海蜇降解对生源要素的释放研究

Release of nutrient element in the test of Rhopilema esculentum Kishinouye decomposition

以海蜇为研究对象,通过模拟实验研究了海蜇降解过程对水体溶解氧和营养盐的影响。研究结果表明:海蜇降解显著消耗水体溶解氧,在降解的前3 d溶解氧消耗速率最快,实验水体海蜇量越多其溶解氧消耗就越大。海蜇降解向水体释放大量的DOC、NH4-N,且随实验海蜇量的增多其NH4-N释放量逐渐增加;5 kg组NH4-N最高浓度可达2 150μmol/L,为对照组的100倍;由于反硝化作用NO3-N、NO2-N的浓度随实验时间的增加浓度逐渐降低,至第3 d其浓度降低至未检出。海蜇降解也向水体释放PO4-P和SiO3-Si,且随实验水体海蜇量的增多其PO4-P和SiO3-Si释放量逐渐增加,但SiO3-Si增加幅度较小。降解产物中N/P值较高,最高值高达1 707,平均值为195。水母大量暴发会对海洋生态系统产生重大影响。

To understand the influence of the decaying process after a large jellyfish bloom on marine environment,laboratory simulation experiments were performed to study the variations of DO and nutrients during the decomposition process of Rhopilema esculentum. The results suggested that the decomposition of R. esculentum needed a great deal of oxygen,and the fastest oxygen compostion rate was found during the first three days. Different amount of R. esculentum in the seawaters caused variations in the extents of DO consumption during the decomposition process. A great amount of DOC and NH 4-N were released during the decomposition process. The concentration of NH 4-N was highest in the whole degradation process,which reached 2 150 μmol / L. Concentrations of NO 3-N and NO 2-N continued decline because of de-nitrification,and concentrations reached undetected level in the third day. The release of PO 4-P and SiO 3-Si increased with the amount of R. esculentum in the seawater. The N / P ratio can reach 1 707,with an average of 195. The explosion of jellyfish will have a great influence on the marine ecosystem.