HgCl_2对网箱养殖海域营养盐在沉积物——水界面上交换速率的影响

在滴加HgCl2的状况下,应用实验室培养法研究了大亚湾大鹏澳网箱养殖海域各营养盐(NO2-N、NO3-N、NH4-N、PO4-P、SiO3-Si)在沉积物-海水界面上的交换通量;并根据改进的连续函数法计算了各营养盐在沉积物-海水界面上的交换速率.结果表明,在滴加HgCl2后,上述营养盐在沉积物-海水界面上的交换速率均明显下降,其减小幅度分别达到31.91%、52.27%、44.06%、48.05%和43.10%.加入HgCl2后,沉积物中微生物的分解作用和小型底栖生物的扰动作用受到抑制,有机物质向无机营养盐的转化能力和营养盐由沉积物向水体中的扩散能力减弱,各营养盐在沉积物-水界面上交换速率随之减小.

Influence of HgCl2 on nutrient exchange rates in sediment——water interface in fish cage area of Dapengao

The benthic fluxes of nutrients(NO2-N,NO3-N,NH4-N,PO4-P,SiO3-Si)in the sediment-water interface in fish cage area of Dapengao were measured by the laboratory incubation experiments with HgCl2,and a function method with dependence of the exchange rate was developed.In the function method,the average exchange rates of nutrients in the sediment-water interface were calculated.The results show that the exchange rates of NO2-N,NO3-N,NH4-N,PO4-P,SiO3-Si were decreased obviously with the influence of HgCl2,and the percent of decrease were 31.91,52.27,44.06,48.05 and 43.10 respectively.The catabolism of microorganism and the wriggle of benthos were restrained by HgCl2,so the decomposition of the organic matter and the diffusion of nutrients from sediment into water were weakened,and the nutrients exchange rates were decreased obviously.