哑铃湾网箱养殖海域沉积物中氮的地球化学形态分配特征

Distribution Characteristics of the Environmental Geochemical Forms for Nitrogen in the Sediment in Cage Farming Sea Area at Yaling Bay

对哑铃湾养殖网箱下沉积物、养殖区和非养殖区沉积物中氮的地球化学形态分配特征做了4个季度的比较研究。结果表明:除NNEX以外,其他形态氮的含量都是养殖网箱下沉积物>养殖区沉积物>非养殖区沉积物,并且随着养殖年限的增加,这一规律越明显;但各形态氮之间的比例在三类海域沉积物中有所不同,w(NO) w(NT),w(NEX) w(NI),w(NH+4-N) w(NEX)都是养殖网箱下沉积物>养殖区沉积物>非养殖区沉积物,养殖历史最长的S6站点养殖网箱下沉积物比例最高,网箱养殖明显增大了NO,NEX和NH+3-N) 4-N的含量,而w(NI) w(NT),w(NNEX) w(NI),w(NO-w(NEX),w(NO-2-N) w(NEX)则呈相反的规律;各形态氮之间及其与有机质之间的相关性在三类海域沉积物中也不尽相同,养殖网箱下沉积物中,w(NH+4-N)与w(NT),w(NO),w(NI)及有机质与w(NT),w(NO)都存在显著的正相关关系。

Distribution characteristics of the environmental geochemical forms for nitrogen in the sediments taken from natural region, cultural region and under the cages of Yaling Bay in four seasons are studied. The results show that the contents of all forms for nitrogen, except for N_(NEX), in the sediments are higher under the cages than in cultural region and higher in cultural region than in natural region. This rule increases obviously with time of cage forming. The ratios of various forms of nitrogen differ among the three marine regions. The average contents ratios of N_O/N_T, N_(EX)/N_I, NH^+_4-N/N_(EX) are in the order of under the cages > cultural region > natural region, but the average contents ratios of N_I/N_T, N_(NEX)/N_I, NO^-_3-N/N_(EX), NO^-_2-N/N_(EX) have the order in reverse. The correlations of all forms for nitrogen and between them and organic matter are different in the three kinds of sediments, and the positive correlations between contents of NH^+_4-N and N_T, N_O, N_I are found, as well as between organic matter (and N_T, N_O.)