Refined three-dimensional numerical simulation of velocity field and seston flux within a scallop-fishing net cage

Abstract

With the expansion of aquaculture, its impacts have become increasingly important. The environmental impact of suspended aquaculture is dependent upon the farmed species, production intensity, and farming conditions. A refined three-dimensional lattice Boltzmann model was established and validated, and was then used to simulate flow field and seston distribution within a net cage used for scallop fishing. Simulations were carried out in order to analyze the influences of the number of scallops and the current velocity on the local environment (flow velocity, seston flux, and local seston consumption). The results indicated that the reduction of flow velocity and seston flux are related to the number of scallops in the net cage such that a higher velocity/seston flux drop results from a larger amount of scallops. The results also implied that the seston flux and scallop number lead to variable local seston consumption. This study provides fundamental information on the hydrodynamic and seston conditions in net-cage scallop fishing, which have potential application in managing the scale of scallop-fishing and the environmental impacts of suspended-cage aquaculture.