南黄海浒苔绿潮暴发区氨基酸时空分布特征

根据南黄海绿潮发展过程将浒苔绿潮区分为35°N以南和35°N以北2个区域，并利用2018年南黄海海域春、夏季2个航次的调查数据研究分析了浒苔绿潮发生前后2个区域总溶解氨基酸（TDAA）、溶解游离氨基酸（DFAA）的分布特征及变化规律.结果表明，TDAA和DFAA的浓度均基本呈现近岸高远岸底的水平分布特点，35°N以南海域夏季相对于春季水体TDAA、DFAA的浓度整体呈现上升趋势，其中TDAA浓度升高程度明显，表、中层TDAA浓度分别升高了24.8%、60.6%，而35°N以北海域水体中TDAA的浓度却降低了8.7%，其中表层水体TDAA含量下降了30.1%.在DIN浓度较低的35°N以北海域，浒苔的吸收利用可能是造成该区域表层水体TDAA含量降低的重要原因.由此可见，35°N以北海域水体氨基酸等小分子有机氮对浒苔绿潮后期的维持发展起着重要的支持作用.

Temporal and spatial distribution characteristics of amino acids in the green tide outbreak area of Ulva prolifera in the South Yellow Sea

According to the distinct growth phases of green tides, the green tides development area of Ulva prolifera was divided into two regions: south of 35°N and north of 35°N. The survey data of the South Yellow Sea in two cruises in the spring and summer of 2018 were used to analyze the spatial-temporal distribution characteristics of total dissolved amino acids (TDAA) and dissolved free amino acids (DFAA) in these two regions. The results revealed that concentrations of TDAA and DFAA showed a decreasing distribution from inshore (high) to offshore (low). In the area south of 35°N, the TDAA concentrations increased from spring to summer by 24.8% in the surface seawater and 60.6% in the middle layer seawater, respectively. However, in the area north of 35°N, the TDAA concentration was decreased by 8.7% overall, and decreased by 30.1% in the surface seawater. The uptake and utilization of DON by Ulva prolifera might be an important reason for the TDAA concentration decrease in the seawater with low DIN concentration in the area north of 35°N, which suggested that small molecular organic nitrogen, such as amino acids, played a key role in the late-stage green tide development of Ulva prolifera.