To understand the factors causing frequent outbreaks of harmful algae blooms in the Taihu Lake, China, we studied water quality and nutrient budget in Chinese mitten crab (Eriocheir sinensis) farm ponds in the eastern...To understand the factors causing frequent outbreaks of harmful algae blooms in the Taihu Lake, China, we studied water quality and nutrient budget in Chinese mitten crab (Eriocheir sinensis) farm ponds in the eastern part of the lake from November 2007 to December 2009. We estimated the nitrogen (N), phosphorus (P), and chemical oxygen demand (COD) loads. Materials input and output ponds, water exchange, and applied management practices of 838.5-hm2 crab ponds were surveyed using questionnaires. Water quality of 12 ponds, which were located no more than 2 km from East Taihu Lake, were monitored. The results show that water quality in the crab ponds was better than reference data. Feeds, including corn seed, commercial feed, trash fish, and gastropod, were the major sources of N and P input in the crab ponds, contributing 88.7% and 94.9%, respectively. In total, 60.5% of N and 37.3% of P were sequestered by macrophytes, and only 15.7% and 8.5% of them were discharged as effluent. The net loads of N and P in effluent were 16.43 kg/hm2/cycle and 2.16 kg/hm2/cycle, respectively, while the COD load was -17.88 kg/hm2/cycle. This indicated that crab farming caused minor negative impact on the trophic status of the lake area, which was attenuated by macrophytes. However, wastewater purification is still necessary in crab faming.展开更多
本试验旨在研究普通棉籽粕(CSM)和发酵棉籽粕(FCSM)替代鱼粉对中华绒螯蟹(Eriocheir sinensis)幼蟹生长性能、体成分和肝胰腺消化酶活性的影响。选用初始均重为(0.56±0.04)g的中华绒螯蟹幼蟹660只,随机分成11组,每组3个重复,每个重...本试验旨在研究普通棉籽粕(CSM)和发酵棉籽粕(FCSM)替代鱼粉对中华绒螯蟹(Eriocheir sinensis)幼蟹生长性能、体成分和肝胰腺消化酶活性的影响。选用初始均重为(0.56±0.04)g的中华绒螯蟹幼蟹660只,随机分成11组,每组3个重复,每个重复20只。配制CSM添加量分别为0、8.0%、16.0%、24.0%、32.0%、40.0%(分别记为CSM0、CSM8、CSM16、CSM24、CSM32、CSM40组)和FCSM添加量分别为8.0%、16.0%、24.0%、32.0%、47.5%(分别记为FCSM8、FCSM16、FCSM24、FCSM32、FCSM47.5组)的11种等氮(粗蛋白质,38.39%)等能(总能,19.18 M J/kg)试验饲料。试验期为6周。结果表明:CSM8、CSM16、FCSM8、FCSM16、FCSM24组的增重率、特定生长率、成活率与对照组(CSM0组)差异不显著(P>0.05)。CSM8、FCSM8、FCSM16、FCSM24组的全蟹粗蛋白质含量与对照组亦无显著差异(P>0.05)。饲料中CSM添加量超过16%或FCSM添加量超过24%时,增重率、特定生长率、成活率和全蟹粗蛋白质含量显著低于对照组(P<0.05)。不同水平的CSM和FCSM替代鱼粉对全蟹水分、粗脂肪、粗灰分含量以及肝胰腺脂肪酶活性的影响均不显著(P>0.05)。随着CSM或FCSM替代水平的升高,肝胰腺胃蛋白酶和胰蛋白酶活性逐渐下降,而淀粉酶和纤维素酶活性则逐渐升高。在相同替代水平下,FCSM组的胃蛋白酶和胰蛋白酶活性均不同程度地高于CSM组,而FCSM组的纤维素酶活性则显著低于CSM组(P<0.05)。由此得出,作为中华绒螯蟹幼蟹饲料中鱼粉的替代蛋白质源时,CSM的适宜添加量为16%,FCSM的适宜添加量为24%。此外,相同替代水平下FCSM的替代效果好于CSM。展开更多
基金Supported by the Major Projects on Control and Rectification of Water Body Pollution (No. 2008ZX07101-012)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KZCX1-YW14)+1 种基金the Aquaculture "three projects" of Jiangsu (No. J2009-12)the Agricultural Basic Research Fund of Suzhou (No. YJG0912)
文摘To understand the factors causing frequent outbreaks of harmful algae blooms in the Taihu Lake, China, we studied water quality and nutrient budget in Chinese mitten crab (Eriocheir sinensis) farm ponds in the eastern part of the lake from November 2007 to December 2009. We estimated the nitrogen (N), phosphorus (P), and chemical oxygen demand (COD) loads. Materials input and output ponds, water exchange, and applied management practices of 838.5-hm2 crab ponds were surveyed using questionnaires. Water quality of 12 ponds, which were located no more than 2 km from East Taihu Lake, were monitored. The results show that water quality in the crab ponds was better than reference data. Feeds, including corn seed, commercial feed, trash fish, and gastropod, were the major sources of N and P input in the crab ponds, contributing 88.7% and 94.9%, respectively. In total, 60.5% of N and 37.3% of P were sequestered by macrophytes, and only 15.7% and 8.5% of them were discharged as effluent. The net loads of N and P in effluent were 16.43 kg/hm2/cycle and 2.16 kg/hm2/cycle, respectively, while the COD load was -17.88 kg/hm2/cycle. This indicated that crab farming caused minor negative impact on the trophic status of the lake area, which was attenuated by macrophytes. However, wastewater purification is still necessary in crab faming.
文摘本试验旨在研究普通棉籽粕(CSM)和发酵棉籽粕(FCSM)替代鱼粉对中华绒螯蟹(Eriocheir sinensis)幼蟹生长性能、体成分和肝胰腺消化酶活性的影响。选用初始均重为(0.56±0.04)g的中华绒螯蟹幼蟹660只,随机分成11组,每组3个重复,每个重复20只。配制CSM添加量分别为0、8.0%、16.0%、24.0%、32.0%、40.0%(分别记为CSM0、CSM8、CSM16、CSM24、CSM32、CSM40组)和FCSM添加量分别为8.0%、16.0%、24.0%、32.0%、47.5%(分别记为FCSM8、FCSM16、FCSM24、FCSM32、FCSM47.5组)的11种等氮(粗蛋白质,38.39%)等能(总能,19.18 M J/kg)试验饲料。试验期为6周。结果表明:CSM8、CSM16、FCSM8、FCSM16、FCSM24组的增重率、特定生长率、成活率与对照组(CSM0组)差异不显著(P>0.05)。CSM8、FCSM8、FCSM16、FCSM24组的全蟹粗蛋白质含量与对照组亦无显著差异(P>0.05)。饲料中CSM添加量超过16%或FCSM添加量超过24%时,增重率、特定生长率、成活率和全蟹粗蛋白质含量显著低于对照组(P<0.05)。不同水平的CSM和FCSM替代鱼粉对全蟹水分、粗脂肪、粗灰分含量以及肝胰腺脂肪酶活性的影响均不显著(P>0.05)。随着CSM或FCSM替代水平的升高,肝胰腺胃蛋白酶和胰蛋白酶活性逐渐下降,而淀粉酶和纤维素酶活性则逐渐升高。在相同替代水平下,FCSM组的胃蛋白酶和胰蛋白酶活性均不同程度地高于CSM组,而FCSM组的纤维素酶活性则显著低于CSM组(P<0.05)。由此得出,作为中华绒螯蟹幼蟹饲料中鱼粉的替代蛋白质源时,CSM的适宜添加量为16%,FCSM的适宜添加量为24%。此外,相同替代水平下FCSM的替代效果好于CSM。
