唐海县虾池赤潮生物种类与赤潮类型的研究

1989～1992年,我们对唐海县虾池赤潮生物种类与赤潮类型进行了研究。共发现赤潮生物21种,赤潮类型4种(单相型、双相型、三相型和四相型)。研究结果表明:发生在该县虾池中的绝大多数赤潮为多相型赤潮。     

池塘养殖水体不同水层水质变化研究

为探讨池塘养殖水体时间和空间上的变化特征,在上海市标准化养殖池塘里进行了水质参数监测和分析,研究了池塘上层、中层、下层不同水层的水质变化情况。结果表明:一年中池塘水质呈季节性变化,氨氮均值在9—11月最高,在5月份最低;溶氧均值在9—11月最低,在12月至次年3月最高;pH无明显季节性变化。不同水质参数日变化研究发现,一天中氨氮值在6:00左右最高,在17:00左右最低;溶氧最高值出现在15:00—17:00,最低值在5:00左右;pH在1:00最低,14:00左右最高。养鱼池塘水体有较明显的分层现象,上层、中层、下层不同水层的氨氮、溶氧、pH均有差异。一天中氨氮与溶氧总体呈负相关性(t<0.05),溶氧值升高时氨氮值下降。     

气升式光生物反应器培养微藻溶氧和pH值变化规律研究

为了解决在光生物反应器养殖微藻过程中,溶解氧和pH值2个培养工艺参数的控制问题,分别在80 L、350 L和900 L的3种规格气升式光生物反应器中培养湛江等鞭金藻(lsochrysis zhanjiangensis),高藻细胞浓度分别达到900×104,700×104,500×104cell/mL,测定其中溶氧和pH值的日变化。结果显示,在光照度4 000 lx以上时,湛江等鞭金藻光合作用强,表现为反应器中藻液溶氧较高,日最高溶氧分别可达17.91 mg/L、15.84 mg/L和12.7 mg/L。所测定的藻液日pH值均在7.00~9.16变化。     

鱼种越冬池的水质管理

水质是影响越冬鱼种成活率的关键因素之一,应着重抓好pH值和溶氧两个水质指标的管理。1 PH值 pH值是表示水体酸碱度的一个指标,鱼类越冬池的水体pH值要求在7—8之间,过高或过低对鱼类都有直接危害。生产实践表明,管理不善,越冬鱼种池水体pH值一般偏低。对此,可采取以下两项管理措施:(1)挂石灰袋。在日常管理监测中,倘若发现pH值下降较快,     

稻-金鱼共栖生态系统的水质理化性质分析

稻田养金鱼能显著提高稻田溶氧水平．其目变化规律与水温呈正相关关系．在14～16时达到最高值，凌晨5时左右稻田溶氧值达到最低值；水中NH4^ 浓度较对照组要高；S^2-的浓度两者均在18点时最低．凌晨4点时时最高．但稻一金鱼处理组比对照组S^2-浓度稍低；pH值与水温呈正相关关系，在14：00左右pH值最高，在凌晨06：00最低，稻-金鱼处理组pH值比对照组稍为降低．     

中国对虾养殖池水中溶解氧与透明度之间的关系

本文探讨了中国对虾(Penaeus chinensis)养殖过程中池水透明度和溶解氧的变化过程,以及影响这些变化的一些因素,并从虾池溶解氧～透明度曲线中得知,为保证虾池溶解氧水平,尤其是清晨池水中的溶解氧不低于4mg/L,池水透明度应以38～58cm为宜。     

三种微生态制剂对鱼池水质净化作用的对比试验

对比了三种微生态制剂对淡水养殖池的水质净化效果。试验结果表明：在提高水体的溶氧量方面，“高浓缩光合细菌”的效果极显著，比对照组提高了30％。“水产EM原液”和“益生菌”对水体的溶氧量无明显影响；在降低氨氮含量方面，“水产EM原液”和“益生菌”效果极显著，比对照组分别降低了82％，和81％。“高浓缩光合细菌”效果较显著，比对照组降低了69％；在提高池水的pH值方面，“水产EM原液”作用明显，较对照组提高4％，且不引起pH值剧烈波动。“高浓缩光合细菌”和“益生菌”对pH值的影响不明显；在降低池水的化学耗氧量方面，三种微生态制剂均未表现出显著作用。     

视觉·赤潮

赤潮，又称有害藻华。是指海洋中某些浮游藻类或原生动物等在一定环境条件下暴发性增殖或聚集达到某一水平，引起水色变化或对其他海洋生物产生危害作用的一种异常自然现象。目前，世界上已鉴定的赤潮生物隶属于10个门类。其中浮游植物约330种。据不完全统计，我国沿海赤潮生物有140余种，其中30多种在我国海域形成过有害赤潮。赤潮对海水养殖业造成严重危害。     

精养高产鱼塘水质调控技巧

1几种主要水质指标对池鱼的影响溶氧溶氧是鱼类赖以生存的必要条件,也是判断水质好坏的重要指标。池水溶氧高,可以抑制和减轻氨氮、亚硝酸盐、硫化氢对鱼类的毒害作用,提高鱼类食欲和饵料利用率,促进鱼类发育生长加快。而溶氧含量少,是造成水质变坏的重要原因,同时溶氧直接关系到鱼类的生存。鱼类健康生长对水体溶氧的要求为5毫克/升以上。pH值pH值是池塘水质的一个重要指标,它直接影响水体生态环境中各种化学和物理变化。pH值的降低或升高,对鱼类有直接的损害,可使鱼的鳃组织遭到破坏,引起鱼中毒,无力调节渗透压,降低血液载氧能力,使鱼因…     

淡水小棚养殖南美白对虾试验

<正>南美白对虾养殖过程中池水的温度、盐度、pH值、溶解氧以及营养盐的含量等各项指标对养殖产量的提高有极大影响。铵盐与亚硝酸盐对南美白对虾均有致毒作用。因此,了解并提高养殖过程中虾池水质是非常必要的。该文为2016年在营口天时水产公司进行的淡水小棚养殖南美白对虾试验结果,并对南美白对虾淡水养殖过程中对虾池的水质进     

Effect of Water Exchange and Mechanical Aeration on Grow‐out of the Amazon River Prawn in Ponds

Exchange and aeration of pond water are common practices in semi‐intensive freshwater prawn culture, but there is lack of scientifically based information on the results. We evaluated the effects of water flow through the ponds and mechanical aeration in semi‐intensive cultures of Macrobrachium amazonicum. A total of 40 juveniles/m² were stocked for 4 mo in 12 earthen ponds. Four randomly assigned treatments were applied: no aeration + no water exchange (NN), diurnal aeration + no water exchange (DA), nocturnal aeration + no water exchange (NA), and continuous water flow (CF). Temperature, pH, total suspended solids, and soluble orthophosphate in the water column did not differ among treatments. Dissolved oxygen (DO) concentrations in ponds with nocturnal aeration were significantly higher than in other treatments. The concentration of inorganic nitrogen was significantly higher in the CF treatment, whereas organic nitrogen was higher in treatments NN, DA, and NA. This suggests that primary production is higher in static ponds. Thermal stratification started at 0900 h, and the maximum difference between surface and bottom temperature varied from 1.5 (CF) to 2.8 C (NN). The difference between DO levels in the surface and bottom water of the ponds began to appear at 0800 h and varied from 0.50 (CF) to 5.23 mg/L (NN). Diurnal aeration and high continuous water flow were efficient in disrupting the stratification. No significant difference was found for survival, mean weight, apparent feed conversion rate, and productivity among treatments. Thus, disrupting water stratification, aerating ponds at night, or exchanging the pond water are ineffective in Amazon River prawn farming in semi‐intensive systems, at least for stocking densities lower than 40 individuals/m². About 1000 kg of Amazon River prawn can be produced in static ponds with no aeration in approximately 4 mo. This management strategy saves water and energy and reduces production costs .     

Effects of Two Densities of Caged Monosex Nile Tilapia, Oreochromis niloticus, on Water Quality, Phytoplankton Populations, and Production When Polycultured with Macrobrachium rosenbergii in Temperate Ponds

The effects of different densities of caged Nile tilapia, Oreochromis niloticus, on water quality, phytoplankton populations, prawn, and total pond production were evaluated in freshwater prawn, Macrobrachium rosenbergii, production ponds. The experiment consisted of three treatments with three 0.04‐ha replicates each. All ponds were stocked with graded, nursed juvenile prawn (0.9 ± 0.6 g) at 69,000/ha. Control (CTL) ponds contained only prawns. Low‐density polyculture (LDP) ponds also contained two cages (1 m³; 100 fish/cage) of monosex male tilapia (115.6 ± 22 g), and high‐density polyculture (HDP) ponds had four cages. Total culture period was 106 d for tilapia and 114 d for prawn. Overall mean afternoon pH level was significantly lower (P ≤ 0.05) in polyculture ponds than in CTL ponds but did not differ (P > 0.05) between LDP and HDP. Phytoplankton biovolume was reduced in polyculture treatments. Tilapia in the LDP treatment had significantly higher (P ≤ 0.05) harvest weights than in the HDP treatment. Prawn weights were higher (P ≤ 0.05) in polyculture than prawn monoculture. These data indicate that a caged tilapia/freshwater prawn polyculture system may provide pH control while maximizing pond resources in temperate areas.     

杂交青虾“太湖1号”与日本沼虾养殖性能的比较

试验以肥满度、平均规格、饲料系数、生长速度等生长性能指标,pH值、溶解氧、氨态氮、亚硝态氮等水质指标为依据,比较"太湖1号"F1及F2代与日本沼虾的生长性能。结果显示,饲料系数从低到高依次为:"太湖1号"F1<日本沼虾<"太湖1号"F2,其中F1和F2差异显著(P<0.05)。平均规格及上市成虾比例从高到低依次为:"太湖1号"F1>"太湖1号"F2>日本沼虾,其中F1代显著高于日本沼虾(P<0.05)。"太湖1号"的肥满度与日本沼虾差异不明显。9—10月吃食旺盛季节,杂交青虾"太湖1号"的体质量与体长均高于日本沼虾,其中,F1代达到显著水平(P<0.05),但体质量与体长的瞬时增长率优势不明显。9—10月份"太湖1号"F1养殖池的氨态氮、亚硝态氮等水质指标显著低于F2和日本沼虾池,而溶解氧与pH值的差异不大。养殖效益分析表明,尽管杂交青虾的增产优势不明显,但因其规格大,销售价格高,其产值与净利润仍高于日本沼虾,且F1代达到显著水平(P<0.05)。所以,杂交青虾"太湖1号"F1代的养殖性能显著优于日本沼虾,但F2代的生长优势不明显。     

潮间带潜堤网栏养虾设施的设计

在近岸潮间带建设潜堤,并在堤顶设置拦网是一种新型的对虾人工养殖设施。这种潜堤网拦养殖设施,在涨潮时,海水越堤而过,注入池内;退潮时,利用拦网防逃,潜堤贮水,实现自行换水。该设施投资小,节省能源,管理方便,产量高。本文通过两个已建工程的设计,说明这种养殖设施的可行性,并提出潜堤和拦网设计中的各项参数的确定方法。     

A Survey of Water Quality Characteristics of Effluent from Hawaiian Aquaculture Facilities

Ten water quality parameters were measured in influent and effluent water at 11 aquaculture facilities in Hawaii. The data were grouped into four categories based on the types of organisms cultured: freshwater fish, freshwater prawn, marine fish, and marine shrimp. Within each category, concentrations of most parameters were lognormally distributed and spanned one to two orders of magnitude. Geometric mean concentrations of suspended materials, total nitrogen, total phosphorus, and pigments were highest in effluent from freshwater prawn ponds and lowest in marine fish pond effluent. Nitrate/Nitrite and total ammonia concentrations were higher in fish pond effluent than in crustacean pond effluent. Parameter concentrations were generally higher in effluent than in influent water, with freshwater fish and prawn ponds exhibiting the greatest increases in suspended materials and pigments. In contrast, nitrate/nitrite concentrations were lower in effluent than in influent waters. These data provide a basis for analyzing the environmental impacts of warm-water aquaculture effluent discharges.     

４种微生态制剂对虾池水质及青虾生长性能的影响

在测定养殖水体pH值、溶解氧、氨态氮、亚硝态氮等水质指标和养殖青虾肥满度、平均规格、饲料系数等生长性能指标的基础上,比较研究了全池泼洒复合芽孢杆菌、EM菌、类球红细菌、超浓缩光合细菌微生态制剂对养殖水质的改善情况及提高杂交青虾"太湖1号"生长性能的效果。结果表明,4种微生态制剂均可改善水质;其中,芽孢杆菌与EM菌具有较强的降亚硝态氮功能,类球红细菌和EM菌具有较强的降氨态氮作用。4种试验菌剂的调水效果排序为:类球红细菌>EM菌>复合芽孢杆菌>超浓缩光合细菌。4种菌剂不同程度提高了青虾的生长性能;其中,类球红细菌效果最为显著,其次为EM菌、复合芽孢杆菌,而光合细菌的效果不显著。     

诱发三都湾海域赤潮的原因探讨

2012年4月23日三都湾海域爆发赤潮,爆发时间长达16d,主要是由血红哈卡藻(Akashiwo san-guinea)为优势藻种引起的。本文通过对三都湾海域大黄鱼种质资源养殖基地的海水进行分析,来探讨此次赤潮的原因。结果发现,在发生赤潮前期水温急剧上升,从11.80℃升至21.20℃,赤潮发生时的水温维持在16.40～21.20℃之间;盐度呈现下降状态,从25.12‰降至23.30‰;pH呈现明显上升状态,从8.03升至8.25;营养状态指数E值维持在1.6～9.2之间,长期属于富营养化状态。本研究结果表明,本次赤潮发生与水温、盐度、pH以及水体富营养化等密切相关。     

The potential of mixed culture of genetically improved farmed tilapia (Oreochromis niloticus) and freshwater giant prawn (Macrobrachium rosenbergii) in periphyton-based systems

The production performance of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) in periphyton‐based systems were studied in farmers' ponds at Mymensingh, Bangladesh. Fifteen ponds (200–300 m² area and 1.0–1.5 m in depth) were used to compare five stocking ratios in triplicate: 100% GIFT, 75% GIFT plus 25% prawn, 50% GIFT plus 50% prawn, 25% GIFT plus 75% prawn and 100% prawn. Ponds were stocked at a total density of 20 000 GIFT and/or prawn ha^?1. Bamboo poles (mean diameter 6.2 cm and 5.5 pole m^?2) were posted in pond bottoms vertically as periphyton substrate. Periphyton biomass in terms of dry matter (DM), ash‐free DM and chlorophyll a were significantly higher in ponds stocked with prawn alone than in ponds with different combinations of GIFT and prawn. Survival of GIFT was significantly lower in ponds stocked with 100% GIFT (monoculture) whereas, that of prawn was significantly higher in its monoculture ponds indicating detrimental effects of GIFT on prawn's survival. Individual weight gains for both species were significantly higher in polyculture than in monoculture. The highest total fish and prawn yield (1623 kg GIFT and 30 kg prawn ha^?1) over 125–140 days culture period was recorded in ponds with 75% GIFT and 25% prawn followed by 100% GIFT alone (1549 kg ha^?1), 50% GIFT plus 50% prawn (1114 kg GIFT and 68 kg prawn ha^?1), 25% GIFT plus 75% prawn (574 kg GIFT and 129 kg prawn ha^?1) and 100% prawn alone (157 kg ha^?1). This combination also gave the highest economic return. Therefore, a stocking ratio of 75% GIFT plus 25% prawn at a total density of 20 000 ha^?1 appeared to be the best stocking ratio in terms of fish production as well as economics for a periphyton‐based polyculture system.     

东海1972年一次毛丝藻赤潮的分析

1972年8月至11月于东海北部(30°N—32°N,127°E以西)部分海域中所出现的赤潮是由蓝藻门中的三种毛丝藻组成,即(1)汉氏毛丝藻 Trichodesmium Hildebrandtii Gomont(2)薛氏毛丝藻 Trichodesmium Thiebautii Gomont(3)红毛丝藻 Trichodesmium erythraeum Ehr.。其中汉氏毛丝藻为优势种。这次赤潮主要形成于长江口以东外海,9月份后虽扩大分布区,但仍以东部海区最密集。11月后逐渐消失。此次赤潮最明显的危害表现在对饵料基础的破坏上,它能引起鲐、鲹鱼索饵渔场位置的改变和洄游路线的变化,从而促成减产。经分析,此次形成赤潮的原因主要是由于由该年夏季气旋而引起的涌升流和连续的强台风等因素的综合作用结果。以使上、下层搅拌剧烈,营养盐充分溶于水中增加了肥沃度。加上秋季水温偏高和高温水体的出现,也为热带性藻类繁殖提供了有利条件。本文作者建议,今后随着现代工业的发展,应加强对海洋污染和赤潮预报的研究。