Analysis of community structure and diversity of nekton in Kaozhouyang Bay using gill nets and cages
摘要: 为准确了解考洲洋的渔业资源状况，文章基于2017年11月至2018年7月4个季节对考洲洋的刺网、地笼调查数据，对目前考洲洋的游泳生物群落结构、多样性进行了分析。调查中共捕获经济物种93种，其中鱼类11目33科61种，占总物种数的64.52%；甲壳类2目6科33种，占总物种数的35.48%。鱼类以鲈形目(45.16%)和鲱形目(7.52%)居多，且绝大部分(96.7%)为暖水种。各季节渔获量变化明显，夏季最高，其次是春、秋、冬季，但四季的大部分个体体质量都在0~8 g和8~64 g 2个区间内。考洲洋的多样性指数值波动较大，物种丰富度 (D)为0.81~3.63，Shannon-Wiener指数(H′)为0.81~2.03，均匀度指数 (J′)为0.55~1.69。但方差分析结果显示，不同季节、站点间的D、H′、J′均无显著性差异。结果表明考洲洋总体资源量较低，多样性水平季节变化较大，湾内资源空间分布较为均匀。Abstract: To better understand the status of fishery resource of Kaozhouyang Bay, we have conducted a seasonal investigation of the community structure and diversity of the nekton by using gill nets and cages net from November 2017 to July 2018. A total of 93 economic species were collected, and among them 61 were fish belonging to 11 orders and 33 families, accounting for 64.52% of the total species number, and the rest were crustaceans. Perciformes (45.16%) and Clupeiformes (7.52%) which were mostly warm water species were the two largest orders of fish. The catches had significant seasonal variation (summer>spring>autumn>winter), and mostly fell in two intervals of 0−8 g and 8−64 g. The diversity indices in Kaozhouyang Bay showed obvious variation. The species richness index was 0.81−3.63; the Shannon-Wiener index was 0.81−2.03; the evenness index was 0.55−1.69. No significant difference was found in the richness index, Shannon-Wiener index and evenness index among different seasons and stations. In conclusion, the total fishery resources in Kaozhouyang Bay are relatively small. The biodiversity shows obvious seasonal variation, while the spatial variation is insignificant.
表 1 考洲洋四季各站点环境因子
Table 1. Hydrological environmental variables in Kaozhouyang Bay during four seasons
S1 2.00 24.3 28.7 8.1 S2 1.96 24.6 28.5 8.0 S3 1.41 24.5 22.1 8.0 S4 1.60 24.0 19.1 8.2 S5 1.20 23.9 19.9 7.9 冬季
S1 0.90 17.1 26.6 6.9 S2 1.35 16.5 24.5 6.8 S3 1.17 15.5 20.6 6.9 S4 1.22 17.0 24.1 6.9 S5 0.76 14.9