RIASSUNTO
In this study, the experiments of a 1:30 scale model of a flexible circular net cage with the mooring system are conducted in the circulating flume. For geometry and motion measurements, a non-invasive stereo imaging method is employed, which use three CCD camera systems to take the 2D photos and then transform to 3D visional sketches. Results of this experiment show that it has highly mutual dependency between the tension force and the deformation of a flexible net structure. Furthermore, the evolution change of three-dimensional deformation and motion of the net cage are also investigated. INTRODUCTION As the world’s population increases, so does the demand for seafood including marine finfish. Landings of marine finfish, however, are beginning to plateau with nearly 50% of the major stocks fully exploited (Food and Agriculture Organization of the United Nations, 2000). While the capture fisheries are reaching their full potential, aquaculture continues to expand. Recently marine cage aquaculture is expected to be an increasingly important role in the fish production industry in worldwide. Marine aquaculture has been predominantly in protected near-shore waters (Panchang et al., 1997). In Taiwan, as well as in other countries, this has resulted in an increasing number of fish farms installed near-shore area. While for recent activity in cage aquaculture development in Taiwan, there are still significant biological, engineering and socio-issues that need to be resolved before cage aquaculture instead of in-land fisheries. A major constraint to marine aquaculture development in Taiwan is the suitable water space. As environmental and ecosystem issues existing near shore aquaculture facilities, it needs to move aquaculture operations into more exposed sites. Therefore, the feasibility of extending operations into the energetic open ocean has recently been addressed. However, such a transition is not trivial because the suitable species and technologies for this energetic environment are not yet developed to a viable economics scale.