2015年冬季钦州湾浮游动物死体对海洋生态系统的影响

Effects of Zooplankton Carcasses in Qinzhou Bay During Winter 2015 on Marine Ecosystem

关键词:  浮游动物  桡足类  死体  冬季  钦州湾

Key words:  zooplankton  copepods  carcasses  winter  Qinzhou Bay

摘要:

[目的]了解浮游动物死体在广西近海的可能规模及其对海洋生态系统的影响。[方法]于2015年冬季在钦州湾选择6个站位进行垂直拖网,采用中性红染色法区分浮游动物死体,研究冬季钦州湾浮游动物死体的组成、分布及其对丰度、优势度和多样性指数的影响。[结果]调查期间,浮游动物死体的平均丰度为2 252个/m³,占浮游动物总丰度的24.5%。共鉴定浮游动物31种(类),其中出现死体的有15种(类)。在优势种(类)中,除强额孔雀水蚤(Parvocalanus crassirostris)外,其它优势种(类)一旦在某站位发现活体,则其死体出现的概率为100%。死体的出现提高了多样性指数,缩小了多样性指数的空间差异。[结论]冬季钦州湾约有1/4的浮游动物是死体。死体的存在会误导我们对浮游动物丰度和多样性的理解,应该引起重视。

Abstract:

[Objective] This study was conducted to assess the amount of zooplankton carcass in coastal areas of Guangxi and its possible effects on marine ecosystem.[Methods] During winter 2015,vertical trawl was conducted in 6 stations for zooplankton collection in Qinzhou Bay.The neutral red staining method was used to distinguished carcass and living zooplankton in order to uncover the composition and distribution of zooplankton carcass,and their effects on the abundance,dominant degree and diversity index (Shannon-Weaver index).[Results] The zooplankton carcasses contributed 24.5% of total abundance of zooplankton,and reached 2 252 ind./m³ in average during the investigation.A total of 31 species (larvae) was identified in this study,and among them the carcasses were found in 15 species (larvae).Once the live dominant species (larvae) were found in one station,then the appearance of the specific carcass in this station was 100 percent chance except for Parvocalanus crassirostris.Meanwhile the appearance of carcasses increased the diversity index and narrowed the difference of diversity index among stations.[Conclusion] About a quarter of total zooplankton was carcasses in Qinzhou Bay during winter.And the existence of carcasses in the zooplankton samples will mislead our understanding of zooplankton abundance and diversity.Thus,we should pay more attention to zooplankton carcasses.