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

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.

2005 ◽  
Vol 48 (6) ◽  
pp. 983-996 ◽  
Author(s):  
Michael Goulart ◽  
Marcos Callisto

The objectives of this study were to evaluate spatial and seasonal distribution, assemblage structure and substrate associations of mayfly nymphs in five lotic ecosystems in the headwaters of the Doce River and São Francisco River watersheds, Brazil. Samples were taken in 24 sampling stations during rainy and dry seasons in 1998. In total, 7,066 organisms were collected, belonging to 27 genera and 6 families of Ephemeroptera. The dominant taxa were Americabaetis, Paracloeodes, Leptohyphes and Hagenulus. During the rainy period, the São Francisco River watershed showed higher taxonomic richness, diversity and evenness, while in the dry period, the taxonomic richness was higher in Doce River watershed. No significant differences were found in the taxonomic richness, diversity, evenness and density of mayfly assemblages between the two studied sampling periods. The results suggested that the diversity of the mayfly assemblages in tropical headwaters of Serra do Cipó would be probably due to ecosystem and watershed characteristics.


ZooKeys ◽  
2018 ◽  
Vol 777 ◽  
pp. 141-158 ◽  
Author(s):  
Wilson J. E. M. Costa ◽  
Pedro F. Amorim ◽  
José Leonardo O. Mattos

A great diversity of animal species adapted to life in the semi-arid Caatinga of northeastern Brazil, including seasonal killifishes, has been reported in the last three decades. More recently, field and molecular data have shown a high occurrence of cryptic species. The killifish group herein analysed, the Hypsolebiasmagnificus species complex, is endemic to the middle and southern portion of the Caatinga, occupying about 120 km along the floodplains of the middle São Francisco River and some adjacent tributaries. Species of this complex are rare and presently considered threatened with extinction, being uniquely found in pools protected by trees and bushes. Single-locus delimitation methods were used to test species limits of populations displaying different colour patterns along the whole distribution of the complex. All analyses consistently supported the three nominal species and two new, herein described: H.gardneri Costa, sp. n., from the floodplains of the middle São Francisco River and H.hamadryades Costa, sp. n., from the Gorotuba River floodplains. The phylogenetic analysis highly supports H.hamadryades as sister to a clade comprising H.gardneri and H.harmonicus. Our field observations suggest that H.hamadryades is a miniature species. This study indicates that the H.magnificus complex comprises cryptic species apparently endemic to small areas and extremely vulnerable to environmental changes, deserving high concern.


Check List ◽  
2012 ◽  
Vol 8 (5) ◽  
pp. 927 ◽  
Author(s):  
Carlos Eduardo Beserra Nobre ◽  
Clemens Schlindwein

A single male of Heraclides a. astyalus was collected in the Catimbau National Park, Buíque, Pernambuco, located in the semi-arid region of northeastern Brazil. It is the first record for the species in the Caatinga domain and the first record for the subspecies in latitudes above the São Francisco river.


Check List ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 1846 ◽  
Author(s):  
Newton P. U. Barbosa ◽  
Fabiano A. Silva ◽  
Márcia Divina De Oliveira ◽  
Miguel Arcanjo dos Santos Neto ◽  
Marcela David De Carvalho ◽  
...  

Limnoperna fortunei (Dunker, 1857) is a small mytilid native to Southeast Asia. It was introduced in South America in early 1990 and has dispersed from Argentina to central Brazil, and until 2014 has been restricted mainly to the Paraná and Uruguay river basins. The present note reports the occurrence of Limnoperna fortunei for the first time in the São Francisco River basin in northeastern Brazil. The establishment of L. fortunei in these regions will require close attention from the government and also by society.


Check List ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 071 ◽  
Author(s):  
Geraldo J. B. Moura ◽  
Edson V. E. Andrade ◽  
Eliza M. X. Freire

The microhylid frog Stereocyclops incrassatus occurs in humid forests of the eastern coast of Brazil south of the São Francisco River, in the states of Minas Gerais, Espírito Santo and Bahia. The present work reports this species in three Atlantic Rainforest fragments located in states of Alagoas and Pernambuco, northeastern Brazil, thus expanding the known distribution of Stereocyclops incrassatus ca. 1000 km northwards.


2004 ◽  
Vol 64 (4) ◽  
pp. 743-755 ◽  
Author(s):  
M. Callisto ◽  
M. Goulart ◽  
A. O. Medeiros ◽  
P. Moreno ◽  
C. A. Rosa

The main goals of this study were: 1) to evaluate the structure, diversity, and functional trophic group composition of benthic macroinvertebrate communities; 2) to characterize water quality in the headwaters of the Doce river watershed, based on physical, chemical, and biological parameters (benthic macroinvertebrates, fecal coliforms, heterotrophic bacteria, and yeasts); and 3) to contribute to the knowledge of the structure and function of longitudinal gradients in lotic ecosystems in Brazil. A total of 60 benthic macroinvertebrate taxa were identified, the dominant group being the aquatic insects, with 50 families distributed in 8 orders. The dry period presented higher values of taxonomic richness and total density of benthic macroinvertebrates. A decreasing gradient was observed in these variable values from the 3rd order stretch down to the 6th order stretch. The highest Shannon-Wiener diversity values were found in the rainy period in the 3rd order stretches, which presented well-developed riparian forest. Besides the 3rd order stretches, the Pielou evenness index values were also high in the 6th order stretch. The collectors, together with the scrapers, predominated in the benthic macroinvertebrate communities in all river stretches, except in the 2nd, 4th, and 5th order stretches in the rainy period, where communities were dominated by filterers. The shredders and predators presented low densities for all river stretches. All microbiological variables presented low levels. Due to the high counts of heterotrophic bacteria and coliforms, the studied river stretches presented inadequate potability but adequate balneability levels. The results suggest that the structure, diversity, and composition of the benthic macroinvertebrate communities are influenced by the trophic resource availability, seasonality, and sediment heterogeneity. The microbiological results of this study allow inferring that the waters from Serra do Cipó have excellent potential for recreational use and as future sources of water for human consumption.


2017 ◽  
Vol 52 (3) ◽  
pp. 228-238 ◽  
Author(s):  
Daniel Alvares Silveira de Assis ◽  
Vinícius Augusto Dias-Filho ◽  
André Lincoln Barroso Magalhães ◽  
Marcelo Fulgêncio Guedes Brito

2013 ◽  
Vol 17 (2) ◽  
pp. 137-144 ◽  
Author(s):  
Igor P. da Rocha ◽  
Francisco S. R. Holanda ◽  
Renisson N. Araújo Filho ◽  
Ana P. B. Casado ◽  
Arilmara A. Bandeira

The objectives of this paper were to analyze the seasonal distributions of climatic and hydrological variables along the Lower São Francisco River, Northeastern Brazil, between the States of Sergipe and Alagoas, and further, to verify their relationships with the erosion of the right margin in Sergipe State. The investigated area comprises the sedimentary portions of the Lower São Francisco River, located at the Cotinguiba-Pindoba Irrigated Perimeter. Historical records of variables such as rainfall, river streamflow velocity, river discharge, wind velocity and the predominant direction were collected from a climatological station as well as rain and streamflow gauges located in the municipality of Propriá. The rainfall that occurs in the region is considered non-erosive, 96.2% of the rain had intensity less than 25.0 mm h-1. The evolution of erosion is explained by the increase in the outflow in February that peaked at 9,894.50 m³ s-1 and led to increases in the flow velocity. The rainfall regime interacts with the wind that blows predominantly from the eastern direction during the dry season and from the southeastern direction during the rainy season with maximum velocities of 5.5 and 8.0 m s-1, respectively.


2020 ◽  
Vol 12 (21) ◽  
pp. 8982
Author(s):  
Jean Carlos da Silva Galdino ◽  
Marcos Aurélio Vasconcelos Freitas ◽  
Neilton Fidelis da Silva ◽  
Marcio Giannini Pereira ◽  
João Marcelo Dias Ferreira

Semiarid regions are characterized by prolonged droughts and drought regimes. In Brazil, 57% of the northeast region is considered semiarid, with an average annual rainfall of less than 800 mm. This climatic condition imposes the need to conduct public policies and develop infrastructure in order to mitigate drought effects. In this context, the São Francisco River transposition project is an alternative to problems concerning city water supplying and aiming at decreasing socio-economic impacts resulting from water restrictions in this region. On the one hand, the river transposition has the potential to establish a new development cycle in Northeastern Brazil, while, on the other, electricity demands, estimated at 2533 GWh/year from 320 MW of installed capacity, require technological alternatives that ensure the project’s financial sustainability. In this context, this study presents proposals for arrangements concerning electric energy production through photovoltaic systems as an alternative supply for the transposition project. To this end, a study of the region’s photovoltaic solar potential was carried out. Based on the performed assessment, three production arrangement proposals that consider the use of (i) the lateral area and (ii) the transposition channel and (iii) part of the area of some reservoirs belonging to the transposition of São Francisco river. The study point out that the use of this potential for all three studied arrangements is favorable to supply, individually or in a combined form, the electrical energy demanded by the pumping stations installed.


Sign in / Sign up

Export Citation Format

Share Document