陆基推水集装箱循环水养殖系统中浮游植物群落结构特征

Characteristics of the phytoplankton community in a land-based container aquaculture system with recycling water

为研究陆基推水集装箱循环水养殖模式中养殖水体及净化系统浮游植物群落结构特征,于2021年10月对集装箱养殖中华鲟(Acipenser sinensis)水体与净化处理系统水体中的浮游植物及水质理化因子进行分析,并运用多样性指数、均匀度指数等评价养殖水体与净化水体的浮游植物群落结构特征。结果显示:在养殖水体内共鉴定出浮游植物4门17属21种,在净化系统水体中共鉴定出8门51属93种,净化系统水体内浮游植物种类数显著大于养殖水体的(r=0.918,P<0.01)。在养殖水体中,浮游植物丰度与生物量分别为2.816×10^(5)cells·L^(-1)和0.021 mg·L^(-1),优势种主要为类颤鱼腥藻(Anabaena oscillarioides)和颗粒直链藻极狭变种(Melosira granulate var.angustissima);在净化系统水体中,浮游植物丰度与生物量平均值分别为1.135×10^(6)cells·L^(-1)和0.763 mg·L^(-1),优势种为被甲栅藻(Scenedesmus armatus)、二形栅藻(Scenedesmus dimorphus)、顶锥十字藻(Crucigenia apiculata)、尖针杆藻(Synedra acus)、细小平裂藻(Merismopedia minima)等;净化系统水体浮游植物丰度与生物量显著高于养殖水体的(P<0.01),且优势种种类较多。净化系统水体浮游植物的多样性指数、均匀度指数等均显著高于养殖水体的(P<0.05),Shannon-Wiener多样性指数与Pielou均匀度指数显示养殖水体为β-中污染水平,净化系统水体为轻污染水平。冗余分析(RDA)结果显示,影响集装箱循环水养殖水体与净化系统水体浮游植物群落的主要理化因子为pH、比电导率(SPC)、溶解氧(DO)与NO_(3)^(-)-N等,净化系统水体浮游植物群落主要与NO_(3)^(-)-N、NO_(2)^(-)-N、光照等因子有关。研究表明,在实际生产中可通过调控水质条件控制集装箱循环水养殖系统与净化系统水体中浮游植物群落结构来维护养殖模式的良好运行。

To explore the phytoplankton community characteristics in a land-based container aquaculture system with recycling water and purification system,we analyzed the phytoplankton community and water physicochemical factors in the culture water of an Acipenser sinensis aquaculture container and ecological purification system.Then,we applied Shannon-Wiener diversity index and Pielou evenness index to evaluate the phytoplankton community characteristics.The experiments were carried out in October 2021 at Taihe County,Fuyang City,Anhui Province.The results showed that a total of 21 species(17 genera,4 phyla)of phytoplankton were detected in the culture water,while 93 species were identified in the purification system,belonging to 8 phyla and 51 genera.The number of phytoplankton species in the purification system was significantly higher than that in the culture water of the land-based container with a recycling water aquaculture mode(r=0.918,P<0.01).In the culture water,the phytoplankton density and biomass were 2.816×10^(5)cells·L^(-1)and 0.021 mg·L^(-1),respectively,and the dominant species were Anabaena oscillarioides and Melosira granulate var.angustissima.In the purification system,the phytoplankton density and biomass were 1.135×10^(6)cells·L^(-1)and 0.763 mg·L^(-1),respectively,with the dominant species being Scenedesmus armatus,Scenedesmus dimorphus,Crucigenia apiculate,Synedra acus,and Merismopedia minima.The purification system had more dominant species of phytoplankton,and the phytoplankton density and biomass were significantly higher than that in culture water(P<0.01).The purification system had a higher diversity index and evenness index than the culture system(P<0.05),and the water quality was lightly polluted,while the culture system had aβsecondary pollution level.Redundancy analysis(RDA)of phytoplankton abundance,biomass,and water environmental factors showed that pH,specific conductance,dissolved oxygen,and NO_(3)^(-)-N were the main environmental factors affecting the cultural water and purification system,while NO_(3)^(-)-N,NO_(2)^(-)-N,and light were the major environmental factors affecting the purification system.Therefore,in actual production,the phytoplankton community structure in land-based container culture water and the purification system can be controlled by regulating water quality to maintain the operation of the aquaculture mode.