Análise de parâmetros físico-químicos e biológicos no sistema intensivo de produção de tilápia do Nilo

• Ano de defesa: 2014
• Autor(a) principal: Pires, Tatiani Botini
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Departamento de Zootecnia; Programa de Pós-Graduação em Zootecnia; UEM; Maringá, PR; Centro de Ciências Agrárias
• Palavras-chave em Português: Tilápia do Nilo; Oreochromis niloticus; Cultivo; Reservatório; Produção; Oxigenio; Aquicultura; Bioindicadores; Oligochaeta; Tanque-rede; Brasil.; Aquaculture; Bio indicators; Oxygen; Reservoir; Cages; Brazil.; Ciências Agrárias; Zootecnia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/1494

This work was performed at the Crow River, a tributary of Rosana reservoir (RP/SP) located in the area between the towns of North Diamond (PR) and Terra Rica. 18,000 juveniles post-reversed for male of Nile tilapia (O. niloticus), from the variety GIFT were used. From these animals the biomass data at intervals of approximately thirty days were collected in the summer period, to determine the feeding management. The evaluation of limnology, temperature, dissolved oxygen, oxygen saturation, electric conductivity and transparency were determined in situ. For these were used a sampling interval of about fifteen days and were evaluated at three levels of the water column; while the evaluation of the levels of total nitrogen, orthophosphate and nitrate occurred at intervals of thirty days and in two levels of the water column. Limnological data were collected at an interval of four hours between each repetition in the day. The collection of aquatic macroinvertebrates occurred through a method of natural colonization, called bio collector, made from a plastic net with a capacity of five kilos and using as substrate 15g of Cattail (Typha sp.), 10 cm of plant bush and about 450g of crushed stone and gravel, with six replicates for each point. One triplicate of bio collectorswas exposed for about 15 days and the other three for about 30 days from the date of its implementation. The data of the limnological variables were subjected to descriptive analysis and variance (Anova) and means were compared by the Scott-Knott test at 5% probability. A statistical analysis using the Poisson distribution with log link function to the data obtained by counting identifiedaquatic macroinvertebrates was applied. The number of individuals and the richness were used to evaluate: collection points established; transects formed with the deployment of cages; the effect of stocking densities of fish in cages and the exposure time of bio collectors. The system of cultivation in cages caused a significant variation (P<0.05) in oxygen content and pH. On average in the transect without cages the saturation by oxygen, and the oxygen dissolved in water is 2.9% and 0.24 mg/L to higher than the available transects in cages, with significant difference (P <0.05) between these transects. But even with the effect of fish farming indexes of water quality evaluated have not breached the levels imposed by Resolution No. 357/2005 of Conama, indicating that the environment has the capacity to assimilate mitigating the impact of fish farming organic load imposed by the activity in function of waste from feed and fish excreta. The sampling method of benthic macroinvertebrate communities was more efficient in the environmental monitoring than thelimnological variables, confirming that the increase of organic matter increases the density of these organisms, especially the group of Oligochaeta, Hirudinea and Gastropoda. These results demonstrate the importance of studies in this area to define more precisely the methodological procedure and studies aboutthe responses of groups of benthic macroinvertebratesin function of aquaculture production activities.