平潭海域夜光藻对几种饵料藻的利用与生长

Different growth of red Noctiluca scintillans from Pingtan coast waters feeding on several diet algae

夜光藻(Noctiluca scintillans)藻华是我国近海常见的生态灾害,其暴发机制尚不明确。为探究营养条件在其形成机制中的作用,本文分析了几种常见饵料藻与同海域硅藻培养下夜光藻的种群增长,同时探究模拟海水混合与营养盐水平对其种群增长的影响。结果发现,不同饵料藻培养下,夜光藻种群增长有着显著差异,其中亚心形扁藻(Platymonas subcordiformis)组中夜光藻的平均增长率为(0.151±0.001)d,远高于其他饵料藻。海水混合对夜光藻种群增长有一定的促进作用,模拟海水混合时,部分实验组中夜光藻增长率显著高于静置实验组,其中微小海链藻(Thalassiosira minima)培养下的夜光藻种群增长率为(0.136±0.001)d,远高于除亚心形扁藻以外的其他实验组。随着营养盐水平的增加,与亚心形扁藻共培养的夜光藻种群增长出现明显的先增强后减弱的趋势,拟合结果表明,其种群增长符合Boltzmann模型,并与营养盐水平相关。结果表明,海水混合与营养盐输入引起的平潭海域微藻的快速繁殖在当地夜光藻藻华的形成机制中可能起着重要的作用。

Blooms of red Noctiluca scintillans is an annual eco-disaster in coastal waters of China,but the mechanism of outbreak of N.scintillans is still unclear.To explore the role of nutrient conditions in the formation of N.scintillans blooms,the population growth of N.scintillans feeding several diet algae,including common diet algae and local diatoms,were investigated under standing water,mixing water and different inorganic nutrient levels.Results showed that there were significant differences in population growth of N.scintillans under different diets.Population growth of N.scintillans was fastest in Platymonas subcordiformis treatment,with growth rate of(0.151±0.001)d.N.scintillans growth significantly increased in mixing water when feeding on some diet algae.The population growth rate of N.scintillans in Thalassiosira minima treatment was(0.136±0.001)d,which was much higher than growth rate of N.scintillans in other algae treatment except in P.subcordiformis treatment.Growth rate and maximum population of N.scintillans cultured with P.subcordiformis firstly increased and then decreased with increasing inorganic nutrient levels,and results suggested that its growth fitted the Boltzmann model,with parameters were highly related to inorganic nutrients.Results indicated that proliferation of local diet algae,such as Thalassiosira species,leading by nutrients input in spring,combined with mixing of seawater,might play an important role in the formation of massive N.scintillans bloom in Pingtan coastal waters.