Diel variation of limnological parameters in a reservoir in northeastern Brazil (Boa Esperança, Maranhão/Piauí): Rainy period

2007 ◽  
Vol 12 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Paulo Roberto Saraiva Cavalcante ◽  
Maria do Socorro Rodrigues ◽  
Marcel Felipe Sousa Barroso ◽  
Ricardo Barbieri ◽  
Carmen Lúcia Martins Serra ◽  
...  
Keyword(s):  
Northeastern Brazil ◽  
Diel Variation ◽  
Rainy Period ◽  
Limnological Parameters

scholarly journals Spatial and temporal variation of phytoplankton in a tropical eutrophic river

2016 ◽  
Vol 76 (3) ◽  
pp. 600-610 ◽  
Author(s):  
L. M. Santana ◽  
M. E. B. Moraes ◽  
D. M. L. Silva ◽  
C. Ferragut
Keyword(s):  
River Flow ◽  
Light Availability ◽  
Abundant Species ◽  
Northeastern Brazil ◽  
Spatial And Temporal Variation ◽  
Rainy Period ◽  
Lotic Ecosystem ◽  
Phytoplankton Structure ◽  
Accumulated Rainfall ◽  
Eutrophic River

Abstract This study aims to evaluate the environmental factors determining of the changes in phytoplankton structure in spatial (upper, middle and lower course) and seasonal (dry and rainy period) scales in a eutrophic river (Almada River, northeastern Brazil). In the study period, total accumulated rainfall was below of the historic average, resulting in flow reduction, mainly in rainy period. High orthophosphate concentration was found at the sampling sites. Phytoplankton chlorophyll a increased from upstream to downstream. Geitlerinema splendidum (S1) and Chlamydomonas sp. (X2) were the most abundant species in the upper course and several species of diatoms (D), Euglenophyceae (W1, W2) and Chlorophyceae (X1) in the middle and lower course. The functional groups were found to be characteristic of lotic ecosystem, shallow, with low light availability, rich in organic matter and eutrophic environments. We conclude that phytoplankton community structure was sensitive to change of the river flow and nutrient availability in spatial and seasonal scale in a tropical river.

scholarly journals Biodiversity assessment of benthic macroinvertebrates along a reservoir cascade in the lower São Francisco river (northeastern Brazil)

2005 ◽  
Vol 65 (2) ◽  
pp. 229-240 ◽  
Author(s):  
M. Callisto ◽  
M. Goulart ◽  
F. A. R. Barbosa ◽  
O. Rocha
Keyword(s):  
Northeastern Brazil ◽  
Benthic Macroinvertebrate ◽  
Macroinvertebrate Communities ◽  
Negative Consequences ◽  
Cascade System ◽  
System Effect ◽  
Rainy Period ◽  
Sao Francisco River ◽  
São Francisco River ◽  
Significant Difference

In order to verify the cascade-system effect in benthic macroinvertebrate communities, and the implications for policy making and proposals for conservation and sustainable use of the lower portion of São Francisco river basin (Bahia State, Brazil), a three-reservoir cascade system including two stretches downstream were studied during dry (June, 1997) and rainy (March, 1998) periods. The dominant groups found were Mollusca (Melanoides tuberculata), Oligochaeta, and Chironomidae larvae. Low Shannon-Wiener and Pielou index values were found, but with no significant difference between the sampling periods. However, density and taxonomic richness were significantly different (t(0.05; 31) = -2.1945; p < 0.05; e t(0.05; 31) = -3.0600; p < 0.01) between the sampling periods, with a reduction in the number of taxaand macroinvertebrate abundance during the rainy period. An increasing gradient in benthic macroinvertebrate community structures was noted along the reservoir cascade from the first reservoir (Apolônio Sales), followed by a decrease downstream from the third reservoir of the system (Xingó). Despite the negative consequences of rapid proliferation of dams, which have caused widespread loss of freshwater habitats, the reservoir cascade system promoted an increase in benthic macroinvertebrate diversity, due to water-quality improvement along the system.

scholarly journals Influence of river discharge on phytoplankton structure and nutrient concentrations in four tropical semiarid estuaries

2016 ◽  
Vol 64 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Hortência de Sousa Barroso ◽  
Helena Becker ◽  
Vânia Maria Maciel Melo
Keyword(s):  
Urban Areas ◽  
Rainy Season ◽  
River Discharge ◽  
Inorganic Nitrogen ◽  
Dry Season ◽  
Northeastern Brazil ◽  
Nutrient Concentrations ◽  
Freshwater Species ◽  
Rainy Period ◽  
Phytoplankton Structure

Abstract This study evaluated changes in phytoplankton and nutrients after an increase in river discharge in four estuaries of northeastern Brazil. Samples were taken during a markedly freshwater-deprived period (Nov/2010, dry season), and during a rainy season (May/2011). While two estuaries are located in urban areas (Ceará - CE and Cocó - CO), the others are markedly freshwater-deprived (Pacoti - PAC and Pirangi - PIR). Our findings indicate that increased freshwater had opposing effects on estuaries impacted by anthropogenic discharges (CO, CE and PIR) compared with the other, less impacted (PAC). In CO and CE, the freshwater flow during the rainy period had a nutrient diluting effect and controlled phytoplankton blooms. In PIR, only phosphorus and inorganic nitrogen decreased in the rainy season. In contrast, an increase of all nutrients was observed in PAC, and of TN in PIR, followed by an increase in phytoplankton biomass. In the rainy season, eutrophic freshwater species dominated in all the estuaries. In the dry season, blooms of Cryptomonas/Rhodomonas and Synechocystis aquatilis were, respectively, observed in CE and CO. Also in the dry season, PAC and PIR had a predominance of marine species under a condition of hypersalinity. Canonical correspondence analysis suggested the variation observed for salinity, silica, and TN are the main driver of phytoplankton structure.

scholarly journals Benthic Bacillariophyta of the Paripe River estuary in Pernambuco state, Brazil

2007 ◽  
Vol 67 (3) ◽  
pp. 393-401 ◽  
Author(s):  
AN. Moura ◽  
MC. Bittencourt-Oliveira ◽  
EC. Nascimento
Keyword(s):  
New Records ◽  
River Estuary ◽  
Benthic Diatom ◽  
Northeastern Brazil ◽  
Dry Period ◽  
Rainy Period ◽  
Infraspecific Taxa ◽  
Estuary Sediment

The aim of this study was to evaluate the benthic diatom composition from the estuary sediment in the Pernambuco State, based on 32 samples. Samples were collected monthly from September through December 1999 (dry period) and from April through July 2000 (rainy period) during four pre established sampling stations. Results indicated 19 families and 31 specific and infraspecific taxa. Eight new records were founded for Pernambuco State: Auliscus coelatus, Fallacia nummularia, Navicula algida, Plagiograma pulchellum, Terpsinoe americana, Triceratium antideluvianna and Tryblionella coarctata and one, Auliscus punctatus Bailey, in northeastern Brazil.

scholarly journals Drought responses and phenotypic plasticity of Maprounea guianensis populations in humid and dry tropical forests

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Marília Grazielly Mendes dos Santos ◽  
Alexsandro dos Santos Sousa ◽  
Sâmia Paula Santos Neves ◽  
Davi Rodrigo Rossatto ◽  
Lia d’Afonsêca Pedreira de Miranda ◽  
...  
Keyword(s):  
Phenotypic Plasticity ◽  
Water Potential ◽  
Functional Traits ◽  
Environmental Parameters ◽  
Wide Distribution ◽  
Seasonal Rainfall ◽  
Northeastern Brazil ◽  
Plant Responses ◽  
Rainy Period ◽  
Dry Tropical Forests

Abstract The wide distribution of Maprounea guianensis populations in contrasting environments (dry and humid forests) in the Chapada Diamantina, northeastern Brazil, can indicate the phenotypic plasticity of this species in relation to seasonal rainfall, drought regimes, and soil characteristics at different sites. Functional traits were measured in five individuals in each vegetation types. Water potential, succulence, thickness and density leaf, were evaluated during the dry and rainy periods; wood density and the saturated water content of the wood were evaluated in rainy period. Rainfall was monitored monthly for two years. The functional traits and the phenotypic plasticity indices (PPI) were submitted to analysis of variance. Our results demonstrated seasonal and spatial variations in plant functional traits. We found a low capacity for storing water in leaves and woody tissues, associated with soil properties and the seasonal rainfall/drought regimes, conditioning water potential variations that were greatest during the rainy season. Local environmental parameters influenced variations in the functional traits of M. guianensis populations, reflecting phenotypic plasticity. We highlight the connections between drought regimes and plant responses, demonstrating the importance of functional traits associated with water availability (especially water potential). Our study evidences the factors associated with the wide distribution of M. guianensis.

scholarly journals Mollusks associated with the Avicennia schaueriana (Magnoliophyta: Acanthaceae) roots of a hypersaline estuary in northeastern Brazil

2019 ◽  
Vol 31 ◽  
Author(s):  
Ana Priscila Amancio Muniz ◽  
Rafaela Cristina de Souza Duarte ◽  
Ellori Laíse Silva Mota ◽  
Jessica de Oliveira Lima ◽  
Thelma Lúcia Pereira Dias
Keyword(s):  
Water Cycle ◽  
Salinity Gradient ◽  
Northeastern Brazil ◽  
Mangrove Forests ◽  
Estuarine Ecosystem ◽  
Screening Process ◽  
Rainy Period ◽  
Plastic Bags ◽  
Invertebrate Biodiversity ◽  
Avicennia Schaueriana

Abstract Aim Avicennia schaeuriana is one of the six species that composes the mangrove forests of Brazil and form mangrove fringes along waterways. The mangrove-roots of the A. schaeuriana act as one of the microhabitats used by the invertebrate biodiversity of the estuarine ecosystem. The present note aimed to inventory the malacofauna associated with roots of Avicennia schaueriana of the hypersaline and inverse estuary, highlighting variations in abundance and diversity along a salinity gradient and different seasonal periods. Methods Three sampling stations were delineated along the course of the estuary. At each station 3 transects of 10 meters were placed, and for each of them 3 sample points were selected, and at each point 3 samples of roots of A. schaueriana were obtained. A total of 108 samples were stored in plastic bags containing 4% formaldehyde and subsequently passed through a screening process, with identification of the associated specimens with the lowest possible taxonomic level. Results A total of 171 specimens was recorded, belonging to 10 species, 7 families, and 9 genera of the Bivalvia and Gastropoda classes. The abundance of the specimens differed between the seasonal periods analyzed. Conclusions The highest species richness and abundance of organisms in the rainy period allows inferences about the importance of the estuarine water cycle in regulating the biodiversity of these environments. Thus, the importance of the maintenance and protection of the mangrove forests composed of A. schaueriana, as well as the need for more in-depth studies becomes evident.

scholarly journals The influence of seasonality on fish life stages and residence in surf zones: a case of study in a tropical region

2013 ◽  
Vol 13 (3) ◽  
pp. 181-192 ◽  
Author(s):  
Fábio Magno da Silva Santana ◽  
William Severi ◽  
Caroline Vieira Feitosa ◽  
Maria Elisabeth de Araújo
Keyword(s):  
Life Cycle ◽  
Surf Zone ◽  
Mesh Size ◽  
Sandy Beaches ◽  
Northeastern Brazil ◽  
Tropical Region ◽  
Moon Phases ◽  
Rainy Period ◽  
As Species ◽  
Ecological Importance

Resident fishes and their seasonal use of a surf zone were characterized and identified in the Jaguaribe beach, located on the Island of Itamaracá, state of Pernambuco, northeastern Brazil. Monthly towings (March 2006 to February 2007) with a beach seine net (20 m long, 1.5 m high, 5 mm mesh size) in different moon phases and periods of the day (day and night) were conducted. A total of 6,407 specimens, 35 families and 90 species were recorded. Seven species were considered as annual residents (Anchoa tricolor, Anchoviella lepidentostole, Bairdiella ronchus,Larimus breviceps, Lycengraulis grossidens, Polydactylus virginicus and Pomadasys corvinaeformis), three resident throughout the dry season (Conodon nobilis, Lile piquitinga andMenticirrhus americanus) and two resident species in the rainy period (Cathorops spixii and Nicholsina usta). Among these 12 species, concerning their life cycle, three of them (A. tricolor, C. spixii and L. piquitinga) showed only adult individuals, whileB. ronchus, M. americanus and N. usta were the only species represented exclusively by juvenile in both seasons. The surf zone of Jaguaribe beach presents a considerable ecological importance as it encompasses a great diversity of fishes, including species considered rare for this ecosystem, as well as species which are resident annually or seasonally. The distribution pattern of species found in this study shows that the ichthyofauna of the surf zone in Jaguaribe beach is rich, mainly dominated by small-sized individuals including juveniles of several species, with the presence of some species most commonly found in neighboring environments, such as seagrass beds, estuaries and reefs. As an integrated component of interconnected environments in coastal areas of Pernambuco, and owing to its function in the life cycle of coastal fishes, the surf zone of Jaguartibe beach presents an apparently common ecological pattern for tropical sandy beaches.

scholarly journals Spatial modeling of limnological parameters in a solar saltwork of northeastern Brazil

2015 ◽  
Vol 27 (1) ◽  
pp. 105-117 ◽  
Author(s):  
Diógenes Félix da Silva Costa ◽  
José Etham de Lucena Barbosa ◽  
Amadeu Mortágua Velho de Maia Soares ◽  
Ana Isabel Lillebø ◽  
Renato de Medeiros Rocha
Keyword(s):  
Inorganic Nitrogen ◽  
Northeastern Brazil ◽  
Spatial Gradient ◽  
Salt Ponds ◽  
Gis Technology ◽  
Heterogeneous Distribution ◽  
Evaporation Ponds ◽  
Salt Production ◽  
Solar Saltworks ◽  
Limnological Parameters

AimIn this research, we aimed to model limnological parameters in the Salina Unidos (Macau-Brazil) using GIS technology. We hypothesized that in solar saltworks, the geochemical characteristics of the brines (i.e. the strong solution of salts) vary considerably through the salt ponds circuit, in which drastic changes can damage the entire salt production.MethodsGeochemical parameters were monitored in seven sampling points distributed along the salt ponds circuit, during a complete cycle of salt production, i.e., from January to December 2007. The open source software Spring 5.1.6 was used to build, store, analyze and model the spatial distribution of the parameters.ResultsWe identified a spatial gradient of the salinity and temperature, with values increasing from evaporation ponds to concentration ponds, showing a relationship with the salt production. The parameters, depth, dissolved oxygen concentrations and total dissolved reactive phosphorus showed a decrease from the evaporation ponds towards the concentration ponds. Among the dissolved inorganic nitrogen forms analyzed (NH3-, NO2- and NO3-), nitrate was the predominant, namely in the concentration ponds, where it reached the highest concentrations. The concentration of chlorophyll awas higher in the initial and intermediate evaporation ponds, showing a distinct dynamics of in relation to other environmental variables.ConclusionsThe increased concentration of the analyzed limnological parameters, from the evaporation ponds towards the concentration ponds, evidenced a heterogeneous distribution varying significantly with season. The geochemical spatialization of brine, as illustrated by GIS approach, is very important for the conservation of these environments because this spatial heterogeneity can provide a high diversity of habitat types. This spatial analysis proved to be a practical tool for an adequate management of solar saltworks considering the environmental (ecosystem) and the socio-economic aspects.

Limnological characteristics, community metabolism and management strategies of a coastal sinkhole in Cuba (Cenote Jennifer)

2020 ◽  
Vol 56 ◽  
pp. 24
Author(s):  
Roberto González-De Zayas ◽  
Liosban Lantigua Ponce de León ◽  
Liezel Guerra Rodríguez ◽  
Felipe Matos Pupo ◽  
Leslie Hernández-Fernández
Keyword(s):  
Hydrogen Sulfide ◽  
Primary Productivity ◽  
Major Ions ◽  
Saline Water ◽  
Management Strategies ◽  
Tourist Destination ◽  
Community Metabolism ◽  
Morphological Studies ◽  
Made In ◽  
Limnological Parameters

The Cenote Jennifer is an important and unique aquatic sinkhole in Cayo Coco (Jardines del Rey Tourist Destination) that has brackish to saline water. Two samplings were made in 1998 and 2009, and 4 metabolism community experiments in 2009. Some limnological parameters were measured in both samplings (temperature, salinity, pH, dissolved oxygen major ions, hydrogen sulfide, nutrients and others). Community metabolism was measured through incubated oxygen concentration in clear and dark oxygen bottles. Results showed that the sinkhole limnology depends on rainfall and light incidence year, with some stratification episodes, due to halocline or oxycline presence, rather than thermocline. The sinkhole water was oligotrophic (total nitrogen of 41.5 ± 22.2 μmol l−1 and total phosphorus of 0.3 ± 0.2 μmol l−1) and with low productivity (gross primary productivity of 63.0 mg C m−2 d−1). Anoxia and hypoxia were present at the bottom with higher levels of hydrogen sulfide, lower pH and restricted influence of the adjacent sea (2 km away). To protect the Cenote Jennifer, tourist exploitation should be avoided and more resources to ecological and morphological studies should be allocated, and eventually use this aquatic system only for specialized diving. For conservation purposes, illegal garbage disposal in the surrounding forest should end.

Chemical evaluation and microbiological assays of medicinal plants used in traditional communities in northeastern Brazil

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
JP Ferreira-Neto ◽  
RJSA Padilha ◽  
ERB Santana ◽  
DN Gomes ◽  
KXFR Sena ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Northeastern Brazil ◽  
Chemical Evaluation ◽  
Microbiological Assays ◽  
Traditional Communities
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