海州湾海洋牧场沉积物-水界面营养盐交换通量的研究

为研究海洋沉积物-水界面间营养盐的交换状况,进一步了解营养物质的循环动力学和水体富营养化的内在机理,采用实验室培养法,对海州湾海洋牧场2014年春季(5月)5个站位、夏季(8月)6个站位和秋季(10月)6个站位沉积物-水界面营养盐的交换速率和交换通量进行了研究。结果表明:海州湾沉积物-水界面上硅酸盐(Si O2-3-Si)、磷酸盐(PO_4~(3-)-P)在春季表现为由水体向沉积物进行迁移,其交换速率平均值分别为-3.27、-0.32 mmol/(m~2·d),夏季和秋季均表现为由沉积物向水体进行释放,夏季二者的交换速率平均值分别为8.53、0.41 mmol/(m~2·d),秋季分别为4.92、0.32 mmol/(m~2·d);溶解态无机氮(DIN)在春、夏、秋季均表现为由沉积物向水体进行释放,交换速率平均值分别为2.86、3.39、13.04 mmol/(m~2·d);海州湾沉积物-水界面SiO_2-3-Si、PO_4~(3-)-P、DIN的交换通量在3个季节的平均值分别为4.56×10~8、1.82×10~7、8.65×10~8mmol/d,沉积物可为海州湾初级生产力提供66%的SiO_2-3-Si、42%的PO_4~(3-)-P、124%的DIN营养供给。研究表明,海州湾海洋牧场沉积物-水界面营养盐的交换速率与国内外近岸海区相比处于中等水平。

Exchange fluxes of nutrients at sediment-seawater interface in marine ranching area of Haizhou Bay

The exchange rates and fluxes of nutrients on sediment-water interface were studied in Haizhou Bay u-sing a laboratory incubation method during spring ( May;5 stations) , summer ( August;6 stations) and autumn ( October;6 stations) in 2014 to understand the exchange of nutrients on sediment-water interface and mechanisms of nutrient cycling and eutrophication. The results showed that SiO2-3 -Si and PO3-4 -P ions were fund to migrate from water to sediments at sediment-water interface in Haizhou Bay in Spring, with average rates of -3. 27 and -0. 32 mmol/(m2·d);while they were released into the water in summer and autumn, with average rates of 8. 53 and 0.41 mmol/(m2·d) in summer and 4. 92 and 0. 32 mmol/(m2·d) in autumn. Dissolved inorganic nitrogen (DIN) was released into the water in three seasons, with average exchange rates of 2. 86 mmol/(m2 ·d) in spring, 3. 39 mmol/(m2·d) in summer and 13. 04 mmol/(m2·d) in autumn. Exchange rates of nutrients inclu-ding SiO2-3 -Si, PO3-4 -P and DIN at sediment-water interface in Haizhou Bay were in a medium level compared to domestic and foreign coastal waters in three seasons, with average exchange fluxes of 4. 56×108 mmol/d for SiO2-3 -Si, 1. 82×107 mmol/d for PO3-4 -P, and 8. 65×108 mmol/d for DIN. The nutrients from the sediment provided 66%of SiO2-3 -Si, 42% of PO3-4 -P and 124% of DIN for primary productivity in Haizhou Bay.