鳝池的建造与处理技术

根据多年的研究和生产实践,本文提出鳝池建造的五个原则,从面积、形状、水口、鱼巢、食台和泥层等方面总结了黄鳝有土养殖池、无土养殖池和混合型养殖池的建造技术,还从脱碱、清池和水草投放等三方面概括了鳝池的处理技术。

Layered farming for Marsupenaeus japonicus Bate

Marsupenaeusjaponicus Bate is one of the most valuable cultured shrimp species in China and outdoor earthen pond farming is the most common method of culturing this organism. The need to increase soil usage efficiency in aquaculture has been recognized and a great deal of research effort has been directed toward development of super-intensive farming systems. However, current research and development in this field is largely devoted to Litopenaeus vannamei Boone, while to M.japonicus Bate it has been neglected. In this study, a layered fanning system was designed and a 66-day study was conducted in M.japonicus Bate culture. The system comprised bracket and sand layers that divided a shrimp tank filled to a depth of 1.2 m into four water layers. Conventional tank culture （unlayered） was used as a control. The results show that survival rate, feed conversion efficiency and production of M.japonicus Bate in the layered farming system were 68%, 18%, and 0.59 kg/m^2, respectively, all of which are significantly higher than in the unlayered fanning system （P〈0.01）. These findings confirmed the possibility of using a layered system to culture M. japonicus Bate.

Ecological effects of co-culturing sea cucumber Apostichopus japonicus (Selenka) with scallop Chlamys farreri in earthen ponds

Monthly changes in sedimentation and sediment properties were studied for three different culture treatments： sea cucumber monoculture （Mc）, sea cucumber and scallop polyculture （Ps-c） and scallop monoculture （Ms）. Results indicated that the survival rate of sea cucumber was significantly higher in Ps-c cultures than in Mc cultures. Sea cucumber yield was 69.6% higher in Ps-c culture than in Mc culture. No significant differences in body weight and scallop shell length were found between Ps-c and Ms cultures. The mean sedimentation rate of total particulate matter （TPM） was 72.2 g/（m^2.d） in Ps-c cultures, with a maximum of 119.7 g/（mE.d）, which was markedly higher than that of Mc （mean value）. Sedimentation rates of organic matter （OM）, total organic carbon （TOC）, total nitrogen （TN） and total phosphorus （TP） in Ps-c cultures were also significantly higher than those in Mc cultures. TOC and TN contents of sediment increased rapidly in the first 5 months in Ms cultures and remained at a high level. TOC and TN contents in Mc and Ps-c cultures decreased during sea cucumber feeding seasons and increased during sea cucumber dormancy periods （summer and winter）. The study demonstrates that co-culture of sea cucumber and scallop in earthen ponds is an alternative way to alleviate nutrient loads and improve water quality in coastal aquaculture systems. Moreover, it provides the additional benefit of an increased sea cucumber yield.

Spatial Variation of Soil Inorganic Carbon Reserves of Typical Estuarine Wetlands in Jiaozhou Bay, China

The storage of inorganic carbon in estuarine wetlands is of great significance for mitigating global warming. The Dagu River estuary and Yanghe River estuary of Jiaozhou Bay were selected as sampling areas, and data analysis was carried out by Duncan method to explore the distribution characteristics and influencing factors of soil inorganic carbon(SIC) reserves. The results showed that increasing distance from the estuary led to higher reserves in the mudflat along the coastal zone. The scouring action of seawater bodies was the main factor driving this distribution. In the vertical section, the SIC reserves in 40–60 cm depth were relatively high, accounting for 34.11% of the 0–60 cm soil depth, and resulting from the transport of water and salt in seawater. In the river flat along the vertical coastal zone, the SIC reserves first decreased and then increased with increasing distance from the sea, and the SIC reserves in 0–20 cm depth were relatively high in the vertical section, accounting for 38.18% of the 0–60 cm soil depth. These reserves were affected by synergetic factors such as oceanic factors and anthropogenic activities. The invasion of Spartina alterniflora decreased the SIC reserves of wetlands, mainly due to its root transformation and the differences of growth characteristics and years being the main reasons for the observed decreases. Aquaculture activities changed the physical and chemical properties of the soil in aquaculture ponds, and consequently changed the distribution of SIC reserves.