基于围隔实验研究虾夷扇贝与龙须菜养殖对浮游植物群落结构的影响

Effects of Culture of Patinopecten yessoensis and Gracilaria lemaneiformis on Phytoplankton Community Structure Based on an Enclosure Experiment

中文关键词: 虾夷扇贝  龙须菜  浮游植物群落结构  围隔实验  桑沟湾

英文关键词: Patinopecten yessoensis  Gracilaria lemaneiformis  Phytoplankton community structure  Enclosure experiment  Sanggou Bay

中文摘要:

      2015年秋季在桑沟湾开展围隔实验，研究了60 h内高容量虾夷扇贝(Patinopecten yessoensis)和龙须菜(Gracilaria lemaneiformis)养殖对水体中物理、化学和生物(浮游植物群落)等因素的影响。结果显示，养殖的虾夷扇贝和龙须菜在60 h内能显著改变水体中的溶解氧(DO)和溶解态无机氮(DIN)的浓度，同时，能显著影响浮游植物种群丰度和组成特征。从各实验组来看，12 h后，虾夷扇贝和龙须菜实验组浮游植物丰度显著低于空白实验组。虾夷扇贝对水体中4种硅藻优势种[包括柔弱拟菱形藻(Pseudo-nitzschia delicatissima)、双菱藻(Surirella sp.)、菱形藻(Nitzschia spp.)、针杆藻(Synedra spp.)]的滤除效应存在较大差异，即对柔弱拟菱形藻和双菱藻有较大的滤除效应，但对菱形藻和针杆藻却影响不大。基于水体中的光合色素变化特征也揭示了虾夷扇贝对浮游植物的选择性摄食效应，即虾夷扇贝能显著滤除水体中的岩藻黄素(fucoxanthin，硅藻特征色素)、别藻黄素(alloxanthin，隐藻特征色素)。与此相反，青绿藻素(prasinoxanthin，微微型藻类的特征色素)在48 h后，虾夷扇贝实验组显著高于空白实验组和大型藻实验组，说明龙须菜养殖对微微型青绿藻生物量无显著影响。

英文摘要:

      Enclosure experiments were carried out in Sanggou Bay in autumn 2015 to study the effects of high-capacity Patinopecten yessoensis and Gracilaria lemaneiformis culture on physical, chemical, and biological (phytoplankton community) factors of aquatic water within 60 h. The results showed that the concentration of dissolved oxygen (DO) and dissolved inorganic nitrogen (DIN) in water, and the abundance and composition of phytoplankton population can significantly change within 60 h. After 12 h, phytoplankton abundances in the experimental groups of P. yessoensis and G. lemaneiformis were significantly lower than that in the control groups. The filter effects of P. yessoensis on four dominant diatom species (Nseudo-nitzschia delicatissima, Surirella sp., Nitzschia spp., and Synedra spp.) in aquatic water were significantly different, indicating a greater filter effect on P. delicatissima and Surirella sp., than that on Nitzschia spp. and Synedra spp.. The characteristics of photosynthetic pigments in water also revealed the selective feeding effect of P. yessoensis on phytoplankton; that is, P. yessoensis could significantly filter fucoxanthin (characteristic pigment of diatoms) and alloxanthin (characteristic pigment of Cryptphytes) in water. On the contrary, prasinoxanthin (the characteristic pigment of pico-algae) was significantly higher in the scallop groups than in the control groups and the macroalgae groups after 48 h, which indicated that the cultivation of G. lemaneiformis had no significant effect on the biomass of pico-algae.