Session: 05-02-01 Aquaculture and Related Technology I

Submission Number: 156437

Influence of Ocean Currents and Stocking Density on the Dissolved Oxygen Distribution Inside Gravity-Type Fish Cages 

Aquaculture has been the world’s fastest-growing food production sector over the past 40 years. Recently, offshore aquaculture offered notable benefits for fish welfare due to improved water exchange and waste dispersal. However, high current speeds can lead to fish exhaustion and weight loss, while low currents reduce the supply of the dissolved oxygen, posing challenge to maintain fish welfare. Understanding the dissolved oxygen levels and their relationship with the current speeds at offshore sites is crucial for sustainable ocean-based fish farming. This study investigates the influence of current speed on dissolved oxygen distribution for fish in gravity-type cages under a low oxygen level through numerical simulations. The simulations are carried out using the framework of a finite volume method in OpenFOAM. A new solver is developed by coupling with a dynamic porous media model for the cage nets in the fluid domain and a modified extended position-based dynamics (XPBD) for the deformations of the fish cages. The solver is also combined with an additional model based on the scalar transport equation of the dissolved oxygen concentration. The deformations of the fish cages, the flow velocity and the dissolved oxygen distributions obtained by the coupled numerical simulations are presented and analysed.

Presenting Author: Xueliang Wen University of Stavanger

Presenting Author Biography: Dr. Xueliang Wen is currently a researcher in University of Stavanger. He is working on the numerical modelling on
ocean fish farming, floating dock operations, floating wind turbines and water entry problems.