Net cages are mainly located on the coastal areas of Peng-hu and Ping-tung counties. Generally, there are two kinds of disasters occurred in the fish farming industries: one is caused by typhoon attack, while the other is caused by human vandalism. This paper is focus on how to prevent the damages induced by poaching or vandalism. Since high-valued fish are raised in the net cages, they are often become the targets of illegal intruders for stealing at night, especially when the net cages are lack of security system. Under such unsecured situation, entrepreneurs would not dare to invest in this industry and may keep a suspicious attitude towards it. Compare to land aquaculture, marine aquaculture is far more complicated in terms of techniques involved in production progress. Surely over-fishing has serious deplete the stock of biomass in the sea in the past decades. Recently, the skyrocketed oil price even deteriorate the fishing industry to such a level that fishing boats can only operate for a season in each year and end up losing money. However, Fisheries Agency has planned to recycle commercial fishing boats, and hopefully by doing so, this aquacultural industry will turn into a new trend in the near future. This research looks into 700 hectares of net cage park, Southern Oceanic Park, and suggests that the fishery authority turn this area into special district, adjust the fishery law, designate San-fu port as the park¡¦s operation center, finally set up a security system, then we may reduce the damage caused by unlawful activities. The geographical make-up of Liu-chiu provides ideal conditions for the present net cage area. The sea waters outside of San-fu port are also blessed with the same geographical advantage. This research looks at ¡§man-made calamities¡¨, namely vandalism and theft, so as to prevent damage and loss and protect resources and equipment. The areas chosen for this study include the surrounding sea waters of Liu-chiu aquaculture zone and the highly representative San-fu fishing port. There are also discussions on the installation of automatic alarm system in the eventual marine park. As an officer in a law enforcement administration for coastal affaires, my past contact with net cage fishermen revealed the damage and loss they have been undergoing and their sense of helplessness. On top of that, relevant documents turned out to be insufficient. Therefore, this research aims to figure out a way to fill this security gap by integrating public power from governmental services with protection and safety solutions on the part of individuals. To put this initiative to work, it is necessary to map out a special marine park where security mechanism could be automatically triggered by local facilities. This will then allow public power and personal endeavor to work simultaneously in the special zone and prevent any illegal activities. With its high applicability and pertinence, the eventual security system will hopefully entice more entrepreneurs, thus maintaining a sound net cage aquaculture.

This study investigates the tempo-spatial distribution in species composition and abundance of planktonic pteropods in relation to hydrography in the waters around Liu-chiu Yu Island, southwestern Taiwan from February 2006 to October 2007. In total, we recognized 25 pteropod species belonging to 12 genera and six families, with a mean abundance of 7348 ¡Ó 994 ind./ 1000m3. The five most dominant species were Limacina inflata, Creseis virgula var. conica, Creseis acicula, Limacina trochiformis and Creseis clava, together they accounted for 78.7 % of the total pteropods. The surface sea water temperature, salinity, and phytoplankton concen- tration in the waters around Liu-chiu Yu Island were significantly higher in 2006 than in 2007. Pteropod abundance was higher in spring than in other seasons, and higher in deeper waters than in surface waters. Species number of pteropods was significantly higher in 2007 than in 2006, generally higher in summer and lower in autumn, and higher in deeper waters than in surface waters. Species diversity index of pteropods was generally higher in summer and lower in autumn. Cluster analysis of hydrography included 4 clusters (e.g., 2007 summer, summer and autumn, spring and winter, spring), the 2007 summer cluster was different from other seasons. Pteropod assemblage showed apparent difference between seasons, the variation of pteropod assemblages between stations in spring was higher than other seasons. Linear regression showed that the species number (p < 0.01) and diversity index (p < 0.05) were positively correlated with abundance of fish larvae. Abundance of most dominant species of pteropods was significantly and positively correlated with abundance of fish larvae (e.g., Limacina inflata; Creseis virgula var. conica and Limacina trochiformis) and significantly and negatively correlated with phytoplankton abundance (e.g., Limacina inflata, p < 0.001). In addition to the hydrographic factors, the distribution of pteropods might also be affected by predatory fish larvae and phytoplankton supplement.

Persistent organic pollutants (POPs) have attracted the attention of scientists because they have the following characteristics: long-distance transmission, persistence, bioaccumulation and chronic toxicity. Due to their high hydrophobicity, POPs are easily absorbed by the suspended particles in the marine environment. The suspended particles then settle into the soil may pass through the food chain, resulting in bioaccumulation and biomagnifications and causing potentially hazardous effects on the environment and human health. This study focuses on the analysis of the persistent organic pollutants in different parts of 10 kinds of benthic fishes, including the muscle and visceral mass, adjacent to Hsiao-Liu-Chiu. The samples were analyzed using accelerated solvent extraction (ASE), and alumina column purification. Fifteen polycyclic aromatic hydrocarbons (PAHs) were determined by using gas chromatograph / mass spectrometer (GC/MS). After florisil column purification, polychlorinated biphenyls (PCBs) and 18 organochlorine pesticides (OCPs) were determined by using gas chromatograph / electron-capture detector (GC/ECD). The results showed that the concentration of PAHs range from 15 to 195 ng/g dw, with low ringed (3 rings) PAHs at a higher proportion. Total PCB concentrations range from 16 to 237 ng/g dw. The content of PCBs in muscles mainly consists of low chlorine numbers (1 to 4 chloride) -based, and in visceral and eggs the chlorine number (6 and 7 chlorine) are higher. The concentrations of OCPs range from 13 to 127 ng/g dw. Among the hexachlorocyclohexane (HCH) series, £^-HCH has the highest proportion, indicating the continued use of Lidane in recent years. In addition to the variance in POP levels among different species of fishes, different tissues also have high variations in PAH, PCB and OCP levels.

Abstract There are 22 species of chaetognaths belonging 11 genera and 4 families found in coastal waters around the Kaohsiung and Liuchiu Yu Island from March 1997 to February 1998. The average abundance of chaetognaths was 2527 ¡Ó1659 ind./100m3. The 5 most dominant species were Flaccisagitta enflata, Aidanosagitta crassa, Sagitta bipuncata, Ferosagitta ferox and Serratosagitta pacifica, and comprised > 95% of total chaetognaths. Fl. efnlata was the most common and abundance species, its number occupied 70% of total chaetognaths and occurred in every station. These dominant species showed significant seasonal succession, in that, Fl. Enflata could be found in all seasons, while S. bipuncata was found only in fall and winter. Most of chaetognaths found in this study were pelagic, tropical and temperate species, and most of them are widely distributed in the Pacific, the Atlantic and the Indian ocean (50% of total species), and in the Indian and the Pacific ocean (41% of total species). In terms of ecological distribution patterns, warm euryhaline species (i.e. Fl. Enflata and Fe. ferox), and warm hyperhaline species (i.e. S. bipuncata and Se. pacifica) dominated in this study areas. The abundance of chaetognaths was higher in fall (4721 ¡Ó8435 ind./100m3) and the lower in spring (1077 ¡Ó995 ind./100m3). The horizontal distribution of chaetognaths was apparently influenced by the runoff of Kaohsiung Habor and Kaoping River, and the peak abundance was usually found in the front of Kaoping river plume. Most chaetognaths (over 60% of total amount) were found in the surface waters (0-5 m), and its abundance abruptly decreased with depth. The scales of day/night vertical migration of chaetognaths were small (generally less than 50 m). Three types of vertical migration were distinguished in this study: Nocturnal migration (i.e. Fl. Enflata and Se. pacifica). Reverse migration (i.e. S. bipuncata ), and Non-migration (i.e. Fe. ferox). The vertical distribution and the distance of vertical migration of most chaetognaths, however, varied seasonally.

The objective of this study is to investigate and characterize the mechanism of the island wake behind an island called Liu Chiu Yu off the southwestern Taiwan coast based on the in-situ data of Sb-ADCP, CTD and satellite images. The findings suggest that a counter-clockwise eddy and a clockwise eddy both are with 0.01 S vortice appears in the wake of Liu Chiu Yu when the background flows are toward the northwest. The system of two eddies with opposite rotation and a central return flow develops an unsteady eddy shedding. On the other hand, when the background flows are toward the southeast, island wake generated in the lee of Liu Chiu Yu is attached system of two eddies with opposite rotation and a central return flow. The Sb-ADCP data shows that the flow pattern in the northeastern coast of Liu Chiu Yu is mainly semidiurnal. The major axis of the ellipse of the semidiurnal current is parallel to the orientation of the coast line (northeast to southwest) and the shape of the ellipse is quite long and narrow. The amplitude of the semidiurnal current is approximately two times that of the diurnal current. Generally, the currents are stronger and the occurring probability of the island wake is higher during spring tide. The CTD data shows that the eddy center appears to be divergent and upwelling occurs in the areas under the influence of island wakes. The upwelling pumps deep seawater to the surface and results in low temperature, high salinity, high oxygen concentration and low chlorophyll concentration. On the other hand, in the eddy edges, downwelling occur causing high temperature, low salinity, low oxygen concentration and high chlorophyll concentration. Strong shear was formed at the depth of 60m inside the island wake which generates thermocline so that the mixing phenomenon is quite obvious there. Moreover, in the regions without the influence of island wakes, the stratifying effect is clear and the horizontal variation of temperature, salinity and oxygen concentration is small. Therefore, neither upwelling nor downwelling occurs there. Furthermore, along the edge between blocking and free-stream areas, the shear stress increases and the mixing phenomenon arises to a certain degree. The satellite images show that an island wake appears in the southeastern Liu Chiu Yu during spring tide. The island wake develops a phenomenon called von Karman vortex street. At the same time, a counter-clockwise eddy with heavy suspensions appears in the northern Liu Chiu Yu. The radius of the eddy is around 4 Km. The area of the lowest chlorophyll concentration is located at the center of the eddy. By analyzing all these data, it is concluded that the island wake in Liu Chiu Yu usually appears during spring tide.