室内观赏鱼池自净化生态系统的构建

[目的]构建室内观赏鱼池生态自净化系统.[方法]设计了水泵过滤池、入水池、生态净化池和观赏鱼池.结合使用常规水族生物材料,首次在生态净化池投放了单肠目、大口虫目、三肠目涡虫、水螅和浮游动物等.对常见5种水生观赏植物以及硝化细菌的水净化功能进行检测.[结果]实现了鱼池环境物种的多样性,形成了完整的食物链体系,使观赏鱼池获得稳定的水生态平衡环境,构建了具有自净化功能的水生态调控系统.不同的水生观赏植物对水体的净化功能有显著差异.[结论]构建的室内观赏鱼池自净化生态系统方法简便、效果极为显著,可节约人工及水资源均达90％以上,具有应用与推广价值.     

模糊控制在水产养殖监控系统中的应用

采用一种模仿人的控制策略的模糊控制方法,建立了模糊数学模型,设计了模糊控制器对水产养殖中养鱼池环境进行控制。结果表明:其在水质监控系统中具有较好的控制效果。     

鱼塘栽培对南湖菱生长发育、营养品质及安全性的影响

对鱼塘栽培和外河栽培两种模式下南湖菱的生育期、商品性、营养品质及产品安全性等方面进行系统比较。结果表明,鱼塘栽培南湖菱虽然在单果质量、出果率等商品性状及生长发育指标较外河栽培的有一定程度降低,但果实的营养成分包括粗蛋白和氨基酸总量较外河栽培显著提高,安全性指标与外河无明显差异,均符合无公害农产品的各项指标,同时鱼塘栽培有利于南湖菱生育期提前,促进南湖菱提早上市。     

The diet and growth of larval and juvenile pikeperch (Stizostedion lucioperca (L.)): A comparative study of fishponds and a reservoir

Diet of larval and juvenile pikeperch (Stizostedion lucioperca) reared in ponds wasinvestigated and compared with the diet ofpikeperch from a reservoir. The standard lengthof first feeding pikeperch larvae in ponds was6.1 mm, on average, and although rotifers werepresent in the diet, their numericalcontribution can be considered asinsubstantial. Rotifers were soon replaced bynauplii of cyclopoid copepods, which werehighly positively selected and contributedlargely to the diet up to a larval length of 10 mm.Daphnia spp. were consumed from the onsetof exogenous feeding, but were not positivelyselected until 15 mm. Anothersmaller cladoceran Bosmina longirostriswas highly negatively selected and did notcontribute significantly to the diet. A clearpositive selection for larger relatively tosmaller prey and a preference for Daphniafrom a body length of 15 mm onwards could beobserved. In the reservoir, rotifers were notfound in the diet of pikeperch larvae even inthe smallest individuals. Dominant food itemswere nauplii and 1st copepodite instar ofEudiaptomus gracilis and Cyclopsspp. Cladocerans – Daphnia galeata andto a lesser extent Diaphanosomabrachyurum appeared in the pikeperch diet at alength of about 10 mm. A shift from copepods toDaphnia spp. and especiallyLeptodora kindtii could be recognised inpikeperch at a length of 20 mm. When comparing ourdata from nursing ponds with the data fromímov reservoir, similar trends in dietcomposition were observed.Growth of pikeperch was found significantlyfaster in nursing ponds than in the reservoir.Slow growth of reservoir pikeperch was probablyan artefact due to the prolonged spawningperiod in the reservoir. Larvae and juvenilesfrom later spawnings decreased the average sizeof the population over the studied period. Innursing ponds lowest average standard length atharvest was found in the pond with the highestnumbers of fish, and vice versa in the pondwith the lowest numbers the largest standardlength was recorded. This result corresponds tothe increased intracohort food competitionamong juvenile pikeperch with increasingstocking density.     

Experiments on the operation of a combined aquaculture-algae system

A combined aquaculture-algae system was developed for the purification and reuse of effluent water from intensive fish production in a combination of a high-rate algal pond and extensive fishpond. The integrated system was operated as a closed system, thus the water demand was reduced through the recirculation of the treated water. The pilot-scale experimental system consisted of three different compartments: tanks for intensive fish production, an algal pond where the excess nutrients are removed by algae uptake and a fishpond where the produced algae biomass was consumed by fish. The objective of this study was to describe and evaluate the nutrient transformation efficiency of the combined system through the analysis of the organic carbon, nitrogen and phosphorus budgets.     

Changes in fish production effectivity in eutrophic fishponds—impact of zooplankton structure

Fishponds were and are purposeful water structures. Fish production is their main function and rational management is an inevitable condition for their existence. The present high level of fishpond eutrophication results in nutrients overloading. The effect of the high level of nutrients is emphasized by top-down control of zooplankton by high fish stock densities. Currently the zooplankton is represented by small species such as nauplii, small cyclopoid copepods, small species of Cladocera and rotifers that are not so effective filtrators. The high eutrophic level brings about high primary production (mostly with predominance of inedible Cyanophytes) which cannot be used by this type of zooplankton. The main consequences of high eutrophication are large fluctuations in basic environmental parameters and a decrease in production effectivity. It is expected that the utilization efficiency of the enormous primary production through zooplankton into fish production is low. Therefore, maintaining ecological stability and healthy, sound functioning of the ecosystem, meaning without considerable fluctuations, represents an important task in sustainable fishpond management.     

预测鱼塘拂晓溶氧浓度的新模式

根据对鱼塘养鱼水体生态环境因子的现场实验,分析了鱼塘溶氧浓度的变化规律。提出了预测鱼塘拂晓溶氧浓度的新模式,并通过实例分析,证明了新模式的准确性。