池塘养殖(青虾)生态系统服务价值的系统动力学模型

生态服务价值的评估在近10 a来受到广泛关注,但大多基于静态评估框架,缺少动态分析。研究运用系统动力学的原理和方法,分析了青虾池塘养殖生态系统服务价值评估系统的内部结构,描绘了因果关系图及流图,建立了相应的系统动力学模型,初步预测不同决策方案下食物供给、固碳、释放氧气价值和富营养化环境成本在30 a内的变化趋势,结果表明:①无论采取何种决策,若系统外部环境不变,生态系统净服务价值的供给趋于稳定;②在池塘养殖生态系统中,释放氧气和固定二氧化碳等非市场价值是生态系统服务价值重要稳定的来源;③青虾养殖中投资变动在短期内往往会造成水产品市场价值的大幅波动,长期里则因投入的增加而增加,但增加率逐渐减少,最终达到稳定值;④在当前条件假设和环境参数的约束下,模型模拟结果与实测结果基本一致。     

池塘河蟹生态养殖对水体环境的影响

为了评判河蟹生态养殖对周围水环境的影响,2004年4-11月对河蟹生态养殖池塘的水环境进行了现状调查与监测.水源区的水质主要超标项目为总氮、总磷、氨氮和高锰酸盐指数,表明水源区水质主要是富营养化和轻微的有机污染.在池塘生态养殖区中,水质主要超标项目为pH值和总磷.生态养殖区水质虽有超标,但超标幅度明显低于水源区.调查同时发现,河蟹生态养殖区因栽有大量的水草,对氮磷的吸收比较充分,故生态养殖区的氮磷在养殖周期中的变化较水源区要小得多,叶绿素A的动态变化也证明了水草的生态意义.总体而言,生态养殖区的水质要明显优于水源区,基本上达到地表水环境质量标准中的3级标准和渔业水质标准的要求.河蟹生态养殖不会对外界水环境产生不良影响.     

热带海水养殖清洁生产技术模式探讨

采用太阳光化学修复原理对典型热带地区--海南省某养殖场废水进行清洁闭环生态养殖技术初步探讨.采用现场定位观测实验研究方法,探讨高位池光化学循环净化装置对养殖废水中COD、SS等污染物的去除效应、脱氮解毒效应以及增氧效应等.结果表明,本实验装置能有效地实现热带地区高位池循环水养殖及养殖污水的"零排放",是满足环保要求的一种多功能、低成本、效果好的水体净化方法.     

Sea-Cage Aquaculture, Sea Lice, and Declines of Wild Fish

Abstract: A sea cage, sometimes referred to as a net pen, is an enclosure designed to prevent farm fish from escaping and to protect them from large predators, while allowing a free flow of water through the cage to carry away waste. Farm fish thus share water with wild fish, which enables transmission of parasites, such as sea lice, from wild to farm and farm to wild fishes. Sea lice epidemics, together with recently documented population‐level declines of wild salmon in areas of sea‐cage farming, are a reminder that sea‐cage aquaculture is fundamentally different from terrestrial animal culture. The difference is that sea cages protect farm fish from the usual pathogen‐control mechanisms of nature, such as predators, but not from the pathogens themselves. A sea cage thus becomes an unintended pathogen factory. Basic physical theory explains why sea‐cage aquaculture causes sea lice on sympatric wild fish to increase and why increased lice burdens cause wild fish to decline, with extirpation as a real possibility. Theory is important to this issue because slow declines of wild fish can be difficult to detect amid large fluctuations from other causes. The important theoretical concepts are equilibrium, host‐density effect, reservoir‐host effect, and critical stocking level of farmed fish (stocking level at which lice proliferate on farm fish even if wild fish are not present to infect them). I explored these concepts and their implications without mathematics through examples from salmon farming. I also considered whether the lice‐control techniques used by sea‐cage farmers (medication and shortened grow‐out times) are capable of protecting wild fish. Elementary probability showed that (where W is the abundance of wild fish, W* is the prefarm abundance, F is the abundance of farm fish, and is the ratio of lice per farm fish to lice per wild fish). Declines of wild fish can be reduced by short growing cycles for farm fish, medicating farm fish, and keeping farm stocking levels low. Declines can be avoided only by ensuring that wild fish do not share water with farmed fish, either by locating sea cages very far from wild fish or through the use of closed‐containment aquaculture systems. These principles are likely to govern any aquaculture system where cage‐protected farm hosts and sympatric wild hosts have a common parasite with a direct life cycle.     

盐碱湿地鲇鱼资源及其增养殖

鲇鱼是松嫩平原盐碱湿地重要的高值食用鱼类之一。根据近年来对新荒泡鲇鱼的研究,作者报道了其生物学特征、经济价值、资源利用现状及其对新荒泡渔业资源的影响,提出了鲇鱼的增养殖途径及其关键技术。     

我国水产在可持续发展中的贡献和问题

可持续发展是我国发展战略与国策,我国水产通过繁殖保护、增殖水产资源;发展与强化水产养殖,扩大与充分利用养殖水体;综合养殖,特别是渔业生态工程等高速大幅度增产多种水产品,提高人民生活水平,增加经济收入,促进一些物质的良性循环,从而对可持续发展有所贡献,但其中有些部分忽略了水产所依托的水生态系统的整体性、协调性和稳态,导致人与自然在某些方面失调,不利于可持续发展。本文着重从一些生态学方面分析这些贡献和问题,并举一些例证加以论述。     

生物活性炭填料反应器处理含盐水体的硝化性能

以颗粒活性炭为填料,采用盐度梯度两步驯化法构建含盐水体生物滤器硝化功能,研究了生物滤器稳定后水力停留时间(hydraulic retention time,HRT)、进水氨氮负荷和CODMn/N等对反应器硝化性能的影响。结果表明,25～27℃,盐度30的含盐水体生物滤器硝化功能构建需73 d,其中淡水生物滤器硝化功能构建需28 d,淡水驯化为盐度15的生物滤器需19 d,盐度15驯化为盐度30的生物滤器需26 d;实验条件下生物活性炭填料反应器中生物量达到146～742.1 nmolP/g-BAC;调节进水氨氮浓度2 mg/L左右时,最佳HRT为1 h,氨氮去除率达到84.98%,相应的氨氧化菌和硝酸菌氧吸收速率(oxygen uptake rate,OUR)分别为2.091和1.948 mg O2/(g-BAC.h);HRT为1 h时,随着进水氨氮负荷的加大,氨氮去除率逐渐降低,当进水氨氮负荷由0.12增加到0.48 g-N/(kg-BAC.d)时,氨氮去除率由84.98%降低到41.68%,同时氨氧化菌OUR由2.091降低到0.625 mg O2/(g-BAC.h);随着CODMn/N的升高,氨氮去除率下降,CODMn/N从1～8时,氨氮去除率由84.98%降低到53.64%,CODMn去除率却逐渐增加,由40.86%增加到93.59%,异养菌OUR随着CODMn/N升高呈上升趋势,最大达到0.914 mg O2/(g-BAC.h)。     

Refining Nitrogen and Phosphorus Fertilization Strategies for Controlling the Toxigenic Alga Prymnesium parvum1

Kurten, Gerald L., Aaron Barkoh, Drew C. Begley, and Loraine T. Fries, 2010. Refining Nitrogen and Phosphorus Fertilization Strategies for Controlling the Toxigenic Alga Prymnesium parvum. Journal of the American Water Resources Association (JAWRA) 46(1):170-186. DOI: 10.1111/j.1752-1688.2009.00401.x Abstract: Previous studies have shown that three times weekly applications of phosphorus (30 μg P/l) and nitrogen (300 μg N/l) were effective at reducing the density and toxicity of the alga Prymnesium parvum in limnocorrals simulating a 40-day moronid (e.g., striped bass, Morone saxatilis, and palmetto bass, M. saxatilis ×Morone chrysops) fingerling culture period. However, this fertilization regime produced high pH and unionized ammonia-N concentrations that are detrimental to the survival of moronid fry and fingerlings. In two follow-up experiments we changed the source of N from ammonia to nitrate, reduced fertilization rates, and examined the effect of N-only or P-only fertilization. In the first experiment P fertilization rates were reduced by one-half to 15 μg P/l and NO₃-N was substituted for NH₃-N at the previously used rate of 300 μg N/l. In the second experiment, N fertilization rates were reduced to 150 μg N/l and the frequency of fertilization was determined by pH and P. parvum responses. Nitrate appeared to be as effective as ammonia as a source of N and when used in combination with P reduced P. parvum cell density and ichthyotoxicity. However, reduced N and P application rates and lower pond water temperatures during the study appeared to have decreased the speed at which fertilization produced these effects. While lower fertilization rates reduced algal productivity, high pH remained a concern for fish culture although pH was reduced to levels that might be acceptable with careful management of fish culture activities. Neither N-only nor P-only fertilization had a measurable effect on algal productivity or eliminated P. parvum and its toxicity. Furthermore, P-only fertilization may have increased P. parvum density and toxicity. For controlling P. parvum density and ichthyotoxicity we recommend a fertilization rate of 212 μg NO₃-N/l plus 30 μg PO₄-P/l applied three times weekly for aquaculture ponds where high pH is not a concern. Where high pH is a concern we recommend a fertilization rate of 117 μg NO₃-N/l plus 16 μg PO₄-P/l applied three times weekly with careful attention to afternoon pond pH.     

养殖池塘生态系统中磷的收支及解磷微生物的研究进展

综述了池塘养殖系统磷的收支情况.研究发现,在池塘养殖系统中,磷输出最主要的形式为底泥沉积,养殖池塘中存在着磷的总体利用效率不高,水体中活性磷含量低的问题.而解磷微生物的应用在一定程度上可有效解决上述问题,它们能将植物难以吸收利用的磷转化为可吸收利用的形态.通过阐述解磷微生物的种类、解磷效果及解磷机制,结合养殖池塘的情况,分析了将解磷微生物应用于水产养殖中的可行性,并对今后的研究方向作出了展望.结合我国水产养殖的实际情况,筛选适应池塘养殖环境的高效解磷微生物,并将其应用于池塘养殖中,使池塘沉积物中难溶性磷转化具备相当的可行性.     

太湖地区的水资源与水环境——问题、原因与管理

太湖目前主要存在的问题是:①1998年太湖达标排放以来北太湖地区与梅梁湾的水环境没有如预期的那样得到显著改善;②太湖地区的洪涝问题并没有消除,相反随着经济的发展,其易损性增加;③东太湖的沼泽化与富营养化日趋严重,极大地降低了湖泊泄洪能力与供水能力。东太湖的沼泽化与富营养化与养殖业的无计划发展有很大关系,主要是管理所造成的。洪涝问题则是由于流域下垫面的急剧变化导致洪峰提前和洪峰流量增大。