EM菌对互花米草凋落物底泥中克氏原螯虾幼苗的影响

Effects of Effective Microorganisms on Red Swamp Crayfish Procambarusclarkii Juveniles in Spartina alterniflora Litter Bottom Matrix

为探究互花米草凋落物流入底泥后对滩涂底栖动物的影响及资源利用的适应性管理,以江苏盐城滩涂的淡水潮沟及两侧潮坪上的克氏原螯虾幼苗作为考察对象,设置添加功能菌群EM菌改良互花米草底质的EM组、互花米草底泥的草泥组及泥土组和清水组,对比克氏原螯虾幼苗4种微生境下30d的生存生长及底泥土壤性质。结果显示,EM组的存活率显著大于草泥组,与另外2组无显著差异;且体长平均增长量显著高于其他3组;平均体质量增加量显著高于底泥组和清水组,但与草泥组之间差异不显著。4组均为异速生长模式,且EM组克氏原螯虾幼苗肥满度最低。草泥组和EM组底泥中土壤微生物群落结构发生了改变,EM组底泥土壤有机碳和总氮含量均显著低于草泥组。试验结果表明,互花米草凋落物直接流入土壤底泥对克氏原螯虾的生存具有显著抑制效应,添加EM菌能改善底泥中互花米草腐解所造成的生境恶化现象,不但可以加快分解,抵消凋落物腐解的毒害,还能显著促进克氏原螯虾幼苗存活与生长。试验结果为克氏原螯虾在沿海滩涂养殖的推广提供技术支持,并为提高互花米草的生态利用价值和滩涂生态治理提供参考。

To evaluate the impact of Spartina alterniflora litter in bottom matrix on mudflat benthos and the adaptive management of resource utilization, the matrix properties and 30 days survival and growth were investigated in 4 microhabitats [S.alterniflora with effective microorganisms(EM) improving,thesingle Spartina alterniflora,themud,and thewater] of red swamp crayfish Procambarus clarkii juveniles. The results showed that the survival rate was significantly greater in the EM group than that in the S. alterniflora group, without significant difference from the other two groups. The red swamp crayfish in the EM group had the significantly higher average body length growth than the crayfish in the other three groups did, and the significantly higher average weight gain than those in the mud group and the water group, but close to the S. alterniflora group. All crayfish in four groups had allometric growth patterns, and the juveniles in the EM group had the minimal condition factor. The bottom matrix in the EM group and the S. alterniflora groups affected the soil microbial community structure. Compared with the single S. alterniflora group, there was lower total organic carbon (TOC) and total nitrogen (TN) contents at the bottom matrix of the EM group. It proved that the litter of S. alterniflora directly flowing into the mud matrix had a significant inhibitory effect on the survival of red swamp crayfish. Adding EM improved the deterioration of habitat caused by S. alterniflora decomposition in mud matrix,accelerating decomposition, reducing poison and promoting growth. These findings provide technical support for promotion of red swamp crayfish aquaculture in coastal mudflats and increase the ecological utilization value of S. alterniflora , which provides reference with ecological management of mudflats.