Management of Anchored Subsurface Fish Aggregation Devices (FADs) in the Water of the Eastern Taiwan

• Main Authors: Tsung-YiTsai, 蔡宗嶧
• Other Authors: Yi Chang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/54167721515121353182

碩士 === 國立成功大學 === 海洋科技與事務研究所 === 102 === The use of fish aggregation devices (FADs) has increased catch sizes and convenience for fishermen; however, these devices may have a harmful impact on tuna stocks. Such structures are deployed throughout the oceans worldwide to concentrate fish and, thus, facilitate catching them. In addition, FADs may change the migration behavior of fish. Therefore, the use of FADs may influence the population of exploited fish species, leading to concerns of overfishing and decreases in recruitment in capture fisheries. Eight FADs are moored semipermanently on the continental shelf off the coast of eastern Taiwan. These FADs are under the sea surface at a depth of 20–60 m and located less than 30 km from the shore. Fishing data from the Fisheries Research Institute, Council Of Agriculture, Taiwan and Taitung Fishermen’s Association were analyzed to identify the various species caught, the frequency distribution of fork lengths, and catch per unit of effort (CPUE) in waters around FADs. The data revealed that fishing conditions differ between two substudy areas. The dominant species in Area A (near land) were yellowfin tuna, skipjack, and dolphinfish; however, the dominant species in Area B (farther from land) were yellowfin tuna, which represented more than 80% of the catch. The frequency distribution of fork lengths indicated that fish mainly ranged in size from 41 to 50 cm in Area A, but the size of the fish was often greater than 70 cm in Area B. Moreover, the CPUE has decreased in the past decade. In addition, conflict between fishing boats using different fishing gear has increased the need for enhanced management requirements for FADs. Appropriate management strategies for FADs and fish resources, namely limitation of fishing efforts and autonomous management by fishermen organizations, are recommended.