碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 105 / The set net fishery is one of the important coastal fisheries of Taiwan. It is the important method for the observation of coastal fisheries resource structure, as this method was usually used to sampling the biological resources migrating to the coastal waters. This study was tried to collect the daily catches data of Fu-Xing set net fishing grounds from March 2011 to February 2015 in the waters of Shih-cheng, Yilan county. The average catch per unit effort (CPUE) by years and seasons was calculated to analyze the fishery resources structure. The community diversity analysis and the relative importance index were used to evaluate the characteristic and changes in the structure of marine resources in this area.
The results showed that the annual operational days of Fu-Xing set net fishing grounds were varied about 240 to 284 days, and the average annual CPUEs were fluctuated between 728 ~ 1288 kg/day. In addition, the main fishing season with the highest CPUE of 1619 kg/day is in spring, while the slack winter season with the lowest CPUE of 388 kg/day is from December to next February every year. Based on the catch data of species larger than 1% of total catches, the major three dominant species were changed by year. For example, the dominant species are Katsuwonus pelamis (55.74%) in year 2011, while the dominant species were changed to Katsuwonus pelamis (31.91%), Katsuwonus pelamis(32.89%), and Katsuwonus pelamis(40.42%) in years of 2012 to 2014, respectively.
It is interesting that the lowest diversity index, species richness index, evenness index and diversity index were happened in summer, and then those indexes began to subsequently increase till winter. In addition, species richness index varied between 1.35 to 1.47, while the divergence index and evenness index were reach to the lowest and the highest value in 2011 and 2014, respectively.
Furthermore, the high variation of alternative species was happened in season of spring and autumn, but lower in summer and winter. Refer to migration index (MI), it showed the most stable communities were appeared in winter, while spring and autumn were the key seasons for maximum and minimum species, respectively. Comparing the species similarity in seasons between different years, the lowest species similarity in 2014 was different to the other three years. For the similarity of the year in each season, the most similar species of four seasons was appeared in 2013, and, overall, the species similarity between the autumn and winter were lower than those between spring and summer. For the yearly comparison, species similarity was highest (77%) in 2011 & 2013, and lowest (56%) in 2012 & 2014. Finally, the influence of Typhoon on catch and diversity was also discussed in this study.
| Identifer | oai:union.ndltd.org:TW/105NTOU5451006 |
| Date | January 2017 |
| Creators | Hsieh, Yu-Hua, 謝侑樺 |
| Contributors | Lee, Ming-An, 李明安 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 52 |
Page generated in 0.0019 seconds