烟台四十里湾海域营养盐和沉积物-水界面交换通量

利用2009年5月、7月、10月和2010年1月4个航次对烟台四十里湾养殖海域的调查资料,分析了该海域营养盐分布、季节变化、主要控制过程以及沉积物-水界面交换通量。结果表明,四十里湾海域营养盐的分布整体趋势是近岸高,由近岸向外部海域递减;受到陆源输入的影响,高值区出现在调查海域东部。DIN的季节变化表现出冬高、秋低、春夏居中的趋势,整体上变化不大;SiO3-Si和PO4-P浓度均为春季最低。在春秋季P为四十里湾浮游植物生长的限制性因素,在夏季,N/P>30,P也是一个潜在的限制因素。四个季度培养结果表明DIN总体上由上覆水交换到沉积物中;近岸区沉积物是PO4-P的汇;调查区域SiO3-Si的扩散方向均是从沉积物到上覆水中。四十里湾沉积物释放的SiO3-Si对初级生产力的贡献较小;与其他浅海环境相比,四十里湾沉积物-水界面的营养盐通量处于较低水平。

Distribution features of nutrients and flux between the sediment and water interface in Sishili Bay

Four cruises were conducted in Sishili Bay in May,July,October of 2009 and January of 2010 to discuss nutrient distribution,seasonal variation,primary control processes and exchange fluxes between the sediment and water interface.The results indicated that nutrients were high in the coastal area and low in the open sea.The high value occurred mainly in the eastern regions of Sishili Bay.The concentration of DIN was the lowest in autumn,while the concentrations of SiO3-Si and PO4-P showed the lowest in winter.Based on the analysis of nutrient limiting criterion and the lowest threshold values of phytoplankton growth,P was the limiting factor for phytoplankton growth in spring and autumn in Sishili Bay,P was also a potential limiting factor in summer.The DIN and PO4-P showed a net exchange flux from water to sediment,while SiO3-Si were released from sediment to seawater.It showed that the contributions of SiO3-Si fluxes released from the sediment to primary production was quite limited.Comparing to other shallow sea environments,the benthic nutrient fluxes in Sishili Bay were ranked in the lower level.