農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

本研究之主要目的旨在探討東沙島西部小範圍之陸坡漁場魚種群社組成。1995 年 4 月18 至 19 日調查期間，於 20o 20' N–20o 40' N，115o 30' E–115o 50' E，水深 400至 450 公尺之海域，實施 6 網次底拖網漁撈試驗。魚類及蝦類之線性生物量分別大於20.0 及大於 5.0 且於兩測站以上同時出現者，魚類計有 8 種，佔魚類總漁獲量的 83.5%；蝦類 3 種，佔蝦類總漁獲量的 94.7%。各測站之夏農‧魏能 (Shannon-Wiener) 歧異度指數與各測站間之差異不顯著。群社分析結果顯示，主要魚種與蝦類組成均可區分為 2 組群社。依魚種別之對數線性生物量可將所調查測站群社區分為 1 組；依蝦種別分析所獲得之測站群社組數亦同。

The main purpose of this study was to understand thecharacteristics of demersal fish assemblages in the area near westTung-Sha Tao, South China Sea, with six bottom trawl operations alonga transect at depths of 400-450 meters during 18-19 April 1995. Atotal of 8 major fish species and 5 prawn species occupying 74.9% and9.7% of the total collected species were recorded respectively. Thespecies found at duplicated stations of which the total linear biomasswere greater than 20.0 for fish and 5.0 for prawn were selected forthe cluster analysis. The relationship between the values ofShannon-Wiener's index and the sampling stations had no significantdifference (p>0.05). Using the unweighted pair group method arithmeticaverage (UPGMA) and the Bray-Curtis dissimilarity values, 6 trawloperation stations were grouped into 1 cluster and 8 fish species and5 prawn species were classified into 2 groups respectively. Based onthe catch percentages and cluster analysis, the study area may beconsidered as one of the major habitats of hairtail Trichiuruslepturus.