绍兴市凡纳滨对虾围垦滩涂养殖池塘的理化环境和浮游植物

2016年和2017年分别调查了位于浙江省绍兴市滨海新区的12口凡纳滨对虾围垦滩涂养殖池塘内的理化环境和浮游植物。结果显示:池塘内盐度变化范围为0~2,溶氧为6.2~13.9 mg/L,pH为7.5~9.8,总氨氮(TAN)为0.00~0.72 mg/L,亚硝酸盐氮(NO_2~--N)为0.00~1.70 mg/L,硝酸盐氮(NO_3~--N)为0.18~4.77 mg/L,总氮为1.74~6.08 mg/L,总磷为0.20~2.72 mg/L,总有机碳为1.88~42.57 mg/L,C/N为10~39。池塘内浮游植物种类隶属6门、24科、42属,其中蓝藻和绿藻为优势种。浮游植物生物量为(0.15~2.30)×107cell/L,叶绿素a(Chl.a)为2.62~37.24μg/L。Chl.a与蓝藻生物量显著正相关。NO_2~--N和NO3--N均与pH显著负相关。初步分析认为高pH可能是导致2016年池塘养殖凡纳滨对虾死亡率较高的重要原因,因此采取措施控制蓝藻生物量和水体的p H应有助于提高对虾养殖的存活率。

Physicochemical environment and phytoplankton in Litopenarus vannamei ponds located in the diked tidal flat in Shaoxing city

The physicochemical environment and phytoplankton in Litopenarus vannamei ponds located in the diked tidal flat in Binhai New District,Shaoxing City,Zhejiang Province were surveyed respectively in 2016 and 2017. In these ponds,the salinity,dissolved oxygen,pH,total ammonia nitrogen(TAN),nitrite-nitrogen ( NO-2-N) ,nitrate-nitrogen( NO-3-N) ,total nitrogen,total phosphorus,total organic carbon and C/N ratio were 0~2,6. 2~13. 9 mg/L,7. 5~9. 8,0. 00~0. 72 mg/L,0. 00~1. 70 mg/L,0. 18~4. 77 mg/L,1. 74~6. 08 mg/L,0. 20~2. 72 mg/L,1. 88~42. 57 mg/L and 10~39,respectively. A total of 42 genus of phytoplankton,which belonged to 24 families and 6 phylums,were observed from the ponds,where blue algae and green algae are dominant. The phytoplankton biomass was (0. 15~2. 30) × 107 cell/L,and Chl. a concentration was 2. 62~37. 24 μg/L. The Chl. a concentration was positively correlated to the biomass of blue algae. The NO-2-N and NO-3-N were negatively correlated to pH. Preliminary analysis suggested that the high mortality of Litopenarus vannamei occurred in the ponds in 2016 might be attributed to high pH. Therefore, proper control of the biomass of blue algae and pH should be a way to improve the survival rate of Litopenarus vannamei in these ponds.