Diving into aquaculture fish farming: investigating factors affecting daily growth of barramundi using otoliths

• Main Author: Gooi, Jia Yi
• Other Authors: Joyce Ong
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Science::Biological sciences::Zoology::Vertebrates
• Online Access: https://hdl.handle.net/10356/156710
• Institution: Nanyang Technological University

Otoliths, which are calcified structures located in the inner ear of fishes, are useful tools for studying the biology of fishes. This information is crucial for determining factors that affect daily growth in aquaculture fishes. My study examined the daily growth of juvenile barramundi (Lates calcarifer), a commercially important aquaculture fish globally, by measuring the daily increment widths of otoliths. The first aim of my study was to establish that daily rings from aquaculture barramundi were adequate for growth analysis. The second aim was to identify the external factors affecting daily growth, such as temperature and tank treatments performed to protect or battle against diseases. Sagittal otoliths were extracted from 50 barramundi obtained from a Singapore aquaculture farm, sectioned and read under a stereo microscope. Daily increment widths were measured, and linear mixed models were used for analysis. Daily otolith rings were found to be distinct and consistent throughout the otolith, and hence adequate for analysis. My results showed that daily growth was influenced by 4-day lagged sea surface temperatures, with an optimal temperature approximately 29.6°C. Tank treatments (antibiotics, formalin and heating) did not have a significant impact on growth. However, future analysis should be performed to better refine possible impacts from tank treatments. With the threat of rising sea surface temperatures, my findings suggest that growth of aquaculture barramundi in Southeast Asia might decrease in the future. As such, fishery managers should take precautions if they were to sustain or improve their production.