摘要
污损生物是影响贝类养殖业生产效率的重要因素。附着在养殖生物贝壳上的污损生物影响养殖生物的生长和存活。大部分污损生物是滤食性捕食者,这些污损生物附着在养殖生物贝壳上竞争食物与空间导致贝类生长速度减慢。本实验主要研究有污损生物附着的扇贝及没有污损附着的扇贝在摄食及排泄上的差异,用以说明污损生物对养殖生物摄食及排泄的影响。本研究对chlorophyll a和TPM的吸收速率进行了测定,对NH4-N,NO2-N,NO3-N,PO4-P的排泄速率进行了测定,对摄食的浮游植物进行了种类鉴定。研究结果表明,有污损生物附着的扇贝及没有污损附着的扇贝在对浮游植物及颗粒物的吸收速率上存在明显差异(P<0.001)。在氨及亚硝态氮排泄速率上也存在明显差异(P<0.001)。两者吸收NO3-N,且吸收速率无差异。通过对摄食的浮游植物种类的鉴定表明,有污损生物附着的扇贝摄食的浮游植物种类要高于没有污损附着的扇贝,且摄食种类有重叠。对同一类的某些浮游植物,有污损生物附着的扇贝的摄食要高于干净扇贝。本研究结果表明,污损生物对浮游植物的摄食及水中氨氮浓度的提高贡献很大,与养殖生物之间存在食物竞争。
Biofouling is an important factor that affects bivalve farming industry. Fouling organisms may reduce growth and survival rate of the cultured species. Fouler are often filter feeders, so they are potential competitors for food resource with the cultured species. The present study was conducted to measure the impact of fouling on food uptake and nutrient release in April, 2006 in Daya Bay near Guangzhou, China. Results showed that fouling organisms had significant effect on food uptake and nutrient release. The chlorophyll a uptake rate of fouled scallops was 7.53 / Lh ±1.416 / Lh in April, significantly higher than those of cleaned scallops, Le., 4.23 / Lh±2.744 / Lh. The consumption of total particulate matter by fouled scallops in April was 5.52 / Lh± 0.818 / Lh; the corresponding results for cleaned scallops are 2.49 / Lh ±0.614 / Lh Fouling increased ammonia release significantly. The ammonia release rate of fouled scallops was 33.81/Lh ±7.699 / Lh in April, while cleaned scallops released 2.46 / Lh ±0.511 / Lh ammonia. Phosphate uptake of fouled scallops was 2.01± 0.699 / Lh and cleaned scallops released phosphate 6.01 / Lh ＋ 0.876 / Lh in April. There was not significant difference in nitrate consumption between fouled and cleaned scallops. According to the phytoplankton classification of input and output water samples, fouled scallops filtered more phytoplankton species than cleaned scallops. Therefore, this study showed that fouling contributed much to phytoplankton depletion and concentration increase of ammonia in water.
基金
supported by National Science Foundation of Huaihai Institute of Technology (No. KQ07102)
Open Project Program of the Key Laboratory of Marine Bio-resources Sustainable Utilization, SCSIO, CAS (No. KK09001)
