E-Thesis 529 views 161 downloads
Microalgae in aquaculture feeds for Nile tilapia, and the feasibility of urban aquaponics / SAMUEL FILES
Swansea University Author: SAMUEL FILES
Abstract
This thesis develops understanding of microalgae in Nile tilapia (Oreochromis. niloticus) feed, implications for aquaponics and how consumer perceptions influence feasibility of urban aquaponics. Aquaponics is the growing of crops, utilising nutrients from fish waste. Chapter one is a meta-analysis...
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Swansea
2022
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| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MSc by Research |
| Supervisor: | Garcia de Leaniz, Carlos ; Consuegra, Sofia |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa61646 |
| Abstract: |
This thesis develops understanding of microalgae in Nile tilapia (Oreochromis. niloticus) feed, implications for aquaponics and how consumer perceptions influence feasibility of urban aquaponics. Aquaponics is the growing of crops, utilising nutrients from fish waste. Chapter one is a meta-analysis (36 papers) on the effects of microalgae inclusion on O. niloticus. This was done to determine if fish meal (FM) in aquaculture feeds can be replaced with microalgae, without being detrimental, to reduce pressure on wild fish stocks. An inclusion of microalgae, up to 30%, is beneficial to O. niloticus with no detrimental impacts. Effect sizes for specific growth rate (-0.15) and feed conversion ratio (-0.30) indicate microalgae can replace FM. Chapter two assesses effects of feed on water parameters (Ammonia etc) in O. niloticus systems, by systematic review. Optimal water parameters for O. niloticus are understood, but effects of feed type and quantity are poorly researched, which needs rectifying. Feed type has little importance, and feed quantity has overriding impact on water parameters. Chapter three investigates palatability of digestate cultured microalgae (DCM, Nannochloropsis & Scenedesmus), cultured on membrane microfiltered, food waste digestate on O. niloticus, assessing the possibility of DCM as an alternative to FM. Time to react, pellets eaten and ejected determined palatability. There were no statistically significant results (P>0.05), indicating that an alternative feed is as palatable as commercial feed. Chapter four examined feasibility of urban aquaponics via a consumer survey (254 participants), as future innovative farming will utilise space in urban areas (Biophilic living project). It created a baseline of perceptions in the UK, which could tailor systems/inform public on aquaponics based on current knowledge. 30% of participants had heard of aquaponics, but showed reservations to costs. Attitudes are neutral or in favour to aquaponics, but considerations are needed for location, product choice and system design. |
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| Item Description: |
ORCiD identifier: https://orcid.org/0000-0002-3889-2089 |
| Keywords: |
Microalgae, Nile tilapia, Digestate, Aquaponics, Feed, Consumer perceptions |
| College: |
Faculty of Science and Engineering |