The fish cage system consists of netting, mooring ropes, a floating collar, floats, sinkers and anchors. Whole elements of the cage system were modeled on the mass-spring model. The modeling method was applied to the dynamic simulation of the actual fish cage system simultaneously influenced by the current and waves in order to evaluate their practicality. Computer-based simulation provides a method to quantitatively analyze the environmental forces acting on fish cage systems and thereby provides valuable information necessary for designing an optimal structure.
In recent activity in fish cage systems, the increased attention is being focused on extending operations into the open ocean in order to avoid conflicts in the near-shore areas. To design reliable systems that can withstand the severity of open ocean, stricter design criteria and novel engineering methods specific to open ocean environments are needed. Such methods include mathematical modeling of the dynamic responses of structures placed in high energy open ocean areas and 3-D simulation of the ocean environmental loads that would act on aquaculture systems. Fish cage systems consist of netting, mooring lines, a floating collar, floats, and sinkers. Netting, ropes, and a floating collar are the basic components of marine cage structures. Much research has been devoted to understanding the hydrodynamic coefficients and the behavior of the nets in different operating conditions (Aarsnes et al., 1990; Bessonneau and Marichal, 1998; Lee et al., 2005; Kim et al., 2007). Recently, many researchers have conducted computer-aided behavior analysis of fish cage systems (Tsukrov et al., 2003, 2005; Fredriksson et al., 2003, 2007; Lader and Enerhaug, 2005; Haung et al., 2006, 2007; Li et al., 2006; Zhoa et al., 2007). In this study, we propose a mass-spring model to describe the whole elements of a fish cage system, including the floating collar.