The purpose of this study is to investigate the hydrodynamic properties of an oyster floating raft system under environmental loadings. The floating raft system is an important facility for raising oyster in the near shore area of Tainan, Taiwan. The reasons for this kind of oyster culture being main income source for local fish farmers are as the following features: (1) low cost for the farming system, (2) easily to be installed in the field, and (3) easily to be harvested. Due to the raft structure could not withstand the impact of heavy storms; most of the oyster rafts are towed into harbor to avoid damage before the onset of typhoon. Since some unexpected violent sea states may occur and severely affect the integrity of raft system, the investigation of the hydrodynamic properties of a floating raft system is essential for oyster culture in the open sea. This study includes two parts: numerical simulation and physical modeling. In numerical simulation, a lumped mass method with a Morison type of relative motion equation are adopted to calculate the drag and inertial forces on raft components and then are equally divided to the associated nodes to form a system of motion equations based on Newton¡¦s second law. Through the fourth-order Runge-Kutta method, the dynamic performance of the oyster raft system can be obtained. To verify the numerical model, a physical model was carried out in a wave tank (35x1x1.2 m), and the results of dynamic performance of numerical model show good agreement with measurements. A case study of an in situ oyster farming system located near-shore of Tainan region is analyzed by the developed numerical model to investigate the maximum mooring tension, the optimal gap between rafts, and the required length of mooring line. These specifications are crucial to the shell fish farmers for their floating raft system to be survived in the strong currents and waves. The results showed that the optimum configuration for a raft system generated the lowest mooring tension is as the follows: the space between oyster rafts is about a length of oyster raft; the length of mooring line is three times of the water depth, which is consistent with the present practice of shell fish farmers adopting 3~4 times of water depth; the appropriate embedment anchor weight is 70 kg but the anchorage should be the type used by the farmers in Penghu county. Finally, this work intends to offer a guideline for the installation of oyster raft systems in the field, and anticipate minimizing the damage during the unexpected heavy sea states.

Offshore culture becomes the most attractive industry in last decades because of overfishing and excessively pumping groundwater causing land subsidence social problems. Oyster culture is one of offshore culture with several advantages such as easy set-up and without feeding cost. In this study, we focus on a longline-style oyster aquaculture system because it is recyclable, high growing efficiency and advanced technique against traditional tidal flat culture. This study establishes a numerical model through a lumped mass method, then employs fourth order Runge-Kutta method to solve the system of motion equations and evaluates the tension on the anchor rope. The results show the discrepancy between the numerical model and experimental data is lower than 4% in current-only situation, and similarly in wave-only situation the discrepancy is lower than 6%. The comparison results indicate that the numerical model is capable to predict the environmental loadings on longline-style oyster culture system. An in-situ case study of a longline-style oyster aquaculture system via regular and random waves, located in the Penghu Bay, is investigated based on the sea-state, Chebi Typhoon occurred in June, 2001, causing a catastrophic damage to the cage aquaculture. The conclusions of dynamic responses of the case study may be utilized as guidance for the local oyster farmers to build and protect their oyster culture system in the Bay.

<p>The pearl oyster <em>Pinctada martensii </em>or <em>Pinctada fucata </em>is the oyster for produce the South China Sea Pearl, and the production of pearl oyster <em>Pinctada martensii</em> plays a key role for the economic and social welfare of the coastal areas. To guarantee both rich and sustainability of providing pearl oyster productions, addressing the suitable areas for aquaculture is a very important consideration in any aquaculture activities. Relatively rarely, in the case of site selection research, the researchers use GIS analysis to identify suitable sites in fishery industry in China. Therefore, I decided to help the local government to search suitable sites form the view of GIS context. This study was conducted to find the optimal sites for suspended culture of pearl oyster <em>Pinctada martensii </em>using GIS-based multi-criteria analysis. The original idea came from the research of Radiarta and his colleagues in 2008 in Japan. Most of the parameters in the GIS model were extracted from remote sensing data (Moderate Resolution Imaging Spectroradiometer and Landsat 7). Eleven thematic layers were arranged into three sub-models, namely: biophysical model, social-economic model and constraint model. The biophysical model includes sea surface temperature, chlorophyll-α concentration, suspended sediment concentration and bathymetry. The criteria in the social-economic model are distance to cities and towns and distance to piers. The constraint model was used to exclude the places from the research area where the natural conditions cannot be fulfilled for the development of pearl oyster aquaculture; it contains river mouth, tourism area, harbor, salt fields / shrimp ponds, and non-related water area. Finally those GIS sub-models were used to address the optimal sites for pearl oyster <em>Pinctada martensii</em> culture by using weighted linear combination evaluation. In the final result, suitability levels were arranged from 1 (least suitable) to 8 (most suitable), and about 2.4% of the total potential area had the higher levels (level 6 and 7). These areas were considered to be the places that have the most suitable conditions for pearl oyster <em>Pinctada martensii </em>for costal water of Yingpan.</p>

The pearl oyster Pinctada martensii or Pinctada fucata is the oyster for produce the South China Sea Pearl, and the production of pearl oyster Pinctada martensii plays a key role for the economic and social welfare of the coastal areas. To guarantee both rich and sustainability of providing pearl oyster productions, addressing the suitable areas for aquaculture is a very important consideration in any aquaculture activities. Relatively rarely, in the case of site selection research, the researchers use GIS analysis to identify suitable sites in fishery industry in China. Therefore, I decided to help the local government to search suitable sites form the view of GIS context. This study was conducted to find the optimal sites for suspended culture of pearl oyster Pinctada martensii using GIS-based multi-criteria analysis. The original idea came from the research of Radiarta and his colleagues in 2008 in Japan. Most of the parameters in the GIS model were extracted from remote sensing data (Moderate Resolution Imaging Spectroradiometer and Landsat 7). Eleven thematic layers were arranged into three sub-models, namely: biophysical model, social-economic model and constraint model. The biophysical model includes sea surface temperature, chlorophyll-α concentration, suspended sediment concentration and bathymetry. The criteria in the social-economic model are distance to cities and towns and distance to piers. The constraint model was used to exclude the places from the research area where the natural conditions cannot be fulfilled for the development of pearl oyster aquaculture; it contains river mouth, tourism area, harbor, salt fields / shrimp ponds, and non-related water area. Finally those GIS sub-models were used to address the optimal sites for pearl oyster Pinctada martensii culture by using weighted linear combination evaluation. In the final result, suitability levels were arranged from 1 (least suitable) to 8 (most suitable), and about 2.4% of the total potential area had the higher levels (level 6 and 7). These areas were considered to be the places that have the most suitable conditions for pearl oyster Pinctada martensii for costal water of Yingpan.