Studies on the fishing-oceanic conditions of Taiwanese seine fishery in the sorthwastern waters of Taiwan

• Main Authors: Chen, Yun-Ting, 陳韻婷
• Other Authors: Liao, Cheng-Hsin
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/fhn598

碩士 === 國立臺灣海洋大學 === 環境生物與漁業科學學系 === 105 === The present study aimed to explore spatial and temporal characteristics of fishing and oceanic conditions for Taiwanese-seine fisheries in the water off southwestern Taiwan. We collected fishing activity data from logbook as well as environmental data such as sea surface temperature (SST), Chlorophyll-a (Chl-a), sea surface height (SSH), wind speed, and precipitation (Pr) for Taiwanese-seine fishing vessels operating in the water off southwestern between 2012 and 2015. These data were further integrated and analyzed using geographic information system (GIS) and multivariate statistical analysis. The analysis of fishing activity data indicated 9 fish species, including moonfish (Mene maculate), spotted mackerel ( Scomber australasicu), jack mackerel ( Trachurus japonicus), yellowfin tuna ( Thunnus albacares), skipjack (Katsuwonus pelamis), finletted mackerel ( Megalaspis cordyla), round scad ( Decapterus maruadsi), bullet mackerel ( Auxis rochei), and pacific round herring (Etrumeus teres) accounted for the majority of total catch. During the summer season, catch abundance of skipjack and yellowfin tuna were relatively higher. During the winter season, catch abundance of jack mackerel and spotter mackerel were relatively higher. During the spring and autumn season, catch abundance of moonfish was relatively higher. With relatively higher catch abundance, fishing grounds were mainly located in the waters of 118°-121°E and 21°-23°N, 116°-118°E and 21°-23°N, and 118°-120°E and 23°-24°N. Fishing ground remained a north-southward shift from 2012 to 2014 and a east-westward shift in 2015. Principal component analysis (PCA) of catch abundance and environmental data indicated that he catch abundance of skipjack and yellowfin tuna were positively correlated with SST, SSH and Chl-a. The catch abundance of moonfish was positively correlated with SST and SSH. The catch abundance of spotter mackerel was negatively correlated with SST and SSH. The catch abundance of jack mackerel positively. correlated with Pr. Taken together, we have demonstrated that major targeted species and fishing grounds of Taiwanese-seine fisheries in the water off southwestern Taiwan vary spatially and temporally, which is likely associated with different oceanic conditions resulted from environmental changes.