Effects of different types of nutrient effluent from shrimp ponds on the seedling growth of Kandelia obovata

Extensive shrimp ponds are located next to the landward edges of most of mangrove forests in China. A shrimp pond may influence mangroves by（1） routine effluent between pond and tide, and（2） dredging effluent from pond-dredging at least once a year. Our study consisted of two experiments to study the effects of these two effluents on the seedling growth of Kandelia obovata. One experiment simulated the effects of routine effluents.The other simulated four sedimentation thicknesses（0 cm, 2 cm, 4 cm, 8 cm） over mangrove soils by dredging effluent from pond-dredging, and revealed the cumulative effects of dredging effluents on K. obovata. At each of the three fixed salinities, i.e., 5, 15 and 25, routine effluent did not result in significant differences in each of the measured growth parameters of K. obovata seedlings. However, effects of dredging effluent on seedling growth of K. obovata were related with sedimentation thickness. Most growth parameters showed maximum values at sedimentation thickness 4 cm. The data indicated that K. obovata accelerated its growth under moderate sedimentation thicknesses and it was tolerant and adaptable to shrimp pond-cleaning effluent sediments up to about 8 cm in our experiment.

GROWING NIPA PALM FOR RESTORATION OF ABANDONED SHRIMP PONDS

Rapid increase in the production of marine shrimps in the coastal zone has resulted in large-scale con-version of mangrove forests to shrimp ponds.Productions of the shrimps in some regions have been unstable.Conse-quently,a number of ponds are left idle.Restoring environmental conditions within the pond site by planting a suitablemangrove species considered an option.The experiment herein was carried out to explore the effect of planting methodson growth of Nipa palm in abandoned shrimp ponds in the Southern Thailand.Economically,coastal villagers in this areaearn their income from the palm in several ways,the most importantly in Nipa sugar production.Most seedlings wereplanted on top of furrows were constructed in the pond to avoid flooding,except for some seedlings which were planted inthe pond base where additional pond sludge were slightly filled up to compare their growth rates.The results showed thatplanting seedlings with attached rhizomes had the best growth rate and without seedling death at 14 months after plant-ing.At this stage,however,the height of seedlings grown from the fallen fruits was similar to those growth from barerooted seedlings(70 cm tall).Also,seedling mortality was not observed when growth from fallen fruits whereas about6% mortality was experienced by the bare rooted ones.Among the bare rooted seedling treatments,however no signifi-cant differences in growth rates were found when applying the soil with chemical fertilizers or farm manure or liming withCaCO3.In addition,it was found that seedling growth measured at 40 months after planting for those growths in pondbase was almost100% greater than those grown on the furrows.Therefore,this finding may be applied for the restorationof abandoned shrimp ponds by growing Nipa palm.

Supplement and Consumption of Dissolved Oxygen and Their Seasonal Variations in Shrimp Pond

On the basis of the research of DO budget or kinetics in shrimp pond, the main influence process of DO and its seasonal variations are quantitatively described through redividing the budget process and modifying the quantitative method of the process. The percentages of oxygen demand of various processes in the total oxygen demand are different in shrimp cultivation seasons. It is showed that the dissolved oxygen demand of mini-organisms is the major affected factor of DO in this environment and approximately accounts for 64.1～74.1% of the total oxygen demand. In the early period of shrimp culture, the dissolved oxygen demand of allotrophic bacteria degrading organic matters is much lower than that of phytoplankton respiration. But in the midterrn and later period, it is about 50% of the total oxygen demand because of the higher water temperature and more serious self-pollution. The dissolved oxygen demand of sediment is lower and just 19.1～28.8%, while the percentage of shrimp oxygen demand is lower. The effect of phytoplankton on DO in shrimp culturing water has dualism. One is the oxygen producing process of photosynthesis and the other is the oxygen consumption process of respiration. It is estimated that the dissolved oxygen demand of phytoplankton respiration is approximately one-fifth of the oxygen produced by photosynthesis under normal illumination conditions. The dissolved oxygen demand of al lotrophic bacteria degrading organic matters and the total oxygen demand of sediment increase 4 times and 1.7 times respectively from the early period to the midterm and later period.Obviously, the DO of culturing water can be also greatly improved by controlling the selfpollution of organic matters during shrimp culture.

A Study on the Contribution of Different Food Sources to Shrimp Growth in an Intensive Fenneropenaeus chinensis Pond

Stable isotope methods can be used to determine the food sources and prey items of aquatic organisms accurately and reliably. This study examined the relative contribution of artificial foods （the formulated feed and Arternia） and natural foods to shrimp growth in an intensive Fenneropenaeus chinensis pond by using carbon and nitrogen stable isotopes. The results showed that the nutrition utilization efficiency of the harvested shrimp was low, only 33.18% of feed nitrogen and 21.73% of feed carbon being converted to shrimp flesh, Our stable isotope results showed that the shrimp obtained nutrition for maximum growth from artificial foods, whose contribution was 93.5%, with the remaining attributed to the natural foods. However, there was 0.94t harvested shrimp derived from natural foods （the rest of 13.56t harvested shrimp derived from artificial foods） in lha intensive pond with a shrimp production of 14.50 tha^-1. Therefore, unit area shrimp production can be increased by increasing the contribution proportion of natural foods in intensive shrimp farming.

Heterosis and heritability estimates for the survival of the Pacific white shrimp(Litopenaeus vannamei) under the commercial scale ponds

The aim of the present study is to detect the potential of the base population from diallel crosses of eight introduced strains of the Pacific white shrimp（Litopenaeus vannamei） for improving the yield. Heterosis and heritability were estimated for pond survival at commercial farm conditions for the base population that included 207 full-sib families from a nested mating design by artificial insemination. Among all the hybrids,the heterosis ranged from –11.37%（UA1×UA2） to 20.53%（UA3×SIN） with an average of 0.953%. The results showed that more than half of the hybrids（51.85%） have negative heterosis for survival rate, but most of the hybrids with positive heterosis have high estimates. The high proportion of negative heterosis for survival rate reminders us that the survival trait also should be considered in the crossbreeding program to avoid yield decrease. However, high positive heterosis manifested in most of the hybrids for survival indicates the usefulness of these hybrids for improving the survival to obtain higher yield by crossbreeding in this breeding program. The heritability estimate for pond survival was 0.092±0.043 when genetic groups were included in the pedigree, and it was significantly different from zero（P〈0.05）. The results from this study also indicated that significant improvement for survival is possible through selection in L. vannamei.

海水垂向入侵问题研究进展

随着全球气候变暖,风暴潮在沿海地区的频率和强度均可能增长,由此引发的海水垂向入侵可能会造成大面积的含水层淡水咸化。同时,由人类活动引起的沿海虾塘咸水养殖规模日益增长,由此引发的咸水垂向入侵可能会导致沿海地区地下水水质及生态环境的恶化。虽然已有一部分学者在海水(咸水)垂向入侵的研究中取得了成果,但由于海水(咸水)垂向入侵过程复杂,其对地下水咸化及恢复规律依然有待深入研究。文章阐述了海水垂向入侵的危害及前人的研究办法,总结了他们的研究成果并得出了海水垂向入侵的影响因子,指出了洪水和养殖活动对沿海地区含水层的威胁。得出的结果如下:研究海水垂向入侵常用的方法包括室内试验和数值模拟;海水垂向入侵主要与地形地貌、含水层性质和水文气象条件有关;虾塘养殖等人类活动可能会成为垂向咸水入侵的潜在来源。建议未来在海水垂向入侵研究中将多种现场观测实验方法结合起来。数值模拟应注重与现场观测实验数据相互验证,模型简化的方式有必要仔细考虑。虾塘养殖等人类活动可能造成的垂向咸水入侵问题应更多地受到关注。

西施舌人工繁育研究

开展了西施舌人工繁育研究。以3~4龄西施舌为亲贝,采用“封闭育苗”模式进行浮游幼虫和稚贝的培育,采用“附着板+池底”附苗模式进行采苗。结果表明,亲贝经过诱导、授精和孵化,获总卵量4536.99万粒,受精率达到(87.01±2.57)%,获受精卵3947.63万粒。经过胚胎发育阶段至初期面盘幼虫(D型幼虫),获D形幼虫3631.41万粒,孵化率达到(91.99±3.46)%。浮游幼虫壳长生长速度(9.92±0.26)μm/d,壳高生长速度(10.19±0.41)μm/d,浮游幼虫的存活率(84.26±3.78)%。经12~17d,浮游幼虫完成附着变态,形成初期稚贝。经30 d的培育,获得(3.26±0.12)mm×(3.10±0.09)mm的出池稚贝617.34万粒,稚贝成活率(17.00±1.93)%。经过约45 d的培育,获得(2.15±0.07)cm×(2.04±0.03)cm的西施舌中培苗(幼贝)257.99万粒,中培成活率为(41.79±2.51)%。指出,“附着板+池底”附苗模式可以取得较好的采苗效果,“封闭育苗”模式适于作为西施舌从浮游幼虫至幼贝的培育模式。

北海市虾塘海水养殖对地下水环境的影响与保护对策研究

通过开展中国地质调查局“北部湾经济区南康盆地地下水资源潜力评价”项目,文章梳理出了北海市所在的南康盆地地下水成因以及拟采取的保护措施,结合北海市虾塘海水养殖等经济发展方式所造成的对周围地下水环境的污染影响,提出在规划选址、海水养殖场建设以及养殖场运营期方面的地下水保护对策及措施,对北海市今后经济发展与地下水环境保护具有切实的指导意义。

Effects of Rice-Fish Co-culture on Oxygen Consumption in Intensive Aquaculture Pond

Rice-fish co-culture has gained increasing attention to remediate the negative environmental impacts induced by intensive aquaculture. However, the effect of rice-fish co-culture on oxygen depletion has rarely been investigated. We constructed a rice-fish co-culture system in yellow catfish(Pelteobagrus fulvidraco) and freshwater shrimp(Macrobrachium nipponense) ponds using a new high-stalk rice variety, and conducted a field experiment to investigate the effect of rice-fish co-culture on water parameters and oxygen consumption. The results showed that rice-fish co-culture reduced the nutrients(total nitrogen, ammonia-N, total phosphorous and potassium) and the dissolved oxygen content in fish and shrimp ponds. However, they showed similar seasonal change of dissolved oxygen in the water of fish and shrimp ponds. Rice-fish co-culture reduced the total amount of oxygen consumption and optimized the oxygen consumption structure in pond. The respiration rates in water and sediment were significantly reduced by 66.1% and 31.7% in the catfish pond, and 64.4% and 38.7% in the shrimp pond, respectively, by additional rice cultivation. Rice-fish co-culture decreased the proportions of respiration in sediment and water, and increased the proportion of fish respiration. These results suggest that rice-fish co-culture is an efficient way to reduce hypoxia in intensive culture pond.

海水虾池弧菌生态归趋特征与调控策略

弧菌(Vibrio spp.)为水产养殖危害极大的常见优势致病菌,其生态调控势在必行。综合弧菌生态研究进展,分析硫代硫酸钠-柠檬酸盐-胆盐-蔗糖琼脂(TCBS)生态模型,发现弧菌生态归趋特征为嗜盐、嗜铁、较低碳氮比(5~10)、较低表面张力和中性至弱碱性环境与环境骤变。据此,虾池弧菌生态调控,在于缓解对虾环境应激,同时培育弧菌的营养竞争者,压缩病原弧菌生态位,塑造有利于对虾生长的生态环境。其调控策略包括:1)短效策略——通过添加小分子有机酸或能发酵为小分子有机酸的有机碳源,提高C/N,促进异养益生菌而抑制弧菌增殖;2)中效策略——构建有益微藻、异养益生菌、硝化细菌和光合细菌等共同主导的生物絮团微生态系统;3)长效策略——构建挺水性盐生植物、有益微藻、鞭毛虫和纤毛虫、异养益生菌、硝化细菌和光合细菌等共同主导的生态系统。在对虾发病情况下,虾池弧菌速效逆转策略为:先行速效无残留消毒,再行短效有机酸C/N调控,最后相继进行中、长效调控。

青虾高效养殖初探

近年来,因池塘老化和种质退化,徐州地区青虾亩产量下降,青虾养殖经济效益急剧下滑。简述徐州地区青虾养殖池塘状况,概述青虾养殖流程。针对青虾养殖过程中存在的主要问题,提出引进优质苗种、采取套养模式、合理用药、采用轮捕与集中捕捞相结合等对策。

高效好氧反硝化盖氏假单胞菌YZ-7的鉴定及其脱氮性能研究

【目的】筛选出高效好氧反硝化细菌,开发出适宜在虾塘应用且具有强脱氮能力的新菌株,以解决虾塘因氮素含量过高引起的水体富营养化等问题。【方法】采用稀释涂布法和Giltay鉴别培养基从稻虾养殖塘的污水污泥中分离筛选高效脱氮菌株,结合形态学特性、生理生化特征和16S rDNA序列分析对分离菌株进行鉴定;测定分离菌株在KNO3氮源条件下的脱氮效率,同时分析不同环境因子对分离菌株反硝化能力的影响,并通过模拟试验评价其在处理虾塘养殖废水时的反硝化性能。【结果】从稻虾养殖塘污水污泥中分离获得1株高效脱氮菌,经形态学特性、生理生化特征和16S rDNA序列分析鉴定为盖氏假单胞菌(Pseudomonas gessardii),命名为YZWF2207(简写为YZ-7)。以KNO3为唯一氮源时,菌株YZ-7经过6 h的迟缓期后进入对数生长阶段,且菌株YZ-7生长速率与含氮物质的去除速率密切相关。以柠檬酸钠为唯一碳源时,菌株YZ-7对硝态氮(NO_(3)^(-)-N)的去除率为99.05%;碳氮比(C/N)范围为4.42~5.00时,菌株YZ-7具有较高的NO_(3)^(-)-N去除率(99.71%~99.85%);菌株YZ-7的最高NO_(3)^(-)-N去除率与生物量最大值并不同步,其更适宜生活在弱碱性(p H 7.0~8.0)环境中;菌株YZ-7的适宜环境温度为30℃,但在低温(15℃)下也能高效率完成反硝化过程,NO_(3)^(-)-N去除率可达79.41%。菌株YZ-7对虾塘养殖废水中的NO_(3)^(-)-N去除效果极显著(P<0.01),且积累的亚硝态氮(NO_(2)^(-)-N)相对于对照组有明显下降趋势。【结论】从稻虾养殖塘污水污泥中分离获得1株反硝化能力强的盖氏假单胞菌(YZ-7),其实现最佳好氧反硝化性能的碳源为柠檬酸钠,C/N为4.42~5.00,pH为7.0~8.0,温度为30℃。菌株YZ-7在养殖废水处理方面具有较强的反硝化能力和竞争优势,作为好氧反硝化细菌在富氮养殖废水的脱氮生物产品研发中具有广阔应用前景。

对虾海水池塘养殖固形废弃物集污效率以及尾水处理研究

为加快推进水产养殖业绿色发展,解决对虾海水池塘养殖面源污染以及产业发展与生态保护之间矛盾,研究了对虾海水池塘养殖固形废弃物集污效率与尾水生态处理技术。采用自行设计的沉淀塔进行固废收集,三级上向垂直流处理桶利用硝化-反硝化-再硝化处理工艺进行尾水脱氮处理。结果显示,在对虾池塘实际养殖过程中,养殖前期、中期与后期,沉淀塔对固形废弃物集污效率分别为10.6%±1.8%、31.1%±5.7%、52.2%±5.2%;总氮集污效率分别为1.4%±0.2%、3.4%±0.6%、9.1%±0.1%。三级上向垂直流处理桶均装填生物毛刷,自然挂膜60 d后,分别进行溶氧控制30 d,溶氧质量浓度分别为1.11~1.98 mg/L、0.27~0.45 mg/L、4.60~5.82 mg/L。经测定分析,三级处理桶总氮、氨氮去除率可以达到45.5%与93.6%,将处理桶中的毛刷进行高通量测序分析,发现第三级处理桶中硝化细菌丰度最高,主要包括亚硝化单胞菌属(Nitrosomonas)、亚硝化螺菌属(Nitrosospira)、硝化螺菌属(Nitrospira)。本研究构建了“沉淀塔固废集污”+“三级上向垂直流处理桶”模式,为对虾海水池塘养殖产业转型升级提供技术和模式参考。

基于邻域粗糙集的气象因子选择在虾塘水温预测中的应用

基于邻域粗糙集对影响虾塘水温变化的气象因子进行选择,并选取模型预测虾塘水温,为南美白对虾养殖趋利避害提供科学参考。首先,将平均气温、最高气温、最低气温、降水量、气压、2 min风速、10 min风速和瞬时风速等8个气象因子组合输入SFNN模型(单隐层前馈神经网络模型)、高斯回归模型和岭回归模型进行虾塘水温预测,选取预测效果最好的SFNN模型为本研究预测模型。然后,运用邻域粗糙集和熵理论,考虑气象因子和虾塘水温之间的相关性、冗余性和交互性,选出影响虾塘水温变化的主要气象因子。最后,利用选出的主要气象因子和SFNN模型实现虾塘水温预测。将基于邻域粗糙集选出的5个气象因子组合与8个气象因子组合,以及8个气象单因子分别输入SFNN模型,预测结果表明:邻域粗糙集选出的5个气象因子组合预测结果最好,其预测均方根误差、均方误差、平均绝对误差最小,分别为1.1211、1.2569和0.8938,决定系数(R2)为0.7916;在气象单因子中,气压对虾塘水温的预测结果较好。因此,基于邻域粗糙集选出的5个气象因子组合,通过SFNN模型进行虾塘水温预测结果最好,此方法在南美白对虾养殖趋利避害、防灾减灾中具有一定的实用价值。

青虾养殖池塘晒塘期间底质营养盐状况研究

青虾是江苏省传统淡水养殖的经济虾种之一。为探索其池塘养殖晒塘期间底质营养盐的变化情况,对其底质中总氮(TN)、总磷(TP)、氨氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(+)-N)、有机质(OM)5个指标进行检测。结果表明,青虾池塘在晒塘阶段底质变化明显,晒塘后青虾池塘底质中TN、TP、NH_(4)^(+)-N、NO_(3)^(+)-N、OM消减率分别为43.11%、26.21%、47.44%、39.78%、35.86%,对TN、NH_(4)^(+)-N的消减效果明显。

虾蟹混养池塘中微生物群落结构及抗性基因

为比较不同种类三疣梭子蟹与脊尾白虾混养池塘中环境微生物的种类、丰度及群落结构差异,综合水质监测、宏基因组测序等方法对不同类型养殖池塘的理化参数、微生物多样性以及抗性基因进行比较分析。结果表明,在整个养殖周期中,环境微生物在门水平上均以变形菌门为主,其相对丰度最高。此外,微生物多样性和功能基因比较分析显示,不同种类三疣梭子蟹混养池塘中微生物种群相对丰度存在差异,且对应的优势功能基因也存在差异,总体上以参与新陈代谢功能为主。环境抗性基因时空比较分析结果显示,养殖水环境中抗性基因在养殖早期阶段主要为磷酸乙醇胺转移酶MCR,中后期为β型-内酰胺酶,在养殖全周期底泥环境中,内氟喹诺酮类和四环素为相对丰度最高的抗性基因。对虾蟹混养池塘环境微生物的多样性、结构组成等进行研究,可为三疣梭子蟹优质种苗的选择、人工养殖管理技术等提供理论依据,推动水产养殖可持续性发展。研究养殖水体中ARGs的分布、丰度和变化对水质评价和污染控制具有重要意义。

河蟹、青虾、鱼的池塘高效混养技术

文章介绍了安徽省芜湖市镜湖区利用池塘养殖河蟹、青虾和各类鱼的混养方法,对池塘整理、轮放种苗、饲养管理、水质调控、鱼病防治、适时捕捞等技术手段进行了全面总结,并进行了经济效益和生态效益分析,对水产养殖者可起到借鉴作用。

海水养殖沉积环境微生物总DNA的提取方法研究

传统的微生物分离与培养技术：无法揭示微生物群落的动态变化．为了阐释虾池沉积环境微生态格局的原始组成情况，本研究先以TENP缓冲液去除沉积物中的腐殖酸。继之以溶菌酶-SDS温和裂解，其总DNA的提取效率达90％以上．所获DNA产量达2～20μg／g沉积物（湿），片段大小均在23kb左右，不经纯化即可直接进行PCR扩增和限制性酶切．以该DNA为模板进行PCR—DGGE分析，揭示了虾池沉积物丰富的微生物多样性，该方法是一种适用于虾池沉积物总DNA提取的简便、可靠方法．

厦门杏林虾池夏冬季微型浮游动物对浮游植物的摄食压力

20 0 0年 8月和 2 0 0 1年 2月 ,在杏林虾池用稀释法研究了微型浮游动物对浮游植物的摄食压力 .结果表明 :砂壳纤毛虫、甲壳类无节幼体是微型浮游动物的优势种 ;浮游植物生长率夏季为 0 .40～ 1 .0 1 /d、冬季为 0 .1 8～ 0 .96/d ;浮游动物的摄食率夏季为 0 .578～ 1 .3 2 4/d、冬季为 0 .2 0 4～ 0 .2 55/d ;日摄食率 (以C计 )夏季为 1 9.1 7～89.51mg/(m3·d)、冬季为 3 .3 2～ 7.2 3mg/(m3·d) ,各占浮游植物现存量的 43 .90 %～ 73 .40 %、1 8.43 %～ 2 2 .51 %;对初级生产力的摄食压力夏季为 1 1 5.2 3 %～1 93 .52 %、冬季为 3 7.47%～ 1 1 1 .3 1 %.

对虾池不同综合养殖系统效率和效益的比较研究

利用５０个５．０×５．０×１．８ｍ陆基围隔研究了中国对虾与台湾红罗非鱼、海湾扇贝和缢蛏投饵或施肥混养及鲈鱼与中国对虾和台湾红罗非鱼混养最佳结构的生态效率、生产效果和经济效益。结果表明，几种综合养殖系统最佳结构下各种养殖对象对Ｎ的绝对利用率由高至低依次为：鲈鱼－对虾－罗非鱼（３０．９１％）＞对虾－海湾扇贝（２１．０９％）＞对虾－罗非鱼施肥混养（２０．１２％）＞对虾－罗非鱼投饵混养（１７．８１％）＞对虾－缢蛏（１６．９３％）＞单养对虾（１１．５２％）；对Ｐ的绝对利用率由高至低依次为：对虾－缢蛏（１６．０８％）＞鲈鱼－对虾－罗非鱼（１２．８３％）＞对虾－罗非鱼投饵混养（１２．６３％）＞单养对虾（１０．８８％）＞对虾－海湾扇贝（６．０１％）＞对虾－罗非鱼施肥混养（４．０４％）；其产出投入比由高至低依次为：对虾－罗非鱼投饵混养（１．９９）＞对虾－罗非鱼施肥混养（１．９８）＞对虾－海湾扇贝（１．５３）＞单养对虾（１．３８）＞鲈鱼－对虾－罗非鱼（１．３０）＞对虾－缢蛏（１．２３）。