【作者】 许忠能；

【导师】 林小涛；

【作者基本信息】 暨南大学 ， 水生生物学， 2007， 博士

【摘要】 本文采用野外调查及室内实验生态的方法研究了惠阳大亚湾海水网箱养殖区生态系统中碳、氮、硫、磷、钙、镁、铁、锌、铜、钼、硒、锶的分配与流动特征。分别测定饵料、养殖鱼类、网箱附着生物群落、海水、微生物、底栖生物、底泥中的元素分配及估算了流动速率，同时，在实验室测定了海水网箱养殖过程中自身污染物的形式与数量。不同种类的饵料、不同体重的饵料鱼中各组织的元素含量都会有差异。其中，各种饵料以及饵料鱼各组织的碳含量为215-483 mg／g，氮含量为52-133 mg／g，磷含量为8-80 mg／g，钙含量为2-154 mg／g。测定了卵形鲳鲹、不同性别的花尾胡椒鲷、不同体重的斜带石斑鱼以及这些鱼不同器官组织的碳、氮、硫、磷、钙、镁、铁、锌、铜、钼、硒、锶元素含量。这三种鱼所含的碳、氮、磷、钙平均为447.5mg／g、110.8mg／g、24.3 mg／g、38.7mg／g。种类、性别、体重影响了网箱养殖鱼类各器官组织的元素含量。在附着生物中，贻贝与牡蛎所占的生物量最大。经估算，养殖区附着生物群落所含的碳、氮、磷、钙分别为7.8×10⁶g、9.0×10⁵ g、6.8×10⁴ g、1.3×10⁷ g。测定了惠阳海水网箱养殖区及附近海域海水中氮、磷、钙、镁、铁、锌、锶等元素的时空变化。海水网箱养殖区海水中的氮、磷、钙含量分别为0.013-0.032mg／L、0.0048-0.0220 mg／L、64-180 mg／l。网箱养殖过程对养殖区海水元素含量产生显著影响，养殖区的氮、磷含量比非养殖区高（P＜0.05），而钙、锶含量比非养殖区低（P＜0.05）。设计了平板计数法与生物量一菌落标准曲线结合的实验方案，测定海水中细菌与真菌的生物量，分析菌体中碳、氮、硫、磷、钙、镁、铁、锌、铜、钼、硒、锶元素的含量。养殖区中细菌与真菌的生物量分别为5.4×10^-4 mg／L、6.3×10^-5mg／L，细菌中所氮、磷、钙含量分别为78 mg／g、7.2 mg／g、41 mg／g。测定了惠阳海水网箱养殖区及附近海域底泥中碳、氮、硫、磷、钙、镁、铁、锌、铜、钼、硒、锶元素含量的时空变化，并分析了大型底栖生物的现存量与元素含量。养殖区底泥的碳、磷、钙、铜、锶含量高于非养殖区。养殖区底泥中的碳、钙含量分别14.8g／（L底泥）、30.6 g／（L底泥）。大型底栖生物中，贝类的生物量最高。养殖区大型底栖生物中的碳、钙分别为25.2 g／（L底泥）、43.7g／L底泥)。养殖过程中以饵料鱼投喂养殖动物产生的氮、磷、能量负荷以残饵、粪便、排尿、脱落物等形式存在，其中残饵分为骨、软组织、鳞，它们的元素含量有较大的差别。在不断接受投饵的海水网箱养殖生态系统中，各种元素在网箱、海水、底泥之间及养殖生态系统内外之间流动。惠阳大亚湾海水网箱养殖生态系统中的氮与磷不断向系统外输出。养殖区中存在象泵一样的机制，把钙从附近海区的海水中“泵”入养殖区，再“泵”入养殖区海底。更多还原

【Abstract】 Distribution of carbon（C）, nitrogen（N）, sulfur（S）, phosphorus（P）, calcium（Ca）, magnesium（Mg）, iron（Fe）, zinc（Zn）, copper（Cu）, molybdenum（Mo）, selenium（Se）, and strontium（Sr） in marine cage-culture ecosystem in Daya Bay was studied based on investigation in field and experiments in laboratory. Forage fish, cultural fish, epiorganisms on cages, seawater, microorganisms, benthos, and sediments in marine cage-culture areas were sampled in the field to measured element contents. Nitrogen and phosphorus waste outputs of four marine cage-cultured fish fed with trash fish were investigated under laboratory conditions.The elements were analyzed in forage fish, compound feed, some tissues of forage fish. The results showed that the concentrations of C, N, S, and Ca in feed were 215-483 mg/g, 52-133 mg/g, 8-80 mg/g, and 2-154 mg/go respectively. Concentration of elements in different species of forage fish and tissues in trash fish with different body weights varied. On average the levels of C, N, S, and Ca in cultural fish were 447.5mg/g, 10.8mg/g, 24.3 mg/g, and 38 .7mg/go respectively. There were sex, species, and body weight differences in element contents in tissues of cultural fish. Mussels and oysters predominated the periphyton communities on cages, and the epiorganisms in the cultural areas contained 7.8×10⁶ g, 9.0×10⁵ go 6.8×10⁴ g, and 1.3×10⁷ g of C, N, P, and Ca, respectively. Concentrations of N, P, and Ca of Seawater in cultural areas were 0.013-0.032 mg/L, 0.0048-0.0220 mg/L, and 64-180 mg/L, respectively. Induced by marine cage-culture, the N and P levels in cultural seawater were higher than those of seawater in control plots, but contents of Ca and Sr in seawater in cultural areas were higher than those of control plots. In the present study, a new method based on biomass-colony standard curve was established to measure biomass of bacteria and fungi. The biomasses of bacteria and fungi in cage-cultural seawater were 5.4×10^-4 mg/L and 6.3×10^-5 mg/L, respectively, and contents of N, P, and Ca in bacteria were 78 mg/g, 7.2 mg/g, and 41 mg/g, respectively. Contents of C, P, Ca, Cu, and Sr in sediments of cage-cultural areas were significantly higher than those of control plots. C and Ca levels in sediments in cage-cultural areas were 14.8 g·L fresh sediment^-1 and 30.6 g·L fresh sediment^-1, respectively. Mussels and oysters dominated the benthic communities in cage-cultural areas. C and Ca stored in bottom fauna of cage-cultural areas were 25.2 g·L fresh sediment^-1 and 43.7 g·L fresh sediment^-1, respectively.The results of laboratory experiments showed that waste outputs of cultured fish fed with trash fish were divided into soft tissues in uneaten feed, bones in uneaten feed, scales in uneaten feed, faeces, urine, caducous scales, and other parts. Element differences of these wastes were examined.In marine cage-culture ecosystem which always received feeds, elements were distributed in cages, seawater, and sediment, and some of elements were transported in or out the ecosystem. Some N and P transported by seawater moved out the ecosystem. There was a pump-like mechanism that Ca was pumped from seawater nearby to the cage-culture ecosystem, and then been sunk to the sediment.更多还原