秦皇岛海域褐潮暴发区中溶解氨基酸分布特征及季节变化

Spatial Distributions and Seasonal Variations of Dissolved Amino Acids in the Coastal Waters of Qinhuangdao During Brown Tide

通过现场调查,对秦皇岛海域抑食金球藻褐潮暴发区的溶解氨基酸的含量、水平分布、季节变化、组成特征以及与理化因子之间的相关性进行了研究。结果表明:该海区含有较高浓度的溶解结合态氨基酸(DCAA),平均浓度为3.02μmol/L,是总溶解氨基酸(DTAA)的主要组成部分,约占DTAA含量的85%;而溶解游离态氨基酸(DFAA)的含量较低,平均浓度为0.52μmol/L。DCAA和DFAA均有明显的季节变化趋势:3—6月有所升高,7月份明显下降,12月又有所回升。对氨基酸和理化因子的相关性进行分析可知,海水中溶解氨基酸与尿素呈显著正相关(p<0.01)。海水中DFAA的个体氨基酸组成以及酸性氨基酸和碱性氨基酸含量的相对大小存在季节差异,这可能与不同种类氨基酸的来源、保存以及抑食金球藻(Aureococcus anophagefferens)对其利用能力不同有关。

Based on field investigations,the concentrations,horizontal distribution,seasonal variations,composition of dissolved amino acids in the coastal waters of Qinhuangdao during brown tide caused by Aureococcus anophagefferens were analyzed.The correlation between the dissolved amino acids and physical-chemical factors was also studied.The results showed that the average concentrations of dissolved free amino acids（DFAA）and dissolved combined amino acids（DCAA）were 0.52μmol/L and 3.02μmol/L,respectively.DCAA was a main component of total dissolved amino acids（DTAA）,accounting for 85% approximately.The concentrations of DCAA and DFAA showed a significant seasonal difference in the study area,increasing from March to June,decreasing obviously in July,rising again in December.The area with high cell density of Aureococcus anophagefferens were in the south waters of Qinhuangdao and migrated from south to north during the whole process of brown tide.The concentrations of DFAA decreased firstly,and then DCAA concentrations also decreased in the area concentrated Aureococcus anophagefferens.Significant positive correlation was found between dissolved amino acids and urea（p0.01）.Major constituents of DFAA and specific values of acidic amino acids and basic amino acids had obvious seasonal difference.The reason may be the different source and preservation of dissolved amino acids,as well as their utilization by Aureococcus anophagefferens.