摘要
Abstract
Based on the fishery data of four oceanographic censuses in the Dongshan Bay from 2012 to 2013 , the composition characteristics of fish eggs, larvae and juveniles, nekton were preliminarily analyzed. Results indicated that 15 species of fish eggs, 8 species of larvae and juveniles were identified, including 5 indeter-minate species of larvae and juveniles. For fish eggs, larvae and juveniles, the average densities were 2. 63 ind/m3 and 0. 50 ind/m3. 269 nekton species were recorded, including 202 fishes, which was the largest populations in number. In seasonal distribution, nekton species was the most ( 161 ) in summer, while the least (62) in winter. From the plane distribution, the most species (95) was in no. fifth station and the least species (12) was in no. ninth station in summer. For mean weight density of nekton, the greatest was 1 246. 98 kg/km2 in winter and the minimal was 372. 68 kg/km2 in spring. While for mean individual density of nekton, the highest was 36. 04 × 103 ind/km2 and the lowest was 11. 25 × 103 ind/km2. Dominant species of four seasons varied, which showed the obvious phenomenon. For nekton’s weight density, the order of diver-sity index was autumn>summer>spring>winter, species richness index d, evenness index J’ and pure in-dex C were 3. 49, 0. 64 and 0. 23. For nekton's individual density, the order of diversity index was summer>spring>autumn >winter, species richness d, evenness index J’ and pure index C were 7. 09, 0. 70 and 0. 18, separately. Compared with the historical data, the mean densities of fish eggs, larvae and juveniles, nekton were higher, and the species and species diversity of nekton were rising in this investigation.关键词
东山湾/渔业资源/种类组成/数量分布Key words
Dongshan Bay/fishery resources/species composition/quantity distribution分类
农业科技
