中文摘要：

2015年7月底,在平潭岛中国鲎（Tachypleus tridentatus）保护区沙质潮间带进行了大型底栖动物调查。结果表明,在山岐澳和坛南湾沙质潮间带未发现鲎的幼体和成体,证实中国鲎在山岐澳和坛南湾已经面临濒危的境况。山岐澳潮间带的大型底栖动物物种数、物种多样性指数（H＇）、均匀度指数（J）和丰度指数（d）均高于坛南湾潮间带的大型底栖动物物种数、物种多样性指数、均匀度指数和丰度指数,而山岐澳潮间带的大型底栖动物栖息密度和生物量低于坛南湾潮间带的大型底栖动物栖息密度和生物量。两个海湾大型底栖动物群落的差异与肋虫昌螺（Umbonium costatum）分布有关,坛南湾潮间带栖息着高密度的肋虫昌螺,而在山岐澳潮间带肋虫昌螺很少。AZTI’s海洋生物指数（AMBI）和多变量海洋底栖生物指数（M-AMBI）值证实山歧澳和坛南湾沙质潮间带生态环境均属于受轻度扰动状态。山岐澳主要受海水养殖的影响,吊养的生物和浮筒减缓了水动力,导致山岐澳潮间带低洼区表层为泥质沉积物。坛南湾是旅游区,潮间带受人为踩踏较多。

英文摘要：

At the end of July 2015,the benthic macrofauna were investigated in sandy intertidal zone in Chinese Horseshoe Crab Reserve in Pingtan island. The results showed that both the larvae and adult of Chinese horseshoe crab were not found in sandy intertidal zone in Shanqi bay and Tannan bay. It was confirmed that Tachypleus tridentatus stayed in an endangered situation in the two bays. The species number,species diversity index（ H＇）,evenness index（ J） and abundance index（ d） of benthic macrofauna in Shanqi bay were all higher than those in Tannan bay,while the density and biomass of benthic macrofauna in the intertidal zone of Shanqi bay were lower than those in Tannan bay. The difference of benthic macrofaunal community between Shanqi bay and Tannan bay was related to the distribution of Umbonium costatum. The density of Umbonium costatum was high in Tannan bay,but it was few in Shanqi bay. The values of AZTI＇s Marine Biotic Index（ AMBI） and Multivariate Marine Benthic Index（ M-AMBI） showed that the ecological and environmental status both in Shanqi bay and Tannan bay were slightly disturbed. The mariculture was the key factor in Shanqi bay,because the suspending aquatic organisms and floats retarded hydrodynamic force led to muddy sediment in lower intertidal zone in Shanqi bay. Tannan bay is a tourism region,where has more artificial tread than Shanqi bay.