Repositório RCAAP

Universidade Federal de Minas Gerais

Three experiments were carried out at the Aquaculture Section of the Center for the Technological Development of Agribusiness in Pindamonhangaba, Sao Paulo, Brazil, whose objective was to test the use of low-volume cages in populated or not populated ponds, aiming for a better utilization of the flooded area, as well as to assess the productivity of tilapia strains. The experiments were brought to an end when the units from at least one treatment reached mean weight value of 500g (commercial size). The first experiment was carried out from March to July 2000 (fall/winter). Three cages populated with Thai tilapia (Oreochromis niloticus) male juveniles, and three cages populated with red tilapia Oreochromis urolepis hornorum x Oreochromis mossambicus) male juveniles, at densities of 200, 250 and 300 fish/m³ were placed in each pond. After 126 days of culture, final mean weight and mean biomass were the double for the Thai tilapia than for the red one at the studied densities. The red tilapia did not reach commercial size at any of the densities. Feed conversion ranged from 1.24 to 1.50:1 among the densities, and survival rate was over 90% for all the treatments. The studied abiotic variables, with the exception of temperature, exhibited suitable values for the culture of tilapia. The objective of the second experiment, carried out from February to April 2001 (summer/fall), was to assess the productivity of the Thai tilapia in cages (intensive culture) placed in populated (semiintensive culture) or not populated ponds. Six cages with Thai tilapia males, at densities of 200, 250 and 300 fish/m³ were placed in the two ponds (V1 and V2). V2 was also populated with 4800 free male units of the same species. After 76 days of culture, the tilapia from the cages in P1 reached mean weight higher than 500g. In V2, only the units kept at the density of 200 fish/m³ reached 500g.Apparent feed conversion was around 1.0:1 for the confined fish and 1.3:1 for the free ones; survival rate was over 90% for all the treatments. The net yield in V2 was 2.7 times higher than in V1.The third experiment, carried out between February and June 2002 (summer/fall), examined the productivity of the Thai tilapia, as well as the effect of the amount of cages on the pond carrying capacity. Two ponds (V1 and V2) were populated with 4800 Thai tilapia male units. Six cages with 250 units each were placed in V1, and twelve (also with 250 units each) were placed in V2. After 60 days, the mortality rate in V2 was 35% for the confined population and 15% for the free fish, due to a sharp decrease in the dissolved oxygen concentration, suggesting that the pond had reached its maximum carrying capacity. At the end of the experiment, after 120 days of culture, only the units from the cages placed in V1 reached commercial size.

With the objective to verify the distribution and the taxonomic structure of the benthic macroinvertebrates fauna of water systems (reservoir, fisheries and channels) of the CEPTA/IBAMA (Pirassununga, SP), a study with two types of methodologies was carried out. The samples of the sediment in the reservoir had been carried out with the Ekman-Birge grab, and in the fisheries and the channels with artificial substrate. The assemblages of benthic macroinvertebrates had been analyzed taxonomic and structurally. The larvae of Chironomidae (Diptera) were the main organisms in all the environments. The predominance of Procladius sp. and Djalmabatista pulcher was observed in the two reservoirs. The spatial analysis of the taxa distribution in the depths, pointed out with to major variety of taxa in the less depth regions (< 2m) in the Represa Velha, in contrast of the Represa Nova. At the same time, the average densities of the organisms had been opposing in the two reservoirs, presenting respectively major and lesser values in the intermediate depths (>2<3m). Temporaly, major abundance of macroinvertebrates at the dry season was observed, where major number of individuals occurred, represented mainly for the Procladius sp. and D. pulcher. In the faunistic analysis with artificial substrate, Goeldichironomus maculatus was dominant. There was taxonomic similarity between the assemblages in the artificial substrates in the reservoirs, fisheries and channels. The cluster analysis between the sampling methods, clustering the fauna of the baskets with the artificial substrate in the two reservoirs, and the fauna collected with the Ekman-Birge grab. This result points out with respect to the problematic use of artificial substrate use as a tool to characterize the fauna of a system.

The present work analyzed the population dynamics of Callinectes danae Smith, 1869 and Callinectes ornatus Ordway, 1863 (Crustacea, Portunidae) captured as by-catch from pink-shrimp trawlings at Guanabara Bay. Three aspects were approached: reproduction, growth and mortality. The reproductive analysis pointed out four stages of gonadal maturation for both species, corroborated by histological procedures and classified as: stage I - immature, stage II - developing, stage III - ripe and stage IV - spent. The presence of oocytes I and oocytes II in the stages ripe and spent confirmed the multiple spawning hypotheses for the species. The size at first gonadal maturity was 85.2 mm and 67.2 mm respectively for C. danae and C. ornatus. The continuous reproduction pattern was observed, however with seasonal and alternated reproductive picks in the bay. While C. danae presented reproductive picks in the autumn and in the winter, C. ornatus presented an apparent reproductive pick in the summer and probably another one in the spring. The sexual proportions diverged in C. danae significantly in females favor (3.0:1). However, to C. ornatus the proportions diverged with prevalence of males (1.2:1). This pattern indicated that possibly the females of C. danae return to the estuary after the spawning, while the ovigerous females of C. ornatus migrate to adjacent coastal areas around the bay. The growth analysis was based on indirect methods of size-frequency distributions. The growth parameters were estimated according von Bertalanffy s (1938) growth function and longevity according D Incao & Fonseca (1999). The L&#8734; value corresponded to the largest individual captured for each species and for each sex. For C. danae the growth x parameters were the following ones: females - L&#8734; = 113 mm, k = 0.005088387 and longevity = 2.48 years; males - L&#8734; = 120 mm, k = 0.005550913 and longevity = 2.27 years. For C. ornatus the growth parameters were: males - L&#8734; = 94 mm, k = 0.005372092 and longevity = 2.34 years; females - L&#8734; = 110 mm, k = 0.00594237 and longevity = 2.25 years. The instantaneous rate of total losses (Z ) from Ricker's (1975) catch curve associated to the natural mortality from Taylor's (1959) method showed high values of (F) mainly on the females of both species. However, for the females of C. ornatus the migration actuated in an intense way increasing the instantaneous rate of total losses. The stocks explotation rates were also high. Except for the males of C. danae, all the others were above the acceptable exploration. Besides that, 50.7% and 87.2% of females respectively from C. danae and C. ornatus were captured below the mean size at gonadal maturation. The diagnostic above suggests more effective management actions on these natural resources, not only by the responsible governmental organs, but also, by all the actors involved in the process.

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Este trabalho teve como questão central as contribuições que a Educação Ambiental e a abordagem ecológica das águas poderiam apresentar para a gestão dos ecossistemas aquáticos, com ênfase no meio ambiente rural. Para isto, foi realizado um estudo de caso com uma comunidade rural inserida na bacia do alto rio Pardo, no Município de São José do Rio Pardo, SP. A caracterização do contexto estudado e dos participantes desta pesquisa revelou a perda da biodiversidade local, bem como transformações negativas nos ecossistemas aquáticos e terrestres, associadas às praticas de manejo das unidades produtivas. Algumas características do sistema de produção e comercialização dos produtos cultivados se mostraram incompatíveis com o desenvolvimento de uma agricultura sustentável, uma vez que, geram grandes impactos negativos no ambiente natural, ao mesmo tempo em que não oferecem retornos econômicos satisfatórios, no contexto analisado. Considerando esses aspectos da realidade local, foi desenvolvido e implementado, de forma participativa, uma intervenção educativa com os participantes da comunidade rural, bem como com uma comunidade escolar. Esta intervenção objetivou a construção conjunta de conhecimentos para a gestão otimizada e contextualizada da água no ambiente rural. Os resultados dessas intervenções mostraram que a abordagem ecológica da água e a Educação Ambiental podem contribuir nos processos de gestão dos ecossistemas aquáticos visando a minimização dos impactos ambientais deste setor produtivo, com contribuições para o desenvolvimento de uma agricultura sustentável. Estas contribuições podem se dar através da participação das comunidades na busca de alternativas para a minimização dos impactos das práticas produtivas sobre os ecossistemas, considerando-se a importância das águas tanto para os seres humanos, como para os demais seres vivos. A participação dos usuários da água no estabelecimento de mecanismos de gestão possibilita o desenvolvimento de instrumentos condizentes com as realidades consideradas. Desta forma, a viabilidade ambiental da implementação de tais instrumentos pode ser considerada, com abordagem sobre os aspectos biológicos, históricos, culturais, sócio-econômicos, dentre outros, que compõem o ambiente.

The present work evaluated a proposed methodology to analyze the aspects that involve the dynamics of the agroecosystem valuing the interactions among dimensions: ecological, social and agroecological practice, the last one being developed by farmer, aiming to identify at what stage of agroecological transition is inserted, valuing the aspects in the quantitative and qualitative way involving the processes, and that be useful as a management tool, based on the principle of multiple functions and management. The indicators analyzed proved feasible because there was the possibility of analyzing and comparing the rates obtained serving as a management tool for the agroecosystem. From the fifteen analyzed agroecosystems, 6,66% were classified on agroecological transition consolidated stage, 13,33% of agroecosystems were classified on agroecological transition consolidation stage on as the field protocol, 46,66% on agroecological transition capacitance stage and 33,33% were classfied on agroecological transition initial stage. None of the analyzed agrecosystems were classified on conventional stage. As a conclusion on obtained data the field protocol shows be efficient tool of management and agroecosystems analysis.

Release of extracellular polysaccharides can occur from healthy and active cells and has been demonstrated to be an important carbon source for bacteria. In eutrophic environments where large blooms are formed by efficient extracellular polysaccharide producers such as Microcystis aeruginosa and Anabaena spiroides, these organic materials (high molecular weight extracellular polysaccharides) may support planktonic bacterial growth. The aim of this study was to evaluate the extracellular glycolytic enzyme activity during a seasonal cycle and a possible regulation of the corresponding enzymes in response to variation of polysaccharides in Barra Bonita Reservoir. The majority of enzymes exhibited a significant decrease during the dry season (April to September). The content of total dissolved carbohydrates varied from 0.5 to 6.83 mg L-1 and was mainly (92%) constituted by polysaccharides. Phytoplanktonic community showed a marked succession with cyanobacteria typically dominating during the rainy season (Microcystis sp, Microcystis aeruginosa and Anabaena spiroides), whereas diatoms (mostly Aulacoseira granulata) and cryptophytes (Cryptomonas sp) were dominant through the dry season. Four algal blooms were observed during the experimental period, and after each bloom the release of combined carbohydrates was followed by high enzymatic activities, thus the production of extracellular enzymes for microheterotrophic microorganisms was related to the influx of polymeric organic substances. Even the monosaccharides composition of reservoir samples after each bloom roughly revealed the extracellular polysaccharide composition of dominant phytoplanktonic population. Experiments of polysaccharide degradation from Barra Bonita Reservoir and produced by dominant phytoplanktonic organisms (A. granulata e M. aeruginosa) assayed in laboratory conditions had confirmed the interpretation of data measured in field.

In order to evaluate the physical, chemical, biological and ecotoxicological parameters of Monjolinho River system (in laboratory and in situ), water and sediment samples (from the river and from eight of its tributaries) we obtained in july/03, October/03, January/04 and April/04. Juveniles and adult individuals of Danio rerio and Poecilia reticulata were used in the ecotoxicological studies. Mortality, juvenile biometry, and deletery effects observed on the gills tissue were considered in the tests. The limnological data revealed the higher concentrations of heavy metals and organochlorides in the dry season, being over the limits established for aquatic organisms protection. The concentrations of zinc and heptachlore found in the sediments of the last study sites resulted in deletery effects. The higher concentrations of the analyzed parameters were found in the study sites UFSCar, Confluência and Córrego Tijuco, probably due to the higher concentrations of clay and silt found in these areas. The partially chronic tests performed using samples obtained from the natural environment revealed significant toxicity for at least one fish species and one parameter. Tests in situ showed more drastic effects, especially in July/03. P. reticulata was more vulnerable when compared to D. rerio in all of the analyses, especially considering the juvenile stages. Two contaminants were used in the laboratory ecotoxicological analyzes, using D. rerio juveniles as a test organism. Cadmium showed a CL(I)50, 96h, of 1894,73µg/L. In the tests of static partial chronic toxicity, the chronic value obtained was 189,73µg/L, for both survival and growth, indicating that in the same concentration, the effects on the survival and biometry were similar. Gills morphological alterations increased with the increasing concentrations: 0.6 µg/L, 6 µg/L, 60 µg/L and 600 µg/L, being the fusion of the secondary lamellaes observed in the last concentration. Regarding to the endossulfan sulphate, the semi-static CL(I)50, 96h, was 7.24 µg/L and the chronic value, considering survival rates, was 0.948 µg/L. Histological effects were observed in all of the concentrations (0.03 µg/L, 0,3 µg/L and 3 µg/L), being the hyperplasia and secondary lamellae fusions more drastic in the last concentration. The toxicity tests, as well as the limnological analyses, showed that the Monjolinho system in highly disturbed, with inadequate conditions for the conservation of the aquatic organisms and may represent risks for the human health.

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The Itajaí river estuary, SC, is located in the final portion of Itajaí river watershed, which has a total area of about 15,500 km2. The terminal region of this watershed is characterized by the presence of important cities such as Blumenau and Itajaí. Agriculture is also important, specially irrigated rice culture. The aim of this study was to evaluate the spatial-temporal variability of water quality and the nutrient transport and transformation processes in the estuary. A weekly monitoring was carried out from october/2003 to december/2004, along seven estuarine sampling stations, one station in the Itajaí-Mirim river (the main tributary) and one reference station located in a undisturbed area. Activities included measurements of salinity, pH, dissolved oxygen, temperature and nutrients (NH4 +, NO2 -, NO3 -, PO4 3-, H4SiO4), biochemical oxygen demand (BOD), total and organic phosphorus (TP and DOP), particulate organic carbon (POC), suspended particulate material (SPM) and chlorophyll-a (Cla). The intratidal nutrient variations was also evaluated in the middle and low estuary, in december/1999. This survey included hourly measurements of the stream velocity, water level, SPM and nutrients in three fixed stations, during 25 hours (2 tidal cycles). Multivariate analysis showed that the main forcing factors causing the system variability were the river discharge, the marine influence, the urbanization and the rice culture. It was proposed that the system can be divided in riverine limit, and high, middle and low estuary. The urbanization was responsible by the spatial variation of the water quality, showing increases in the organic matter (BOD, NH4 +, POC and DOP) and progressive decrease of dissolved oxygen. Despite the effect of dilution by the marine waters, increasing in NH4 + was detected in the low estuary, which is probably related to the urban organic loads and the fisheries processing plants effluents. When the river discharge was low during a long time, increasing in NH4 + and NO2 - and severe decreasing in dissolved oxygen was observed. This situation could be an early indication of hypoxia in the estuary. River discharge increasing resulted in increased SPM, TP, NO3 - and Si. This trend was intensified by high soil exposition in the beginning of the rice culture cycle. In this period there was a decreasing in Si, suggesting influence of rice culture Si uptake. The nutrient budget showed that 50% of PO4 3- input was shifted in the middle and low estuary. This was probably related to adsorption to SPM, once chlorophyll-a in the estuary was relatively low. The non-conservative increase of NH4 + in the low estuary suggest a heterotrophic behavior, once the organic load and turbidity were generally high. The intratidal variation of nutrients showed to be lower than other regional estuaries and also seemed to be influenced by the surrounding area. The tendency of non-conservative increase of NH4 + was also evident and related to salinity values between 5 and 15, which occurred during the water mixing inside the estuary.

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Although public politics determine priorities in the evaluation of the development and in the accomplishment of the human well-being, this work considers the possibility in evaluating the degree of satisfaction of the population, based on the priorities and indicators from the population perspective. The subject assumes extreme outlines when related to the correct use of the public resources and of the failure of municipal programs destined to the residents mainly inserted in the urban outlying space. Evaluation of the degree of satisfaction of the population comes as a strategy to evaluate the impacts produced by the investments - publics or private - in projects of social development. In this study the population of a recent outlying neighborhood (Social Division into lots Antenor Garcia), of the city of São Carlos, SP, with approximately five thousand inhabitants, was considered. With base in the answers for a single open and synthetic question: What does you like and unlike in the neighborhood in what you live? ", a questionnaire with seventy six subjects contained in six variables: Health; Social; Education and Recreation; Safety; Habitation and Environment; and Transports, was elaborated. As for the form of the scale of the questionnaire it was adopted of the type LIKERT, with referencial of OSGOOD, with answers induced for Totally Disagree (DT); "Disagree Partially" (DP); "Without Opinion" (SO); "Agree Partially" (CP) or Totally Agree (CT). The consistence measures among the correlations were made with base in the coefficient Alpha of CRONBACH, that resulted in: medium to high correlation (>0.66) for internal analysis to the variables; and medium correlation (0.46), for inter-variable analysis - function of the correlated aspects (e.g. Safety versus Health). The variable Transports were the one that presented smaller degree of satisfaction - probably due to distance of the neighborhood downtown of São Carlos. While the item public illumination which belongs to the variable Habitation and Environment was the one with best degree of satisfaction - probably due to the appeal of some of the aspects of safety manifested by the habitants of this suburb. One expects that this methodology comes to contribute to deal with the conflict between the interests of the population and the urban planning, in way to understand and to assist the real needs of those populations, in the application of the public resources.

The genus Tabebuia in the family Bignoniaceae comprises about 100 species, several of which have medicinal, ornamental, and timber value, in addition to their environmental importance. These species produce large amounts of seeds, with a short viability period under natural conditions. In the present research, studies were developed on germination and conservation aspects of seeds in species of the genus Tabebuia. Initially, substrates were evaluated to be used in seed germination tests for the species T. aurea (Manso) Benth. & Hook., T. impetiginosa (Mart.) Standl., T. ochracea (Cham.) Standl., T. roseo-alba (Ridl.) Sand., and T. serratifolia (Vahl.) Nich. The following substrates were tested: on sand, on vermiculite, on sand+vermiculite, on paper (two sheets of blotting paper) and between sheets (two sheets of blotting paper under and one sheet over the seeds). For T. impetiginosa seeds, these substrates are suitable for use in germination tests. For the other species, the most suitable substrates were: on sand, on paper, and between sheets for T. aurea; between sheets for T. ochracea and T. roseo-alba; and on sand and between sheets for T. serratifolia. In another study we attempted to identify a suitable condition to store T. roseo-alba and T. impetiginosa seeds, as well as to evaluate methods to estimate alterations in the viability and vigor of those seeds. Different groups of seeds were placed in clear plastic bags, Kraft paper bags, and cans. The seeds were then stored for up to 300 days under laboratory, refrigerator, and refrigerated chamber conditions. Seed water content, germination percentage and velocity, and electric conductivity were determined at the onset of storage and thereafter at every 60 days. The best T. roseo-alba and T. impetiginosa seed conservation condition was obtained with cans maintained in the refrigerator. T. impetiginosa seeds can also be kept in plastic bags, paper bags, or cans when stored in refrigerated chamber. Seed vigor alterations in these species are initially identified based on germination velocity. In the third study, we evaluated accelerated aging effectiveness in detecting vigor variations in T. roseo-alba and T. impetiginosa seeds. Seeds of these species were submitted to accelerated aging under temperatures of 40 or 45ºC, for periods of 24, 48, 72, 96, 120, and 144 hours. After those periods, germination and plantlet emergence tests were conducted, and field emergence index values were calculated. We verified that accelerated aging is effective to detect seed vigor variations in T. roseo-alba and T. impetiginosa. When aging is conducted at 45°C, differences in viability and vigor occur first. Traits such as germination percentage and velocity, plantlet emergence, and incorporated biomass can be recommended as seed vigor indicators, using accelerated aging. Under more drastic accelerated-aging conditions, no correspondence is observed between data obtained in the field and in the laboratory.

This survey was carried out in a Araucaria Forest of an area of a legal reserve of Três Capões Farm and Trindade Farm, situated at south central of the state of Paraná, Brazil. The local climate is the tipe Cfb, don't have a dry season the average temperature is about 18oC at the more cold month. The average altitude is about 1250m cliff of scarp at 350m at Guarapuava region. The geomorfology is characterized by conver rill and largue valley originated on Quaternary. The forest in this study was sampled with transects positionaded at north, west, south and east, where the floristic surveyed was realized beyond the walk for all the area. A number of 144 species. The families with the highest number of species was Lauraceae (8,0%), Myrtaceae (8,0%), Solanaceae (7,2%), Euphorbiaceae (4,8%), Fabaceae (4,8%) and Verbenaceae (4,8%). Currently, forests are found as fragments inserted in a variety of matrixes. Hence, these fragments are under constant influence of the matrixes, fact known as edge effects. This work investigated the occurrence of edge effectsin the regulation of three Araucaria Forest fragments located in the south-center region of the Parana state, Brazil. Several approaches were realized in 12 transects of 4x100 m: floristic survey, density calculations, basal area, pioneer and secondary species, richness and behavior. A total of 3271 arborescent and arboreal specimens belonging to 152 species were sampled in the north, south, east and west side of the three forest fragments. There were no analyzed parameters that resulted in an expected pattern of edge effects. An ANOVA test was applied to analyze a correlation of the data with positioning (north, south, east and west) in each fragment. No significant correlation was detected in the fragments. The results are possibly related to the fact these fragments are not only under the edge effect, but also to the continous anthropic interference that could mask the known edge effects through the intensification of such interference farther than the first meters from the border to the interior of the fragment. This lead to another concern about this type of fragment because it could means a pure conservation of this vegetation, considering the small portion of conserved areas and discounted the edge effects.

Universidade Federal de Sao Carlos

This study sought to conceptually discuss organic farming, as part of agroecological science, and to assess its relationship with the current situation of supply of organic fruits and vegetables in different distribution channels in the city of Campinas-SP. The variables considered were price, form of product presentation, variety, packaging types, local production and certification. A comparison was performed with others grocers called "sanitized", "pre-washed", "selected" or "conventional" in this study were grouped under the name of "nonorganic". Ten points of sale was observed, eight hypermarkets, a Organic Fair and a Grocer Street Fair, typical of Brazil. All points are located within a radius of five kilometers from the city center. It was found that, despite the large growth of this market in Brazil, there is still a major bottleneck related to the presentation of products, the understanding of the organic concept, and accessibility to this product by consumers.

The aim of this work was to analyze the floristic composition and horizontal structure of a stretch of the arboreal vegetation in the Biological Reserve of Sooretama. The survey was restricted to a phytosociological sample done on one hundred contiguous portions of 10 x 10 meters. Individuals with PBH &#8805; 15 cm were sampled. The forest was segmented in three vertical strata, allowing EIV calculation. A meter and a meter width were used as first center class. A total of 1519 individuals were sampled, distributed in 265 species, 138 genera and 44 families. The Shannon s Index (H ) found was 4,87 nats. In relation to the threatened species, 16 consist in the Red List of Espírito Santo State. The Biological Reserve of Sooretama obtained 57% of similarity with the Natural Reserve of CVRD. The species Rinorea bahiensis (Moric.) Kuntze prevailed in the three strata, with has the largest EIV. The group of the late secondary stood out in all the strata. The stand was considered at advanced successional stage.

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