| Summary: | 碩士 === 國立高雄海洋科技大學 === 漁業生產與管理研究所 === 101 === In this study, we analyzed the compositions of trash fish caught by small trawlers of Ke-zi-liao fishing port, Kaohsiung City. Between June 2011 and December 2012, catches were sampled at the fishing port on the first ten days, next ten-days and the last ten-days of every month. Then, we recorded the total number of trash fish caught in a day, and analyzed changes in composition and quantity of the dominant species. In addition, we collected landing data for the fish market auction from Tzu-Guan Fisher’s Association and analyzed changes in the total catch by the trawlers.
The results of this study showed the catches of the trawlers was mainly composed of 83.78% fish, 4.64% crabs, and 11.57% cephalopods. The percentage of trash fish, crabs, and cephalopods was 85.86%, 11.39%, and 2.75%, respectively. The largest amount of trash fish caught was about 187 tons in a month, while the minimum amount was about 15 tons. The average amount of trash fish in Ke-zi-liao fishing port was estimated to be about 948 tons per year. Analysis of seasonal variations showed that the amount of trash fish was higher in autumn and winter, and lower in spring and summer. A total of 217 species, 60 crab species, and 6 cephalopod species were found in this study. The biodiversity index indicated that the diversity of trash fish was higher in spring and summer. We compared the lengths of economically fish and found that, most fishes, such as Trichiurus lepturus, Trachinocephalus myops, Gymnothorax reticularis, and Parapercis sexfasciata, were caught in the juvenile stage, except Benthosema pterotum and Metapenaeopsis provocatoria longirostris. These results show that the structure of the marine ecosystem would be affected if large amounts of trash fish are caught
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