气候变化对海洋渔业资源的影响

根据2014—2015年4个季节南海北部近海底拖调查数据，采用相对重要性指数(index of relative importance，IRI)、Margalef丰富度指数(D)、Shannon多样性指数(H')和Pielou均匀度指数(J')分析当前该海域的渔业资源群落组成和多样性，以了解群落结构动态。全海域共渔获574种游泳生物，以鱼类占比为最高，超过81%。IRI指数结果表明优势种是发光鲷(Acropoma japonicum)、二长棘犁齿鲷(Evynnis cardinalis)、竹䇲鱼(Trachurus japonicus)和蓝圆鲹(Decapterus maruadsi)，而发光鲷是唯一的四季共同优势种，传统经济鱼类比重降低。从多样性指数的时间分布上看，D存在明显的季节变化，呈现夏低秋高的特点；然而H'和J'均未表现季节性。从空间分布看，D高值区主要位于40 m以浅水区，而H'和J'分布格局类似，呈现均质的格局。受禁渔期和捕捞活动的影响，多样性指数在秋季时期最为稳定，而冬季波动最大。

Global imprint of climate change on marine life

Based on the bottom trawl survey data for four seasons during 2014−2015, we analyzed the community composition and diversity of fishery resources by studying index of relative importance (IRI), Margalef richness index D, Shannon diversity index H' and Pielou evenness index J', so as to understand the dynamics of community structure. Altogether 574 species had been caught in this region, among which Fish had the largest proportion with over 81%. The IRI result found four dominant species: Acropoma japonicum, Evynnis cardinalis, Trachurus japonicus and Decapterus maruadsi. A.japonicum was the only common dominant species for four seasons and the proportion of traditional commercial fish decreased greatly. For temporal distribution of diversity indices, there was significant seasonal variation for D indiex (highest in autumn but lowest in summer), while no seasonal variation was observed for H' and J'. For spatial distribution, high value of D index was mainly in shallow water with depth less than 40 m, similar for H' and J'. Due to the effect of closed fishing and fishing activities, the diversity indices fluctuated sharply during winter but smallest in autumn.