Concentração de bioflocos no cultivo de Litopenaeus vannamei: Há um consenso?
Data
2022-11-18
Autores
Baccarat, Roberto Fábio Conway 
Orientadores
Schveitzer, Rodrigo
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A tecnologia de cultivo com bioflocos representa uma alternativa aos sistemas tradicionais de produção de camarões, que precisam renovar a água dos tanques para remover suas excretas (e.g., amônia). No sistema de bioflocos, há pouca renovação de água e isso é possível já que bactérias e microalgas presentes na água removem a amônia. Esses micro-organismos crescem na água dos tanques de cultivo na forma de agregados ou flocos microbianos (bioflocos). Entretanto, a quantidade de bioflocos aumenta durante o cultivo, podendo provocar, por exemplo, a obstrução das brânquias e morte dos animais. Dessa forma, considera-se que algum nível de controle sobre a concentração de flocos, que podem ser quantificados pela concentração de sólidos suspensos totais (SST), é necessário para a boa performance do sistema. Alguns autores sugerem níveis apropriados de SST para o cultivo do camarão Litopenaeus vannamei no sistema de bioflocos (BFT). Contudo, resultados de pesquisas subsequentes contradizem alguns dos argumentos que justificam os limites de sólidos sugeridos (e.g., a relação entre o aumento dos sólidos, a obstrução das brânquias e a sobrevivência dos camarões). Pesquisas recentes também mostram a relação do controle do nível de sólidos com outros aspectos importantes do sistema (e.g. controle de bactérias oportunistas), desconsiderados até então. Dessa forma, rediscutir esse tópico parece necessário e pode ajudar na busca de novos valores orientadores sobre quais concentrações de bioflocos podemos usar no cultivo de L. vannamei. Nesta revisão, são abordados os motivos que levaram ao estabelecimento dos níveis atuais de bioflocos para o cultivo de camarões e suas limitações. Também são analisados os efeitos da manutenção de níveis baixos e altos de flocos sobre o sistema de cultivo, destacando as vantagens e desvantagens. Por fim, avaliou-se novas possibilidades para o manejo da quantidade de flocos. Considerando o conhecimento atual sobre o tema, é possível dizer que valores de SST maiores que 600 mg L-1 (defendidos atualmente como sendo mais apropriados para o cultivo) são aplicáveis para o cultivo de L. vannamei no sistema BFT.
Biofloc technology represents an alternative to traditional shrimp farming systems, which need to renew pond water to remove the excreta produced by cultured organisms (e.g., ammonia). In the biofloc system, there is little water renewal, and this is possible since bacteria and microalgae present in the water remove ammonia. These microorganisms grow in the culture tanks in the form of microbial aggregates/flocs (bioflocs). The quantity of bioflocs increases during the culture, which can promote, for example, obstruction of the gills and death of the animals. Thus, some level of control on the flocs, which can be quantified by total suspended solids concentration (TSS), is considered necessary for adequate system performance. Some authors suggest appropriate levels of TSS for Litopenaeus vannamei culture in biofloc technology (BFT). However, subsequent research results contradict some of the arguments that justify the suggested solid limits (e.g., the relation between increased solids, gills obstruction and shrimp survival). Recent research also showed the relationship between solids control and other important aspects of the system (e.g., microbial control), disregarded until now. In this way, it seems necessary to discuss this topic once more, and it may help find new guiding values about what levels of bioflocs we should or could use in L. vannamei culture. In this review, we address the reasons that led to the establishment of current biofloc levels in shrimp culture and their limitations. We also analyzed the effects of maintaining low or high floc levels on the culture system, highlighting the advantages and disadvantages. Finally, we consider new possibilities for the management of flocs concentrations. Considering the current knowledge on the subject, it is possible to say that values of TSS greater than 600 mg L-1 (currently defended as being more appropriate to the culture) are applicable for the culture of L. vannamei in the BFT system.
Biofloc technology represents an alternative to traditional shrimp farming systems, which need to renew pond water to remove the excreta produced by cultured organisms (e.g., ammonia). In the biofloc system, there is little water renewal, and this is possible since bacteria and microalgae present in the water remove ammonia. These microorganisms grow in the culture tanks in the form of microbial aggregates/flocs (bioflocs). The quantity of bioflocs increases during the culture, which can promote, for example, obstruction of the gills and death of the animals. Thus, some level of control on the flocs, which can be quantified by total suspended solids concentration (TSS), is considered necessary for adequate system performance. Some authors suggest appropriate levels of TSS for Litopenaeus vannamei culture in biofloc technology (BFT). However, subsequent research results contradict some of the arguments that justify the suggested solid limits (e.g., the relation between increased solids, gills obstruction and shrimp survival). Recent research also showed the relationship between solids control and other important aspects of the system (e.g., microbial control), disregarded until now. In this way, it seems necessary to discuss this topic once more, and it may help find new guiding values about what levels of bioflocs we should or could use in L. vannamei culture. In this review, we address the reasons that led to the establishment of current biofloc levels in shrimp culture and their limitations. We also analyzed the effects of maintaining low or high floc levels on the culture system, highlighting the advantages and disadvantages. Finally, we consider new possibilities for the management of flocs concentrations. Considering the current knowledge on the subject, it is possible to say that values of TSS greater than 600 mg L-1 (currently defended as being more appropriate to the culture) are applicable for the culture of L. vannamei in the BFT system.
Descrição
Citação
BACCARAT, Roberto Fábio Conway. Concentração de bioflocos no cultivo de Litopenaeus vannamei: Há um consenso? 2022. 43 f. Dissertação (Mestrado em Bioprodutos e Bioprocessos) - Instituto do Mar, Universidade Federal de São Paulo, Santos, 2022.