刺参不同养殖模式实验围隔内沉积物--水界面营养盐通量研究

Study on Nutrient Fluxes Across Sediment:Water Interface in Different Sea Cucumber Experimental Enclosures

研究刺参(Apostichopus japonicus)养殖模式对池塘底质的影响,于2007年5～11月间从不同养殖模式实验围隔内采得底泥样并通过实验室培养的方法测定了底泥耗氧率(SOD)及沉积物—水界面的N、P等。结果表明,投饵对SOD影响不显著(P>0.05),说明本实验条件下投饵没有造成实验围隔底泥中的有机物积累;7月份的SOD与其它月份间存在显著差异(P<0.05);大部分模式中沉积物释放溶解性无机磷酸盐(DIP)且不同月份之间的通量存在显著差异(P<0.05),不同模式之间的变化较复杂;在硝酸盐(NO3-+NO2-)通量结果中,投饵模式下的平均通量为非投饵模式下通量值的2～3倍,夏季的交换通量为冬季交换通量的2倍;当养殖密度较大时,非投饵模式中沉积物吸收氨氮的通量大于投饵模式中的通量,其它密度下投饵模式中沉积物释放氨氮的通量大于非投饵模式中的通量,并且随着养殖密度的增加通量值降低。

Sediment samples were collected from different sea cucumber （Apostichopus japonicus） experimental enclosures from May to November in 2007, and sediment-water fluxes of oxygen, nitrogen and phosphorus were investigated using laboratory chamber incubations. Sediment oxygen demand （SOD） in July was significantly different from those in the other months（P 〈 0.05）, and SOD values in enclosures were not significantly different between feed model and unfed model（P 〉 0.05）, indicating that feeding did not lead to enriched sediments. Dissolved inorganic phosphate （DIP） was released from the sediments in most enclosures. The fluxes of DIP of different months were significantly different（P 〈 0.05） and the variations of the fluxes in different feeding models were more complex. Fluxes of nitrate ＋ nitrite （NO3^- ＋ NO2^- ） in the enclosures with feeding models were two to three times higher than those with non-feed models, and in summer they were higher than in winter. Fluxes of ammonium uptaken by sediments in the enclosures with feeding models were greater than those with non-feed models when sea cucumber density was high. Fluxes of ammonium released from sediments were increased with increasing cultural density with enclosures of non-feed models greater than those of feeding models.