氮、磷、铁质量浓度对绿色颤藻生长的限制性条件

摘要

绿色颤藻（Oscillatoria chlorine）在虾池中大幅度增加时会释放微囊藻毒素，给对虾的健康养殖带来危害。文章分析不同质量浓度的氮（N）、磷（P）、铁（Fe3+）对绿色颤藻叶绿素 a 和藻体质量浓度的影响，探讨水中 N、P、Fe3+的质量浓度对绿色颤藻生长的限制性条件。结果显示，限制绿色颤藻叶绿素 a 质量浓度增加的条件是ρ（N）＜0.06 mg·L -1，ρ（P）＜9.93×10-2 mg·L -1和＞1.99 mg·L -1，ρ（Fe3+）＜2.58×10-2 mg·L -1和＞51.67 mg· L -1；限制藻体质量浓度增加的条件是ρ（N）＜12.36 mg·L -1，ρ（P）＜9.93×10-3 mg·L -1，ρ（Fe3+）＜5.16×10-3 mg·L -1和＞51.67 mg·L -1。绿色颤藻生长的阈值ρ（N）为0.06 mg·L -1、ρ（P）为9.93×10-3 mg·L -1、ρ（Fe3+）为5.16×10-3 mg·L -1。ρ（N）为7.42 mg·L -1、ρ（P）为4.96×10-2 mg·L -1和ρ（Fe3+）为5.16×10-3 mg·L -1是限制绿色颤藻叶绿素和藻体质量浓度增加的最低条件组合；N 是影响绿色颤藻叶绿素 a 和藻体质量浓度的主要因子，其次是 Fe3+和 P。在对虾养殖过程中可以通过换水或循环水系统除去水体中的含 N 污染物，降低养殖水体中溶解态 N 含量，从而控制绿色颤藻的快速增长。%The proliferation of Oscillatoria chlorine will release toxins which are harmful to prawn growth in the aquaculture ponds. We investigated the limiting concentrations of nitrogen(N),phosphorus(P)and iron(Fe3 + )to the growth of O. chlorine as well as the effects of different N,P and Fe3 + concentrations on chlorophyll a content and dry weight of O. chlorine. The results show that N con-centration < 0. 06 mg·L - 1 ,P concentration < 9. 93 × 10 - 2 mg·L - 1 and > 1. 99 mg·L - 1 ,and Fe3 + concentration < 2. 58 × 10 - 2 mg·L - 1 and > 51. 67 mg·L - 1 ,limited the increase of chlorophyll a content;N concentration < 12. 36 mg·L - 1 ,P concentration <9. 93 × 10 - 3 mg·L - 1 and the Fe3 + concentration < 5. 16 × 10 - 3 mg·L - 1 and > 51. 67mg·L - 1 ,limited the increase of dry weight. The threshold concentrations of N,P and Fe3 + for the growth of O. chlorine were 0. 06 mg·L - 1 ,9. 93 × 10 - 3 mg·L - 1 and 5. 16 × 10 - 3 mg·L - 1 ,respectively. The combined concentrations which limited the increase of chlorophyll a contents and dry weight of O. chlorine were 7. 42 mg·L - 1 of N,4. 96 × 10 - 2 mg·L - 1 of P and 5. 16 × 10 - 3 mg·L - 1 of Fe3 + ,respectively. Nitrogen had the strongest effect on chlorophyll a content and dry weight,followed by Fe3 + and P. It is suggested that the rapid proliferation of the O. chlorine might be controlled through water exchange or circulation to reduce the dissolved nitrogen content in the aquaculture ponds.