Piscicultura e manejo da qualidade da água

Fish farms' water quality management is analyzed with regard to the management employed and the different trophic states are compared within the system during the dry and rainy seasons. Six sites were marked two in the water supply (P1 and P2), and four within the fish farm (P3 to P6). Whereas sites P1 and P2 (water supply) were characterized as oligotrophic, the others were mesotrophic and eutrotrophic sites. Environmental variables, mainly nutrients, conductivity, COD, BOD5 and TSS tended to increase as from P3 due to management and fertilization. Greater impact has been registered in the fish farm under analysis for variables COD, ammonia, total phosphorus and TSS during the discharge and pond emptying period. Frequent monitoring of water quality should be undertaken in fish breeding and plankton production ponds, especially in those close to P3 and P4. Removal of sediment in decantation lake or P5 is also recommended to decrease nutrient concentrations, especially phosphorus, accumulated on the bottom soil.

Desempeño de tanques decantadores de sólidos en un sistema de recirculación para producción de tilapia

To compare the removal efficiency of solids, turbidity and apparent color between a conventional and a column settling tanks in a recirculating aquaculture system (RAS) for tilapia farming. Materials and methods. Tilapia with a stocking density between 30 and 33 kg/m3 were cultured in a RAS consisting of a water level control box, PVC piping system, three plastic tanks for culture, conventional horizontal flow settling tank (Con.ST), column vertical flow settling tank (Col.ST), three phase fluidized bed reactor, oxygen transfer reactor, air compressor, air blower, centrifugal pump. The Con.ST operated at a volume of 1.4 m3 and hydraulic retention time (HRT) of 2.94 h; and was drained weekly for washing and sludge collection, representing a 55%discharge of system water volume. The Col.ST operated with a volume of 0.30 m3 and HRT of 0.553 h. Three daily partial draining operations were executed, representing a discharge of 50% of the system volume. Results. The mean solids removal efficiencies were: 34.01 and 44.44%for total solids; 64.45 and 71.71% for suspended solids; 21.10 and 45.65% volatile solids; 65.51% and 62.79% for turbidity; and 56.37 and 50.91% for apparent color, respectively for Con.ST and Col.ST. Conclusions. The two settling devices are useful on removal of the studied parameters and presented similar performance on turbidity and apparent color removal; however, the Col.ST was more efficient than Con.ST for solids removal, requires less space, less volume and requires less discharge water volume, displaying feasibility for its use on RAS.

Influência de uma piscicultura em tanquesrede na dieta e atributos biológicos de Galeocharax knerii na represa de Chavantes, Brasil

The aim of the present study was to evaluate the diet and biological attributes of the population of Galeocharax knerii residing near net cage fish farming activities in the Chavantes reservoir (Paranapanema River, Brazil) to check their possible impacts. Samples were collected from two populations: one near the net cages (NC) and one from an area not influenced by these cages denominated the reference site (RS). Monthly sampling was carried out from March 2008 to February 2009. Fish were caught with a standardized effort using gill nets deployed for 14 hours. The alimentary index (AI) and degree of repletion (RD) were calculated to determine diet composition. Analyses of the sex ratio and the gonadosomatic index (GSI) were also performed. The calculations of AI revealed that fish wastes constituted the most frequent food item in the diet in both study areas (NC = 70.43; RS = 87.55), followed by the consumption of Apareiodon affinis (AI = 29.56), which was abundant near the NC, and prawn at the reference site (AI = 12.28). The sex ratio differed from 1:1 and mature individuals were only found in the population near the NC. The findings demonstrate that G. knerii indirectly benefits from the input of organic matter, using small fish as its main food resource. We conclude that the activities of fish farming influence diet and biological attributes of the species G. knerii, evidenced mainly by higher feeding activity, numerical abundance and biomass in the area of the cages.

Fator Pró-digestão inicial® e Isoterápico® na larvicultura da tilápia-do-Nilo: avaliação do índice de parasitismo, integridade hepática e branquial

Pós-graduação em Aquicultura - FCAV

Avaliação limnológica em um sistema de piscicultura na região de Paranaíta (MT, Brasil)

Pós-graduação em Aquicultura - FCAV

Desenvolvimento ovariano do Prochilodus lineatus em dois sistemas de produção: tanques rede e viveiros escavados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tratamento de efluentes de piscicultura utilizando sistema tipo wetland povoado com espécies de macrófitas aquáticas de três tipos ecológicos diferentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dinâmica da qualidade da água em tanques de peixes de sistema pesque-pague: aspectos físico-químicos e plâncton

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Projeto, desenvolvimento e avaliação de um penetrômetro elétrico-eletrônico para uso em tanques de solo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Projeto mecânico e análise térmica de tanques cilíndricos verticais com agitação e superfície de troca de calor

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Projeto e análise térmica de tanques de resfriamento de leite de cabra in natura para quatro ordenhas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização citogenética e molecular das espécies pintado (Pseudoplatystoma corruscans), cachara (Pseudoplatystoma reticulatum) e seus híbridos utilizados na piscicultura brasileira

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Indicadores de qualidade microbiológica, físico-química e detecção de resíduos de antimicrobianos no leite de vacas colhidos de tanques de expansão individuais, tanques coletivos e leite informal na região do estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diversidade bacteriana em piscicultura neotropical

Pós-graduação em Microbiologia Agropecuária - FCAV

Qualidade da água e identificação da comunidade fitoplanctônica de um viveiro de piscicultura utilizado para irrigação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)