scholarly journals Diversity and habitat preference of aquatic insects along the longitudinal gradient of the Macaé River basin, Rio de Janeiro, Brazil

2001 ◽  
Vol 61 (2) ◽  
pp. 249-258 ◽  
Author(s):  
D. F. BAPTISTA ◽  
D. F. BUSS ◽  
L. F. M. DORVILLÉ ◽  
J. L. NESSIMIAN

Diversity and habitat preference of macroinvertebrates were studied in Macaé River basin, Rio de Janeiro State, Brazil, along its longitudinal gradient. We selected stream reaches corresponding to 1st, 2nd, 4th, 5th and 6th orders. A Surber sampler was used to collect four macroinvertebrates samples of each substrate (sand, litter in pool areas, stones, and litter in riffle areas) during the three sampling periods, defined based on the rain regime: April (end of the rainy season), July (dry season), and October (beginning of the rainy season). We identified 46,431 specimens corresponding to 117 taxa. Analysis of diversity numbers (both for family or genus level) indicated that all insect taxonomic orders had higher numbers on 2nd order stream reach, except for Ephemeroptera, on 4th order. However when considering morph-species taxonomic level, the higher diversity number occurred on 4th order stream. The highest richness and diversity numbers were found at the dry season. Considering habitat preference, both litter in pool areas and litter in riffle areas had the highest faunal richness.

2001 ◽  
Vol 61 (2) ◽  
pp. 295-304 ◽  
Author(s):  
D. F. BAPTISTA ◽  
L. F. M. DORVILLÉ ◽  
D. F. BUSS ◽  
J. L. NESSIAMIAN

The distribution and abundance of aquatic insects were studied in the longitudinal gradient of the watershed of Macaé River, a coastal Atlantic Forest river in South-eastern Brazil. Sampling stations were selected in the first, second, fourth, fifth, and sixth orders and sampled in April, July, and October 1995. This represented the end of the rainy season, the dry season, and the beginning of another rainy season, respectively. In each month four samples were collected using a Surber sampler from each of the following substrates: sand, litter deposited in pool areas, litter in riffle areas, and stones. A total of 46,431 specimens of aquatic insects belonging to ten orders were obtained. The data were analyzed by the multivariate methodologies of Correspondence Analysis (CA) and Cluster Analysis (UPGMA) using the similarity index of Morisita, for all three months. Both showed a significant faunal disrupture in the river, which can be divided in two sections: the upper one, from first to fourth orders, and the lower section, including fifth and sixth orders. The same results were obtained with presence-absence matrices, using Jaccard similarity index, showing that the changes are not only due to quantitative differences. A Mantel test was used to compare the assemblage composition temporally and no difference was detected between the three months. Moreover, a Canonical Correspondence Analysis (CCA) was applied to the data to check which of the 14 physical and chemical variables significantly explained macroinvertebrate community variation. The most significant variables were conductivity, CPOM, and pH for the upper stations (1st, 2nd and 4th orders), and alkalinity, FPOM, and HCO3 for the lower stations (5th and 6th orders).


Author(s):  
Zhonghe Zhao ◽  
Gaohuan Liu ◽  
Qingsheng Liu ◽  
Chong Huang ◽  
He Li ◽  
...  

Based on soil sampling data from the dry season and the rainy season, the spatial heterogeneity and spatial pattern of soil nutrients in the Mun River Basin, Thailand, were studied and the seasonal variation in soil nutrients was analyzed using classical statistical methods and geostatistical methods. The soil nutrient content in the Mun Basin showed moderate and strong variations, and the descending order of soil variability was as follows: available phosphorous (AP) > electric conductivity (EC) > soil organic matter (SOM) > total nitrogen (TN) > pH value in the dry season, with AP showing strong variation, and EC > AP > SOM > TN > pH in the rainy season, with EC showing strong variation. Different soil nutrients and different soil properties had different spatial variation characteristics, and their corresponding best-fitting models were also different. Based on the nugget (C0), sill (C0 + C), and range (A), spatial analysis was performed for the soil nutrients, pH, and EC in the dry season and in the rainy season. Analysis based on kriging spatial interpolation data showed that pH, SOM, TN, and EC had convex or concave distributions, whereas AP had a patchy distribution. Terrain, vegetation, and human disturbance are the main factors that contribute to the differences in the soil nutrient pattern of the Mun River Basin.


Author(s):  
José Villarreal Núñez ◽  
Adolfo Santo Pineda ◽  
Jhon Villalaz Pérez ◽  
Iván Ramos Zachrisson

Determine the concentration of heavy metals in water, sediments, and crops within the La Villa river basin, Herrera and Los Santos provinces, republic of Panama. La Villa river Basin, south central of Panama, in the rainy season of 2016 (May to November) and in the dry season of 2017 (December to April). Twenty two sediments and water samples were taken using the systematic method which consists of selecting sampling points at uniform distances and crops in upper, middle and lower basin. The selected sampling was confined to a preferably rectangular area of 10.0 m x 30.0 m, on which the sub-samples were taken with a number of 15 on each grid, at 0.20m depth. For collecting the water samples, a rod with a clean plastic bottle was introduced against the current of the river. The digestion of sediments and crops to determine the concentration of heavy metals (As, Pb, Cr, Ni, Cu, Mn, Zn and Cd) was carried out according to USEPA (25) method (3051A) (SW-846). In the sediments, in the rainy season, Cu (upper and lower basin) and Mn (all levels) values were found above the USEPA Standards. In the dry season, high values of Mn were found in the middle and lower basin, Cr in the upper and lower basin and As in all areas of the basin. In the rainy and dry seasons, high levels of Mn, Zn, Cr, Cd and Pb were found in the waters of the rivers that make up the basin. The main crops at each height of the basin were analyzed, determining high levels of As and Cr in the upper basin, in the middle and lower basin Cr and Cd. It is necessary to monitor the concentration of heavy metals in sediments of La Villa river basin because 90% of the agrochemicals that enter the country is destined for agriculture. Each Panamanian consumes (does not ingest) 3 kg of agrochemicals annually, exceeding six times the amount used in Central America.  Due to their geological origin, these soils are rich in copper, manganese and arsenic, latter being associated with iron oxides and sulfides but there is also great influence of anthropogenic activities, agriculture and industries. Some metals such as lead and arsenic showed low solubility in water but showed high concentration in sediments. Chromium and cadmium present in crops come from water.


Check List ◽  
2013 ◽  
Vol 9 (5) ◽  
pp. 1113 ◽  
Author(s):  
Gabriela Farias Maia ◽  
Roney Emanuel Costa de Paiva ◽  
Aline Barbosa dos Santos ◽  
Henrique Lazzarotto ◽  
Sergio Maia Queiroz Lima

The present study records the first occurrence of the threatened armoured suckermouth catfish Pareiorhaphis garbei (Ihering, 1911) in São João river basin and also its presence in four conservation units in the coastal basins of Serra dos Órgãos mountains, Rio de Janeiro state, Brazil. In São João river basin, P. garbei was only captured in a single locality at 111 m a.s.l., consisting in the lower registered altitude for the species, previously found in high altitudes, usually above 800m.


2014 ◽  
Vol 33 (1) ◽  
pp. 325-337 ◽  
Author(s):  
Fernanda Avelino-Capistrano ◽  
Jorge Luiz Nessimian ◽  
Jacenir Reis Santos-Mallet ◽  
Daniela Maeda Takiya

2018 ◽  
Vol 3 (1) ◽  
pp. 12-18
Author(s):  
Marcelo Wangler de Avila ◽  
Caroline Domingos de Araújo Silva ◽  
Mônica Galeano de Aquino Massera da Hora

The classic definition of the term Hydrometry refers to the study dedicated to the collection and analysis of hydrological variables. The main objective of hydrological studies is to subsidize projects involving water resources, focusing on their use, such as non-water supply, power generation, irrigation, waterways, effluent dilution, sports and tourism. Thus, in order to perform a successful network planning considering multiple demands and to follow different types of occurrence in a given river basin, it is important to design the hydrological monitoring based on all the actions resulting therefrom, on the physiographic characteristics of the basin under study and on the developed activities. In addition, hydrological monitoring should produce accurate information and continuous operation. Therefore, the present study aims to compile guidelines recommended by the National Water Agency, the Brazilian agency responsible for the implementation of the National Water Resources Policy and the National Water Resources Management System. This study also aims to develop a proposal for the planning of the basin's hydrological network of São João River Basin, located in the mesoregion of coastal plains of Rio de Janeiro State. With new technologies support, it focuses on the monitoring of sediment transport, which is fundamental in the decision making regarding future actions of environmental recovery in the basin. Utilizing detailed information, it was possible to verify that insufficient monitoring is occurring in the basin and to produce a set of recommendations for water resources management based on hydrological monitoring.ResumoA definição clássica do termo Hidrometria se refere ao estudo dedicado à coleta e análise de variáveis hidrológicas. O principal objetivo dos estudos hidrológicos é subsidiar projetos que envolvam recursos hídricos, com enfoque em seu uso, como no abastecimento d’água, geração de energia, irrigação, hidrovias, diluição de efluentes, esportes e turismo. Desta forma, para que o planejamento de uma rede tenha êxito em atender as múltiplas demandas ou, em acompanhar os diversos tipos de ocorrência em uma determinada bacia hidrográfica, é importante projetar o monitoramento hidrológico com base em todas as ações nela decorrentes, ou seja, com base tanto nas características fisiográficas da bacia em estudo quanto nas atividades desenvolvidas. Além disso, o monitoramento hidrológico deve produzir informações precisas e com operação de caráter contínuo. Sendo assim, o objetivo do presente estudo está em compilar as diretrizes preconizadas pela Agência Nacional de Águas, órgão responsável pela implementação da Política Nacional de Recursos Hídricos e do Sistema Nacional de Gerenciamento de Recursos Hídricos, e apresentar uma proposta para o planejamento da rede hidrológica da Bacia do Rio São João, localizada na mesoregião das Baixadas Litorâneas do Estado do Rio de Janeiro, com apoio de novas tecnologias, que dê um enfoque especial ao monitoramento do transporte de sedimentos- fundamental na tomada de decisão quanto às ações futuras de recuperação ambiental na bacia. Com o detalhamento destas informações, foi possível verificar a insuficiência do monitoramento na bacia e produzir um conjunto de recomendações que visa a priorizar a gestão dos recursos hídricos a partir de um efetivo monitoramento hidrológico.


CATENA ◽  
2019 ◽  
Vol 182 ◽  
pp. 104103 ◽  
Author(s):  
Chunsheng Wu ◽  
Gaohuan Liu ◽  
Guoxia Ma ◽  
Qingsheng Liu ◽  
Fang Yu ◽  
...  

2018 ◽  
Vol 1 (6) ◽  
pp. 117-126
Author(s):  
Tho Van Le ◽  
Dang Doan Phan ◽  
My Ngoc Diem Tran ◽  
Huy Duc Hoang

This study surveyed and analyzed samples of aquatic insects at 10 pondst Binh Hung Hoa biological system on March and August in 2015. The results recorded 31 species belonging to 24 families, 6 orders, include Coleoptera, Diptera, Odonata, Hemiptera, Ephemeroptera and Trichoptera. In particular, the larvae of theory derdiptera had the best diversity of composition, wise distribution and high density. However, the larvae of t h e order ephemeroptera and order trichoptera had the least diversity and low level of density and distribution at maturation ponds. Among ponds, the diversity and density of aerobic pond and sedimentation pond were high while the maturation ponds were low. The composition of aquatic insects had high similarity in the same function ponds and low similarity in the different function ponds. The species composition diversity and abundance of aquatic insects were the highest in the sedimentation pond and lowest in the other ponds. In the rainy season, the species composition diversity of aquatic insects were higher than those in the dry season.


Author(s):  
I.V.F. Martins ◽  
M.J.S. Pereira ◽  
L. Grisi ◽  
F.B. Scott

The seasonal abundance of lumenal and larval forms of equine strongyles in the State of Rio de Janeiro, Brazil was evaluated. Thirty horses referred to the Federal Rural University of Rio de Janeiro were necropsied and their gastrointestinal tracts were separated into stomach, small intestine, cecum, ventral colon, dorsal colon and rectum. Two aliquots of 5% of the content were collected and examined for the presence of small strongyles and the rest of the content was examined for the presence of large strongyles. The mesenteric artery, liver, pancreas and peritoneum were examined for the presence of strongyle larvae. The mucosa of intestine segments was cut into parts of equal length, and each one was examined by the mural transillumination technique. Higher abundances of larvae of Strongylus equinus (P<0.10) and of adults Strongylus vulgaris (P<0.05) were observed during the dry season. Encysted cyathostome larvae had the highest abundance during the rainy season (P<0.02).


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