辽河口邻近海域小型底栖生物的r空间分布及季节变化

摘要

本文研究了辽河口邻近海域2013年8月、10月和2014年5月3个航次小型底栖生物的种类及其空间分布,分析了小型底栖生物丰度和生物量的季节变化.结果表明,3个航次(夏季、秋季和春季)小型底栖生物的平均丰度分别为(264±83)ind/(10 cm2)、(216±85)ind/(10 cm2)和(227±67)ind/(10 cm2),平均生物量分别为(272±125)μg/(10 cm2)、(207±89)μg/(10 cm2)和(244±103)μg/(10 cm2).与其他研究海域相比,辽河口小型底栖的丰度和生物量处于较低水平.共鉴定出了14个小型生物类群,按照丰度排序,线虫是最优势的类群,夏季、秋季和春季3个航次占总丰度的比例分别为94.0%、92.5%和90.8%;其他优势类群为多毛类、桡足类和双壳类.小型底栖生物量的优势类群则为多毛类(41.1%~44.0%),高于线虫(33.8%~36.5%),其次是双壳类(2.6%~6.7%).水平分布的研究表明,调查海域近岸入海口小型底栖生物的丰度和生物量普遍低于近海海域,但是秋季时近岸分布与近海差距不大.垂直分布的研究表明,95.9%的小型底栖生物分布于0~5 cm的表层沉积物中.小型底栖生物的丰度和生物量在夏季时都达到高峰值.与环境因子的相关分析表明,小型底栖生物的数量分布与盐度和水深呈极显著正相关(P<0.01),与叶绿素a呈显著正相关(P<0.05).%The benthic meiofauna was quantitatively investigated in the Liaohe Estuary in August (summer)in 2013,October (autumn)in 2013 and May (spring)in 2014,and its spatial distribution and season variation were studied.The mean abundance of the meiofauna in summer,autumn and spring was (264 ±83)ind/(10 cm2 ), (216±85)ind/(10 cm2 )and (227±67)ind/(10 cm2 ),respectively,and the mean biomass was (272±125)μg/(10 cm2 ),(207±89)μg/(10 cm2 )and (244±103)μg/(10 cm2 ),respectively.Compared with other studied are-as,the abundance and biomass of meiofauna in Liaohe Estuary were at a low level.A total of 14 meiofauna groups were identified.Free-living marine nematodes were the most dominant group in abundance,with the dominance of 94%,92.5% and 90.8% in summer,autumn and spring,respectively,followed by polychaetes,benthic cope-pods and bivalves.In terms of biomass,the dominant groups were polychaetes (41.1%-44.0%),nematodes (33.8%-36.5%)and bivalves (2.6%-6.7%).The study of horizontal distribution showed that the abundance and biomass of the benthic meiofauna in inshore water were generally lower than those in offshore water,except autumn.The study of vertical distribution showed that 95.9% of the meiofauna distributed in the top 0-5 cm sed-iment.The abundance and biomass of the benthic meiofauna both reached their peak in summer.The correlation a-nalysis indicated that the abundance of meiobenthos high significantly correlated with depth and salinity (P <0.01),and significantly correlated with Chl a (P <0.05).