莱州湾扇贝养殖区环境因子与浮游植物的关系

Relationship between Environmental Factors and Phytoplankton in Scallop Culture Area of Laizhou Bay

为探究扇贝养殖区环境因子与浮游植物之间的关系,为扇贝科学养殖和海洋环境保护提供参考,于2020年5—11月份对莱州湾扇贝养殖区9个位点进行水样采集,检测了氮、磷营养盐等环境因子以及浮游植物种类、密度和多样性,并应用典范对应分析(CCA)探讨环境因子对浮游植物优势种的影响。结果显示,养殖区内大多数环境因子符合海水一类和二类水质标准,仅活性磷在5月份超标;共检测出浮游植物5门59种,优势种主要以硅藻门为主;浮游植物密度变化范围为0.96×10^(4)~67.86×10^(4)个/L,在5月份、6月份和9月份较高;多样性指数、均匀度指数和丰富度指数的变化范围分别为0.93~3.23、0.33~0.96和0.74~3.34。总体上莱州湾扇贝养殖区各环境因子均适宜扇贝的养殖,浮游植物群落较为丰富、稳定,水体污染程度为轻污染或无污染,水温、pH和氮磷营养盐是浮游植物生长的主要影响因子。

To explore the relationship between scallop culture area of environmental factors and phytoplankton and to provide a scientific reference for scallop aquaculture and Marine environmental protection, water samples are collected from nine sites in the scallop culture area of Laizhou Bay from May to November 2020, and environmental factors such as nitrogen and phosphorus nutrients as well as phytoplankton species, density and diversity are detected. Canonical correspondence analysis(CCA) is applied to investigate the influence of environmental factors on phytoplankton dominant species. The results show that most environmental factors in the aquaculture area meet the class Ⅰ and class Ⅱ water quality standards, and only the active phosphorus exceeds the standard in May. A total of 59 species in 5 phyla of phytoplankton are detected, and the dominant species are mainly diatoms. The density of phytoplankton ranges from 0.96×10^(4) to 67.86×10^(4) cell/L, which is relatively high in May, June and September. The variation ranges of diversity index, evenness index and richness index are 0.93-3.23, 0.33-0.96 and 0.74-3.34, respectively. In general, all environmental factors in Laizhou Bay scallop culture area are suitable for the cultivation of scallops. The phytoplankton community is rich and stable, and the degree of water pollution is light or non-polluting. Water temperature, pH and nitrogen and phosphorus nutrients are the main influencing factors for the growth of phytoplankton.