations at the polymictic system, Rincón del Bonete water reservoir in Uruguay. Sampling data were obtained in 4 seasonal periods between February and November 1993. A hundred and twenty-four taxa were identified, where Aulacoseira granulata (Ehrenb.) Simon., A. granulata var. angustissima (Muller) Simon., A. granulata var. angustissima f. spiralis, (Muller) Simon., A. cf. ambigua, (Grun.) Simon., A. cf.. distans (Ehrenb.) Simon., Cryptomonas spp. and Synedra ulna (Nitzsch) Ehrenberg, were always present. Phytoplankton abundance fluctuated between 29 (autumn) and 2129 (summer) ind/ml. The general dominance of Aulacoseira spp. could be related to the polymictic condition of the system. In cold months phytoplankton distribution was homogeneous among sampling stations, while in warm months, spatial heterogeneity was detected, suggesting that sampling stations can behave as independent compartments.

scholarly journals Phytoplankton abundance, dominance and coexistence in an eutrophic reservoir in the state of Pernambuco, Northeast Brazil

2011 ◽  
Vol 83 (4) ◽  
pp. 1313-1326 ◽  
Author(s):  
Giulliari A. S. T. Lira ◽  
Elcida L. Araújo ◽  
Maria Do Carmo Bittencourt-Oliveira ◽  
Ariadne N. Moura
Keyword(s):  
Rainy Season ◽  
Phytoplankton Community ◽  
Dry Season ◽  
Cylindrospermopsis Raciborskii ◽  
Phytoplankton Abundance ◽  
Vertical Variation ◽  
Total Phytoplankton ◽  
Physical And Chemical Variables ◽  
Different Depths ◽  
Physical And Chemical

The present study reports the phytoplankton abundance, dominance and co-existence relationships in the eutrophic Carpina reservoir, Pernambuco, Brazil. Sampling was carried out at six different depths bimonthly at a single reservoir spanning two climatic periods: dry season (January, September, and November 2006) and rainy season (March, May, and July 2006). Density, abundance, dominance, specific diversity and equitability of the community were determined, along with chlorophyll a, and physical and chemical variables of the environment. Eight species were considered abundant, and their densities corresponded to more than 90% of the total phytoplankton community quantified. Cyanobacteria represented more than 80% of this density. Cylindrospermopsis raciborskii was the only dominant taxon in the dry season, and was co-dominant in the rainy season. C. raciborskii, Planktothrix agardhii and Geitlerinema amphibium had the greatest densities and lowest vertical variation coefficients. The statistical analysis indicated relationships with vertical and seasonal variations in the phytoplankton community and the following variables: total dissolved solids, water temperature, electrical conductivity and pH. The changes in the environmental variables were discrete and regulated by the establishment of precipitation however, they were able to promote vertical and seasonal instability in the structure of the phytoplankton community.

scholarly journals Summer aspect of phytoplankton communities in some Montenegrin lakes: Are there changes after more than two decades?

2012 ◽  
Vol 64 (2) ◽  
pp. 745-755
Author(s):  
Jelena Rakocevic
Keyword(s):  
Water Quality ◽  
Sustainable Management ◽  
Aquatic Ecosystems ◽  
Phytoplankton Community ◽  
Management Plan ◽  
Phytoplankton Composition ◽  
Qualitative And Quantitative ◽  
Environmental Monitoring System ◽  
Phytoplankton Communities ◽  
Second Period

Qualitative and quantitative phytoplankton compositions of 10 Montenegrin lakes were investigated in the summer of 2007. The obtained results were compared with a previous study-period that was undertaken two decades ago. In the first period, diatoms numerically dominated the phytoplankton community in all studied lakes, while in the second period, the same was observed only in three of the ten lakes; in other studied lakes the relative contributions of green algae, dinoflagellates and/or cyanobacteria increased, while the contribution of diatoms decreased. The shift observed in phytoplankton composition and diversity in some of the studied lakes indicates an increase in the trophic level over the two decades. The sustainable management plan of the aquatic ecosystems in Montenegro should include the establishment of an environmental monitoring system in order to record any alterations that may take place in water quality.

scholarly journals Spatial-temporal analysis of the diet of a non-native fish in the Santa Cruz Reservoir, Brazilian semi-arid

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Jônnata Fernandes de Oliveira ◽  
Jean Carlos Dantas de Oliveira ◽  
José Luís Costa Novaes ◽  
Antonia Elissandra Freire de Souza ◽  
Marla Melise Oliveira de Sousa ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Abiotic Factors ◽  
Temporal Analysis ◽  
Arid Environment ◽  
Temporal Variations ◽  
Environmental Data ◽  
Animal Origin ◽  
Santa Cruz ◽  
Main Item ◽  
Semi Arid

Abstract Aim The diet of Plagioscion squamosissimus present in the Santa Cruz Reservoir, Rio Grande do Norte, Brazil, was investigated, evaluating the influences of spatial and temporal variations and abiotic factors in the utilization of food resources. Methods The samplings were performed quarterly between February 2011 and November 2014. Of the 525 specimens captured, 375 presented food items in the stomachs. The diet was determined using: (i) Feeding Index (IAi); (ii) and the graphical interpretation of the food strategy through non-metric multidimensional scaling (NMDS) analyzes, the differences in diet being tested from Permutational Multivariate Analyzes of Variance (PERMANOVA). To verify if environmental variables influence the Canonical Correspondence Analyzes (CCA) were used, using the data from the IAi the environmental data, being the significance of the axes tested through Monte Carlo simulations. Results The species feed mainly on items of animal origin, vegetable being a resource ingested accidentally. The diet was composed of shrimp, fish, insect, mollusk and vegetable, the latter rarely found. The shrimp was the main item (92.57%) and the insects (7.24%) accessory items. Spatial and temporal ordering demonstrated that the species didn’t present variation in diet composition, as well as a low association between diet and environmental variables. Conclusion P. squamosissimus is characterized as carcinophagous, due to the predominance of shrimp in its diet, evidencing that the species is adapted to the conditions offered by the Brazilian semi-arid environment.

scholarly journals Assessing temporal and spatial variability of phytoplankton composition in a large reservoir in the Brazilian northeastern region under intense drought conditions

2017 ◽  
Vol 77 (1) ◽  
Author(s):  
Hortência De Souza Barroso ◽  
Janaina A. Santos ◽  
Rozane V. Marins ◽  
Luiz Drude Lacerda
Keyword(s):  
Functional Groups ◽  
Rainy Season ◽  
Temporal Dynamics ◽  
The Other ◽  
Water Transparency ◽  
Phase Iii ◽  
Phytoplankton Composition ◽  
Large Reservoir ◽  
Reservoir Volume ◽  
Total Phytoplankton

The present study was carried out in Castanhão Reservoir, a large aquatic system in the Brazilian semi-arid region that serves multiples uses as water drinking supply and intensive fish-cage aquaculture site. In order to understand the effects of environmental conditions on the spatial and temporal variability of the phytoplankton functional groups (FG) and the main ‘characterizing taxa’, sub-superficial water samples were collected from March 2012 to August 2013, a period distinguished by the continuous drop in reservoir volume due to rainfall shortage. Eighteen functional groups and 102 total phytoplankton taxa were found in the Castanhão reservoir during the study. No significant differences were observed relative to spatial variation of total phytoplankton composition throughout the reservoir (PERMANOVA, P>0.05). On the other hand, according to cluster analysis results, three temporal phases have been identified (Similarity Profile, P<0.05), based on 102 phytoplankton taxa. The ‘characterizing taxa’ was found using the Similarity Percentage procedure (cut-off 90%), being thus defined as those taxa that contributed the most to the similarity within each temporal phase. Nineteen ‘characterizing taxa’ described the Castanhão reservoir, with predominance of those typical of mixing and turbidity conditions. Cyanobacteria dominated through the three temporal phases. According to the redundancy analysis, nutrient availability and water transparency were found to influence the phytoplankton temporal dynamics. The phase I (rainy season) was most represented by Planktolyngbya minor/Pl. limnetica (FG = S1), which reached best performance under strongly decreased phosphate-P concentrations and low water transparency. In phase II (dry season), Romeria victoriae (FG = ?) outcompeted other cyanobacteria probably due the increase in water transparency and decrease in ammonium-N. Finally, in phase III (rainy season) the decrease of water transparency triggered a recovery of shade-adapted cyanobacteria, but at this time mostly represented by Pseudanabaena limnetica (FG = S1). Phase III was also distinctive from the other ones by the highest Nitrate-N and phosphate-P concentrations related to thermocline disruption, which favored an increase in total phytoplankton biomass recorded by the augment of green algae density (FGs = X1, J and F). We concluded that the temporal dynamics of phytoplankton composition was associated to environmental changes in Castanhão Reservoir from 2012 to 2013, which were driven by seasonal climate variation from region (rainy/dry seasons), as well as, by the reduction in reservoir volume that resulted in the disruption of the thermocline, water mixing and an increase in inorganic P and N.

scholarly journals Impact of climate change on the phytoplankton community of the Aglou-Sidi Ifni coastline (Moroccan Atlantic coast)

2020 ◽  
Vol 183 ◽  
pp. 01004
Author(s):  
El mahjoub Gallouli ◽  
Hassan Oulad Ali ◽  
Ahmed Aamiri
Keyword(s):  
Temporal Variability ◽  
Phytoplankton Community ◽  
Atlantic Coast ◽  
Physicochemical Characteristics ◽  
Spatial And Temporal Variability ◽  
Severe Drought ◽  
Phytoplankton Composition ◽  
Annual Cycles ◽  
Objective Monitoring ◽  
Climatic Hazards

The objective of this study is to understand the evolution of the typologies (physicochemical and phytoplankton) in Aglou-Sidi Ifni coastline according to hydrometeorological and climatic hazards. To achieve this objective, monitoring of the phytoplankton community and water physicochemical parameters was conducted at three stations along this coastline and during the winter and fall seasons of two different annual cycles (2014-2016). The first cycle experienced heavy flooding while the second cycle experienced severe drought. This study revealed spatial and temporal variability in phytoplankton composition and the relative abundance of its major groups. Temporal variability may be due to changes in the physicochemical characteristics of water masses as a function of continental inputs and wave intensity, which differ from cycle to cycle and season to another. Whereas the spatial variability would be due to the modification of these physicochemical characteristics from one station to another under the influence of the morphology of the coast in this zone, which curves westwards and carries Cape Aglou at its northern end, thus making the station of Sidi Ifni more exposed to currents than the other two stations which are somewhat sheltered.

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