Session: 13-01-02 Blue Economy II

Paper Number: 101407

101407 - Hydroelastic Response of Submersible Open Net Fish Pens Under Wave Action 

There are strong push and pull factors for moving nearshore fish farms to offshore sites. Push factors include limited and contested nearshore sea space for aquaculture farming and stressed eco-system in shallow and sheltered farm sites. Pull factors include large and uncontested sea space in offshore sites, pristine waters, more effective dispersion of faecal and waste feed, and flushing of net cages due to stronger mixing and currents. However, one of the most challenging aspects of offshore fish farming is the survivability of the fish pens and well-being of fish within the pens during severe storms that are accompanied by very strong surface waves. Recent offshore fish pen designs such as Ocean Farm 1, Havfarm 1 and Shen Lan 1, tend to be robust to withstand strong waves and have extremely large farming volume (housing over a million salmon) to enjoy the economy of large-scale production. However, these large and robust fish pens do not come cheap, costing over 100 million US dollars. A cost-effective solution for storm proofing fish pens at offshore sites is by using a flexible material and having submergibility capability via ballast tanks. During storms, the fish pens may be resilient to strong waves or submerged to an appropriate depth for a calmer water environment and re-floated to the surface after the storms have passed. In this study, we aim to investigate the hydroelastic response of flexible open net fish pens of different submerged depths. Also, we wish to quantify the forces in the mooring lines. The hydroelastic analysis will be performed by using AquaSim which is a dedicated time-domain FEA software for analysing aquaculture infrastructure under wave, current and wind actions. The findings of this study will provide useful information to the aquaculture industry on the deformation and survivability of open net fish pens in offshore sites during storms.

Presenting Author: Yun Il Chu Griffith University

Presenting Author Biography: Dr. Yunil Chu is currently working as a Postdoctoral Research Fellow at Cities Research institute, School of Engineering and Built Environment, Griffith University, Australia. He received his PhD from the School of Civil Engineering, The University of Queensland, Australia in 2021. His research focuses on developing novel solutions for offshore fish farms. Prior to his PhD study, he worked as a design approval engineer for 11 years (2007~2017) in DNV. He led over 20 design approval projects for Ships & offshore newbuilding constructions, and delivered high quality solutions for design development & optimization and remedy plans against structural defects and damages. His knowledge and experience on the offshore engineering for various objectives can make high level of research portfolio and quality more competitive and outstanding in academic research field, which would create new opportunities to engage with industry partners.

Authors:

Yun Il Chu Griffith University
Chien Ming Wang The University of Queensland
Xinyu Zhang Griffith University
Hong Zhang Griffith University
Leigh Savage Huon Aquaculture Group Ltd.