摘要：
Based on data from benthic trawling in Daya Bay between 2004 and 2015,the temporal and spatial characteristics of species composition and diversity were analyzed.A total of 429 species of marine animals were identified,belonging to 10 phyla,16 classes,175 families,and 309 genera.Species numbers varied between 75-114 in Daya Bay between 2004 and 2015.Chordata,Arthropoda,and Mollusca were the dominant phyla from 2004 to 2015,respectively.Species numbers showed a decreasing trend from 2004 to 2015.In the spring,the species number was higher in the western part of Daya Bay than the eastern region before 2007.More recently,the species number was higher in the mouth and the eastern parts of Daya Bay than the northern and western regions.In the summer,the species numbers increased in the southwestern region of the bay before 2008,but after 2009 results showed that the species number was higher in the mouth of the bay than the inner region.Timoclea imbricata or Paphia undulata were the first dominant species in spring.In summer,the first dominant species varied before 2007,but Turritella bacillum was the most dominant species after 2008.In autumn,Timoclea imbricata or Turritella bacillum was the first dominant species.The average Shannon-Wiener diversity index (H'),Pielou's evenness index (J),and species richness index (d) varied between 1.46-4.05,0.30-0.89 and 2.49-6.69,respectively.Diversity decreased in Daya Bay between 2004 and 2015,especially in the northwestern area,mainly due to heavy anthropogenic activities.In recent years,the species resources of some areas of Daya Bay contribute mostly to the function of species diversity of the whole bay in the past,and benthic ecosystems have become more fragile.%为了能够掌握大亚湾物种多样性状况,本文利用2004-2015年大亚湾底栖生物调查底拖网数据,研究了该海域的生物种类组成、优势种及物种多样性的时空变化.结果表明:2004-2015年共获得海洋动物429种,隶属于10门16纲175科309属,各航次物种数变化范围在75-114种之间,不同年份、季节均以软体动物、节肢动物和鱼类为主要生物类群;大亚湾物种数量的空间分布存在差异,春季在2007年前基本呈现海湾西部高于东部的趋势,夏季在2008年前则呈现向海湾西南部升高的趋势,之后不同季节则基本呈现湾口高于湾内北部、东部高于西部的趋势;大亚湾的主要优势种具有一定的季节性变化,春季常以鳞片帝汶蛤(Timoclea imbricata)或波纹巴非蛤(Paratapes undulatus)优势度最高,夏季2004-2007年间优势度最高的优势种经常变化,2008年后则以棒锥螺(Turritella bacillum)优势度最高,秋季棒锥螺或鳞片帝汶蛤优势度最高;2004年后大亚湾底拖网物种多样性呈逐渐降低的趋势,特别是海湾北部物种多样性下降严重,受人类活动的干扰较大.目前,大亚湾的局部区域承担了整个海湾物种多样性的维持功能,底栖生态系统相对更加脆弱.
