Sustainability of tilapia production systems

• Ano de defesa: 2021
• Autor(a) principal: David, Luiz Henrique Castro [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Ponds; Ecosystems; Tilápia
• Link de acesso: http://hdl.handle.net/11449/215448

Numerous systems, models, and production techniques have been developed to minimize the environmental impact of aquaculture and make this activity more sustainable. In this context, the thesis aims at developing and investigating sustainable production systems for tilapia farming in Brazil. The thesis comprises eight chapters. Chapter 1 brings a brief theoretical background, the research objectives and thesis approach and outline. Chapter 2 reviews the standards, potentialities, deficiencies, and applications of the emergy method in the sustainability assessment of aquaculture production systems. In this chapter, we also discuss and propose improvements on the emergy synthesis for measuring aquaculture sustainability. In Chapter 3 and 4, the sustainability of commercial tilapia production in aquaponics and biofloc-based systems were evaluated, respectively, using emergy synthesis. We also indicate alternative management to reduce systems’ issues and boost the sustainability of them. An innovative way to account for ecosystem services and disservices within emergy synthesis is proposed and discussed in Chapter 3 to accurately capture the environmental performance for aquaponics systems. The findings presented in Chapter 3 and 4 suggest that aquaponics and biofloc are systems potentially sustainable for tilapia farming in Brazil. However, improvements should be done in both food production systems to improve their sustainable performance. Chapter 5 and 6 investigate the technical feasibility of reducing the amount of feed in periphyton-based systems to produce tilapia in ponds and cages located in a farm dam. The tilapia growth performance presented in Chapter 5 indicates that the proposed production models are promising strategies for using natural food in a periphyton-based system and reusing effluents from monocultures. On the other hand, Chapter 6 shows that rearing tilapia in a farm dam with water poor in nutrients result in low availability of the periphyton and, consequently, the tilapia under feed restriction could not take advantage of the periphyton as natural food. In the study presented in Chapter 7, we show the consumer preferences and perceptions regarding the market for sustainable/certified aquaculture products in Brazil. As the main result of Chapter 7, we found that most Brazilian fish consumers are aware of what certification is and the aspects involved in it. In general, the set of information and findings presented in this thesis can be considered as an important step to support the development of public policies and certification programs to make aquaculture a more sustainable activity.