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 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 Effects on circulation and water renewal due to the variations in the river flow and the wind in a Brazilian estuary lagoon complex

2021 ◽  
Vol 16 (2) ◽  
pp. 1
Author(s):  
Cynara De Lourdes da Nóbrega Cunha ◽  
Ada Cristina Scudelari ◽  
Danilo De Oliveira Sant'Ana ◽  
Teresa Elane Bezerra Luz ◽  
Mariana Kummer da Rocha Pinheiro
Keyword(s):  
Free Surface ◽  
River Flow ◽  
Transport Model ◽  
Northeastern Brazil ◽  
Spatial And Temporal Variation ◽  
Open Boundary ◽  
Channel System ◽  
Narrow Channels ◽  
Water Renewal ◽  
Wind Influence

The Mundaú-Manguaba Estuary Lagoon Complex is located on the coast of Alagoas state in Northeastern Brazil, and consists of two shallow lagoons, Mundaú and Manguaba, that form a system of choked lagoons which are connected to the Atlantic Ocean by a series of narrow channels with a single outlet which dynamically alters its position. This study uses the Hydrodynamic Environmental System, SisBaHiA® to investigate how variations in river discharge and wind influence hydrodynamic circulation, water renewal, salinity and temperature in the lagoons. The free surface positions, obtained by model, were compared with the free surface positions measured at two points of the complex, showing good agreement. The analyses were carried out for dry and wet seasons and extreme events with very high freshwater discharge. The channel system of the lagoons is an efficient filter in reducing tidal variability inside the lagoons. The tidal ranges in the Manguaba and Mundaú Lagoons are 90% and 80% lower, respectively, as compared with the values in the open boundary. The residence time calculated varied between 11 and 365 days and between 2 and 180 days for the Manguaba and Mundaú Lagoons, respectively, making it possible to identify possible stagnation areas. The results from the salt and heat transport model show a prolonged period with low salt concentrations and slow salinity recovery after the rainy season; the water temperature in the lagoons shows little spatial and temporal variation.

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 Nocturnal and diurnal pollination in Copaifera coriacea, a dominant species in sand dunes of the Middle São Francisco River Basin, Northeastern Brazil

2021 ◽  
Vol 154 (2) ◽  
pp. 207-216
Author(s):  
Isys Mascarenhas Souza ◽  
Frederic Mendes Hughes ◽  
Ligia Silveira Funch ◽  
Luciano Paganucci de Queiroz
Keyword(s):  
Uv Light ◽  
Pollen Viability ◽  
Sand Dunes ◽  
Abundant Species ◽  
Pollen Tubes ◽  
Northeastern Brazil ◽  
Stigma Receptivity ◽  
Flower Opening ◽  
Pollination System ◽  
Floral Visitors

Background and aims – Copaifera coriacea, a species in the resin-producing clade Detarioideae (Leguminosae), is an endemic and abundant species found in sand dunes in Brazilian Caatinga domain vegetation – a Quaternary paleodesert. We investigated floral traits and aspects of pollination biology, focusing on the pollination system of C. coriacea. Material and methods – Anthesis duration, stigma receptivity, pollen viability, nectar concentration, and the presence of osmophores and pigments reflecting UV light were assessed. Floral visitors were classified as potential pollinators, occasional pollinators or thieves, based on the time and foraging behaviour and resource collected. Pollination effectiveness were assessed for potential pollinators by the detection of pollen tubes on the stigma or stylar canal by epifluorescence microscopy.Key results – The species has white and small flowers, with anthesis beginning in the dark (ca 00:30) and the flowers are completely opened approximately 3 h later, when a sweet odour is perceptible. The onset of stigma receptivity and pollen grain viability occurs only after the completion of flower opening, and a concentrated nectar is available during the day. The presence of pollen tubes confirmed the efficiency of the main insects in the transfer of pollen. Conclusion – Our result demonstrates that C. coriacea has a generalist pollination system mediated mainly by two distinct guilds of insect pollinators: moths (nocturnal, searching for nectar) and bees (diurnal, pollen collectors). This finding can provide more information about diversification in the genus Copaifera.

scholarly journals Fish diversity of floodplain lakes on the lower stretch of the Solimões River

2004 ◽  
Vol 64 (3a) ◽  
pp. 501-510 ◽  
Author(s):  
F. K. Siqueira-Souza ◽  
C. E. C. Freitas
Keyword(s):  
Species Richness ◽  
Fish Community ◽  
River Flow ◽  
Abundant Species ◽  
Floodplain Lakes ◽  
Fish Diversity ◽  
The Town ◽  
Solimões River

The fish community of the Solimões floodplain lakes was studied by bimonthly samples taken from May 2001 to April 2002. These were carried out at lakes Maracá (03º51'33"S, 62º35'08,6"W), Samaúma (03º50'42,1"S, 61º39'49,3"W), and Sumaúma and Sacambú (03º17'11,6"S and 60º04'31,4"W), located between the town of Coari and the confluence of the Solimões and Negro rivers. Collections were done with 15 gillnets of standardized dimensions with several mesh sizes. We collected 1,313 animals distributed in 77 species, belonging to 55 genera of 20 families and 5 orders. Characiformes was the most abundant Order, with a larger number of representatives in the Serrasalmidae and Curimatidae. The most abundant species in the samplings were Psectrogaster rutiloides (132 individuals), Pigocentrus nattereri (115 individuals), and Serrasalmus elongatus (109 individuals). Lakes Samaúma, Sacambú, and Sumaúma were adjusted to logarithmic and lognormal series. The diversity exhibited an inverse gradient to the river flow, showing the highest diversity at Lake Sumaúma, followed by Samaúma, Sacambú, and Maracá. Species richness estimated through the jackknife technique ranged from 78 to 107 species.

scholarly journals Inventory of mollusks from the estuary of the Paraíba River in northeastern Brazil

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Silvio Felipe Barbosa Lima ◽  
◽  
Rudá Amorim Lucena ◽  
Galdênia Menezes Santos ◽  
José Weverton Souza ◽  
...  
Keyword(s):  
Species Richness ◽  
Environmental Monitoring ◽  
Local Population ◽  
Abundant Species ◽  
Coastal Ecosystems ◽  
Economic Importance ◽  
Northeastern Brazil ◽  
Marine Mollusks ◽  
The Family

Abstract: Coastal ecosystems of northeastern Brazil have important biodiversity with regard to marine mollusks, which are insufficiently studied. Here we provide an inventory of mollusks from two sites in the estuary of the Paraíba River. Mollusks were collected in 2014 and 2016 on the coast and sandbanks located on the properties of Treze de Maio and Costinha de Santo Antônio. The malacofaunal survey identified 12 families, 20 genera and 21 species of bivalves, 17 families, 19 genera and 20 species of gastropods and one species of cephalopod. Bivalves of the family Veneridae Rafinesque, 1815 were the most representative, with a total of five species. Gastropods of the family Littorinidae Children, 1834 had the greatest species richness. The most abundant species were: Neritina virginea (Linnaeus, 1758), Brachidontes exustus (Linnaeus, 1758), Crassostrea brasiliana (Lamarck, 1819), Cerithium atratum (Born, 1778), Anomalocardia brasiliana (Gmelin, 1791), Parvanachis obesa (C. B. Adams, 1845), Phrontis polygonata (Lamarck, 1822), Littoraria angulifera (Lamarck, 1822), L. flava (King, 1832), Tagelus plebeius (Lightfoot, 1786), Echinolittorina lineolata (d'Orbigny, 1840) and Iphigenia brasiliensis (Lamarck, 1818). The results show that the study area has considerable species richness of Mollusca, requiring environmental monitoring in the region mainly due to the economic importance of some species to the local population.

scholarly journals Diversity of scorpions (Chelicerata: Arachnida) in the Atlantic Forest in Pernambuco, northeastern Brazil

Check List ◽  
2014 ◽  
Vol 10 (6) ◽  
pp. 1331 ◽  
Author(s):  
André Felipe de Araujo Lira ◽  
Cleide Maria Ribeiro de Albuquerque
Keyword(s):  
Atlantic Forest ◽  
Abundant Species ◽  
Northeastern Brazil ◽  
Forest Fragments ◽  
Moon Phase ◽  
The Family ◽  
New Moon ◽  
Important Center ◽  
Uv Lamps ◽  
Northeastern Atlantic

This study was conducted to measure the biodiversity of scorpion species in the remnants of the Brazilian northeastern Atlantic Forest, an important center of biodiversity and endemism. Collections were performed in twelve forest fragments in Sirinhaém municipality, Pernambuco State, through active searches at night by using UV lamps between 19:00h and 21:00h during the new moon phase in December 2012 and January 2013. A total of 1,125 specimens from two genera and five species were collected: Tityus pusillus Pocock, 1893; Ananteris mauryi Lourenço, 1982; Tityus brazilae Eickstedt & Lourenço, 1984; Tityus neglectus Mello-Leitão, 1932; and Tityus stigmurus (Thorell, 1876), all belonging to the family Buthidae C.L. Koch, 1837. The most abundant species was T. pusillus (90.7%), followed by A. mauryi (7.1%). Tityus brazilae, T. neglectus, and T. stigmurus together represented less than 3% of the individuals sampled.

Effects of seasonality on drosophilids (Insecta, Diptera) in the northern part of the Atlantic Forest, Brazil

2017 ◽  
Vol 107 (5) ◽  
pp. 634-644 ◽  
Author(s):  
R.D. Coutinho-Silva ◽  
M.A. Montes ◽  
G.F. Oliveira ◽  
F.G. de Carvalho-Neto ◽  
C. Rohde ◽  
...  
Keyword(s):  
Exotic Species ◽  
Atlantic Forest ◽  
Seasonal Pattern ◽  
Abundant Species ◽  
Neotropical Region ◽  
Dry Season ◽  
Opposite Pattern ◽  
Tropical Regions ◽  
Rainy Period ◽  
Northern Atlantic

AbstractSeasonality is an important aspect associated with population dynamic and structure of tropical insect assemblages. This study evaluated the effects of seasonality on abundance, richness, diversity and composition of an insect group, drosophilids, including species native to the Neotropical region and exotic ones. Three preserved fragments of the northern Atlantic Forest were surveyed, where temperatures are above 20 °C throughout the year and rainfall regimes define two seasons (dry and rainy). As opposed to other studies about arthropods in tropical regions, we observed that abundance of drosophilids was significantly higher in the dry season, possibly due to biological aspects and the colonization strategy adopted by the exotic species in these environments. Contrarily to abundance, we did not observe a seasonal pattern for richness. As for other parts of the Atlantic Forest, the most representative Neotropical species (Drosophila willistoni, D. sturtevanti, D. paulistorum and D. prosaltans) were significantly more abundant in the rainy season. Among the most abundant exotic species, D. malerkotliana, Zaprionus indianus and Scaptodrosophila latifasciaeformis were more importantly represented the dry season, while D. simulans was more abundant in the rainy period. The seasonality patterns exhibited by the most abundant species were compared to findings published in other studies. Our results indicate that exotic species were significantly more abundant in the dry season, while native ones exhibited an opposite pattern.

scholarly journals Phlebotomines in an area endemic for American cutaneous leishmaniasis in northeastern coast of Brazil

2017 ◽  
Vol 26 (3) ◽  
pp. 280-284 ◽  
Author(s):  
Ana Patricia Oliveira da Silva ◽  
Débora Elienai de Oliveira Miranda ◽  
Marcos Antônio Bezerra Santos ◽  
Neurisvan Ramos Guerra ◽  
Silvia Rafaelli Marques ◽  
...  
Keyword(s):  
Disease Control ◽  
Cutaneous Leishmaniasis ◽  
Abundant Species ◽  
Risk Of Infection ◽  
Light Traps ◽  
Rainy Period ◽  
Worldwide Distribution ◽  
American Cutaneous Leishmaniasis ◽  
Leishmania Spp ◽  
Northeastern Coast

Abstract Phlebotomines have worldwide distribution with many species present in Brazil, including the northeastern region, where the fauna is very diverse. The aim of this study was to identify the sandfly fauna in an area endemic for American cutaneous leishmaniasis (ACL) in the state of Pernambuco. Sandflies were caught on three consecutive nights every month from October 2015 to September 2016, from 5 pm to 5 am, using seven light traps of Centers for Disease Control (CDC) type. Females were identified and used for molecular Leishmania detection. A total of 2,174 specimens belonging to ten species were collected: Lutzomyia choti (88.2%; 1,917/2,174) was the most abundant species, followed by Lutzomyia whitmani (8.1%; 176/2,174) and Lutzomyia sordellii (1.5%; 33/2,174). The majority of the specimens were collected in peridomestic areas (64.1%; 1,394/2,174) and during the rainy period. All the samples examined were negative for Leishmania spp. The presence of Lutzomyia whitmani indoors and in peridomestic areas indicates that the inhabitants of this area are exposed to the risk of infection by the parasites responsible for ACL.

scholarly journals Nongeniculate coralline red algae (Rhodophyta: Corallinales) in coral reefs from Northeastern Brazil and a description of Neogoniolithon atlanticum sp. nov.

Phytotaxa ◽  
2014 ◽  
Vol 190 (1) ◽  
pp. 277 ◽  
Author(s):  
FREDERICO T. S. TÂMEGA ◽  
Rafael Riosmena-Rodriguez ◽  
RODRIGO MARIATH ◽  
Marcia Figueiredo
Keyword(s):  
Coral Reefs ◽  
Critical Evaluation ◽  
Taxonomic Status ◽  
First Record ◽  
Abundant Species ◽  
Northeastern Brazil ◽  
Type Material ◽  
Coralline Algae ◽  
Coralline Red Algae ◽  
Western Atlantic

A taxonomic reassessment of coralline algae (Corallinales, Rhodophyta) associated with reef environments in the Abrolhos Bank, northeastern Brazil, was developed based on extensive historical samples dating from 1999–2009 and a critical evaluation of type material. Our goal was to update the taxonomic status of the main nongeniculate coral reef-forming species. Our results show that four species are the main contributors to the living cover of coral reefs in the Abrolhos Bank: Lithophyllum stictaeforme, Neogoniolithon atlanticum sp. nov., Porolithon pachydermum and Spongites fructiculosus. Comparison of the type material to modern collections has shown that Lithophyllum congestum is a heterotypic synonym of L. stictaeforme. However, L. stictaeforme and P. pachydermum were the most abundant species at the studied sites, a finding consistent with other coral reefs in the region. This is the first record of S. fructiculosus in the southwestern Atlantic. This review provides the baseline data needed for the monitoring and management of the southernmost limits of coral reefs in the western Atlantic Ocean.

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