不同模式对虾养殖的自身污染及其环境效应

对虾养殖污染主要来源于过量的饵料,对虾排泄物、粪便和生物遗骸溶出或分解产生的N、P营养盐和有机质,以及在养殖过程中所投放的化学或抗生素类药物残留。本文根据有关调查和研究的资料,阐述对虾养殖自身污染的机制,着重分析目前我国南方较为普遍的高位池和低位池对虾养殖模式的特点与自身污染的关系及其环境效应,并提出针对这两种养殖模式的污染防治对策。     

亚热带河口养殖塘沉积物有机碳矿化及其影响因子

亚热带河口的养殖塘是温室气体二氧化碳(CO2)的重要排放源,但其沉积物有机碳矿化动力学特征目前尚未厘清.以我国东南沿海亚热带闽江、木兰溪以及九龙江河口区的6个凡纳滨对虾(Penaeus vannamei)养殖塘为研究对象,对沉积物取样,并进行为期60 d的室内厌氧培养,对养殖塘沉积物CO2累积产量曲线利用一阶动力学模型...     

我国湖泊与海水鱼类养殖的环境效应和基于生态系统的渔业管理

在我国,鱼类养殖是一项重要的商业活动。鱼类养殖在过去几十年的快速发展过程中,对水环境产生了重要影响。研究表明:鱼类养殖对养殖区鱼、浮游生物、水生植物群落结构和水质变化有重要影响。现在,几乎所有的鱼类养殖系统都在一定程度上受到了损害。随着人们环境保护意识的增强,鱼类养殖的环境效应和渔业管理问题已引起了社会的广泛关注,渔业管理不再仅仅是通过开发资源以获取最高产量。面临挑战,人们应该采取切实可行的步骤,从传统的渔业管理转变到基于生态系统的渔业管理,将渔业纳入生态系统管理以保障养殖业的可持续发展。     

冬季水鸟对崇明东滩水产养殖塘的利用

自然湿地的丧失和退化给依赖湿地生存的水鸟带来了严重威胁,人工湿地作为水鸟栖息地的功能日益受到关注.水产养殖塘是人工湿地的重要类型之一.通过研究崇明东滩水产养殖塘冬季水鸟群落组成及其栖息地特征,发现大面积养殖塘比小面积养殖塘吸引更多种类和更高密度的水鸟.养殖塘在放水前水位较高时吸引更多游禽栖息,而在放水后水位较低时吸引更多涉禽;在放水过程中,养殖塘中水鸟的种类最多,密度最大.另外,在放水的不同时期,不同的环境因子对水鸟群落的影响不同:放水之前,养殖塘水面面积和平均水深是水鸟种类和数量的主要影响因子,其中游禽种类和数量受水面面积影响较大,涉禽种类和数量受平均水深影响较大;放水过程中,裸地面积、芦苇面积、干扰程度、平均水深和水深变异对水鸟、游禽和涉禽的种类和数量起主要作用;放水之后,水深变异对水鸟种类和数量的影响较大,而影响游禽种类和数量的主要因子是水面面积,影响涉禽种类和数量的主要因子是水深变异.研究表明,通过对影响水鸟栖息地利用的主要因子的有效管理,养殖塘在提供经济效益的同时也能为水鸟提供适宜的栖息地.     

崩岗灾害地貌及其环境效应

全面论述了崩岗灾害地貌的分布、发育条件及其带来的环境效应,提出崩岗灾害治理的措施．     

崇明东滩越冬鸟类在养殖塘的空间分布

鸟类对空间的利用直接反映对栖息地的选择。通过对崇明东滩养殖塘越冬鸟类群落调查,运用空间自相关检验、空间插值分析和景观格局分析,研究越冬鸟类在养殖塘人工湿地的空间分布格局。结果显示:雁鸭类和鸻鹬类在养殖塘分布特征显著不同。雁鸭类呈现显著的空间自相关,为聚集分布,且丰富度和多度分布较为一致;而鸻鹬类在养殖塘以随机分布为主,丰富度显示一定的聚集分布。养殖塘已经成为崇明东滩越冬鸟类重要的栖息地,不同生态类群栖息地选择存在差异:芦苇植被发育好,水域面积较小且水深较深,不同斑块以聚集为特征的养殖塘是雁鸭类的适宜生境;鸻鹬类则偏好一定芦苇植被、水域面积大且水深较浅的养殖塘。因此在保护区土地利用和管理时应考虑不同生态类群对栖息地选择的差异。     

福建省兴化湾滨海养殖塘冬季水鸟的栖息地利用

20D7年12月至2008年3月对福建省兴化湾东北部江镜华侨农场(25°29′～25°33′N,119°23′～119°26′E)滨海养殖塘水鸟的栖息地利用进行了研究.选取了6个养殖塘作为样地,总面积360 hm2,共记录到水鸟6目8科25种.潮汐变化是影响养殖塘内越冬水鸟栖息的重要因素.高、中、低3种不同潮位下养殖塘水鸟群落特征差异较大.水鸟的种数和数量随潮水的涨高而显著增加,优势种则减少;多样性指数和均匀性指数随潮水的涨高而降低,优势度则增大.养殖塘的水深是影响水鸟栖息的另一个重要因素.4个不同水深区域水鸟群落的种类组成及密度差异显著,鸻鹬类、鸥类、鹭类等鸟类在中等水位区和浅水区栖息,鸭类主要栖息在深水区,而无水区仅有少数鹭类活动.在潮汛期间,滨海养殖塘是水鸟良好的临时栖息地,科学管理可使养殖塘人工湿地与潮间带滩涂共同满足越冬水鸟的栖息需求.     

快速城市化区域城市热岛及其环境效应研究

以广州为中心的珠江三角洲区域城市化十分迅速,城市热岛对城市生态环境影响极大。城市热岛及其环境效应的研究有利于城市合理规划和可持续发展。利用中尺度模式MM5模拟广州地区的城市热岛效应,模式采用四重嵌套网格,最高水平分辨率为1km。研究通过数值模拟结果与自动气象站观测的气温和ETM+热红外波段反演的地温的对比,表明该方案能准确模拟地表的温度状况和城市热岛的环境效应。研究还表明城市干岛与热岛相伴而生,02时和11时广州热岛强度较小,相对湿度较高,20时热岛强度达到最大,城区相对湿度则最低;因城市热岛的存在,改变了原盛行风向,减弱了风速,且湿地、绿地、河流廊道等景观分割了城市热岛和干岛,增加了其破碎度,调节了城市气候。     

华北地区冬小麦灌溉制度及其环境效应研究进展

充分利用有限的灌溉水资源确保冬小麦安全生产是华北地区冬小麦稳产高产面临的严峻挑战,解决这一问题的关键在于如何基于环境效应科学地进行灌溉管理。综述了国内外有关冬小麦的灌溉管理制度,即充分灌溉与非充分灌溉管理制度以及冬小麦关键灌溉期的环境效应,在此基础上提出了华北地区冬小麦科学灌溉拟重点关注的研究任务:(1)冬小麦生长发育需水时间与需水量的控制机制研究;(2)冬小麦干旱发生发展过程与致灾临界气象条件研究;(3)气候变化背景下极端干旱事件的冬小麦脆弱性诊断与适应性管理,以为华北地区冬小麦安全生产措施制定提供依据。     

大黄鱼池塘不同混养模式生态学特征比较

利用菊花江蓠、双齿围沙蚕和大黄鱼在陆基围隔中构建鱼+藻(FG)、鱼+藻+沙蚕(FGP)以及鱼+沙蚕(FP)3种复合养殖模式,以单养鱼(F)模式为对照,探讨不同模式系统的沉积物、水体环境状况、养殖效益及氮、磷元素的回收效率.结果表明:菊花江蓠主要作用于系统水体中氮和磷的净化,具藻处理中氮、磷含量均显著低于无藻处理,对于水体环境中磷的利用效率达到投入量的33.8%～34.0%;沙蚕作用主要体现在对沉积物环境的改善,具沙蚕处理中氮、磷含量低于不具沙蚕处理,且在沉积物表层(1～2 cm)和次表层(2～4 cm)差异均显著.相对于F处理,FGP及FP处理总氮(TN)、总磷(TP)和无机磷(IP)分别下降了8.9%～9.2%、6.1%～6.3%和8.0%～8.1%.沙蚕对于沉积物中磷的回收达到投入量的7.5%～7.8%,有效减缓了磷在沉积物中的积累.FGP系统具有最佳的物质利用率及资源效益.     

The environmental quality and social justice implications of shrimp mariculture development in Honduras

Development schemes aimed at reducing Central America's social and economic problems historically have stressed intensified exploitation of the region's natural resources through augmented exports of agricultural commodities and forest products, enhanced agricultural productivity, and expanded industrial fisheries. There is plentiful evidence documenting how succeeding waves of export expansion have displaced small farmers from their lands often initiating cycles of repression and violence while also generating or intensifying environmental destruction. This paper explores the environmental quality and social justice implications of the current prevailing development strategy in the region, the promotion of so-called nontraditional exports. Focusing on the expansion of shrimp mariculture in coastal zones along the Gulf of Fonseca, Honduras, it uses political ecological analysis to examine the interconnections among the dominant export-led development model, the policies and actions of the state, the competition among various classes and interest groups, and the survival strategies of an increasingly impoverished population. Analysis suggests that problems of social justice and environmental quality cannot be understood apart from the underlying social structure of the region.     

Change of enclosure in langur monkeys: implications for the evaluation of environmental enrichment

A group of Hanuman langurs (Presbytis entellus) was studied before and after it was moved from an old cage‐style enclosure to a novel naturalistic environment at the London Zoo. Eating and locomotion occupied more of the langurs' time in their new enclosure, whereas dozing, allogrooming, and aggression decreased, along with an increase in inter‐individual distances. These changes are attributed to the larger area, the stimulating new environment, and the langurs' increased distance from visitors. Nevertheless, the study raises questions about how to define standards of desirable environmental enrichment, as the activity patterns recorded in both the old and new enclosures are within the variation observed in the wild. Zoo Biol 21:549–559, 2002. © 2002 Wiley‐Liss, Inc.     

The present situation and problems of mariculture in Japan

Summary Recently, rearing techniques for various kinds of fish have advanced markedly, and the number of fish species in commercial production increases every year. The establishment of methods for stable, reproducible mass culture of live foods that are highly nutritious is still necessary to improve the survival and growth rates of larval fish. Since, however, the mass propagation of live foods requires costly equipment and depends upon weather conditions, the development of artificial larval diets to replace live foods will be essential. In mariculture local trash fish are commonly used as a feed for juvenile fish because of their low cost and high acceptability to the cultured fish. However, this frequently results in deterioration of water environments, leading to the appearance of fish diseases and pollution. The development of artificial diets such as moist pellets will also improve these conditions.Mass-cultured fish seed are mainly used for the culture of commercial-sized fish, even though they are generally poorer in taste than wild fish. They are also used for release into coastal waters to promote inshore fishery, but it is difficult to evaluate the effect of stocking on the total catch. Another type of mariculture depends upon raising wild juveniles, though there are clearly too few caught to supply enough fish seed to satisfy the ever-growing demands of fish breeders. Thus, the cultivation of broodstock to produce high-quality eggs is important.     

海水养殖生境中硫酸盐还原菌活性的抑制机制

【目的】海水养殖生境中的硫化物(H₂S)严重损害养殖生物健康,控制该条件下硫酸盐还原菌(sulfate-reducing bacteria,SRB)的代谢活性是有效抑制H₂S产生的重要途径。【方法】本研究利用稀释涂布-叠皿夹法对海水养殖生境底泥中SRB进行富集筛选,获得SRB菌株,通过投加硝酸盐对菌株产H₂S的活性进行抑制。【结果】获得的2株SRB Desulfovibrio sp.NY-1和Clostridium sp.NH-1,能够在35℃、pH为7.0及盐度为20–30 mg/L条件下,分别积累高达435和150 mg/L H₂S。硝酸盐不能有效抑制NY-1产H₂S的活性,基因调控作用以及缺乏将硝酸盐作为电子受体的酶体系是其不能被抑制的主要原因。硝酸盐对NH-1 H₂S产生活性有可逆性抑制,其具有硝酸盐异化还原成铵(dissimilatory nitrate reduction to ammonium,DNRA)的能力,优先利用硝酸盐作为电子受体。DNRA作用下的中间代谢产物亚硝酸盐是有效抑制菌株NH-1产H₂S活性的主要原因,其抑制机理主要为抑制菌株的生长繁殖。【结论】硝酸盐对不同SRB菌株具有不同的抑制机制和效果,在进行硫化物污染控制前需要对产生硫化物的SRB菌群进行分析判别。     

Geochemical signature of land-based activities in Caribbean coral surface samples

Anthropogenic threats, such as increased sedimentation, agrochemical run-off, coastal development, tourism, and overfishing, are of great concern to the Mesoamerican Caribbean Reef System (MACR). Trace metals in corals can be used to quantify and monitor the impact of these land-based activities. Surface coral samples from the MACR were investigated for trace metal signatures resulting from relative differences in water quality. Samples were analyzed at three spatial scales (colony, reef, and regional) as part of a hierarchical multi-scale survey. A primary goal of the paper is to elucidate the extrapolation of information between fine-scale variation at the colony or reef scale and broad-scale patterns at the regional scale. Of the 18 metals measured, five yielded statistical differences at the colony and/or reef scale, suggesting fine-scale spatial heterogeneity not conducive to regional interpretation. Five metals yielded a statistical difference at the regional scale with an absence of a statistical difference at either the colony or reef scale. These metals are barium (Ba), manganese (Mn), chromium (Cr), copper (Cu), and antimony (Sb). The most robust geochemical indicators of land-based activities are coral Ba and Mn concentrations, which are elevated in samples from the southern region of the Gulf of Honduras relative to those from the Turneffe Islands. These findings are consistent with the occurrence of the most significant watersheds in the MACR from southern Belize to Honduras, which contribute sediment-laden freshwater to the coastal zone primarily as a result of human alteration to the landscape (e.g., deforestation and agricultural practices). Elevated levels of Cu and Sb were found in samples from Honduras and may be linked to industrial shipping activities where copper–antimony additives are commonly used in antifouling paints. Results from this study strongly demonstrate the impact of terrestrial runoff and anthropogenic activities on coastal water quality in the MACR. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Communicated by Geology Editor Bernhard Riegl     

Development of mariculture and its impacts in Chinese coastal waters

China has a long history of aquaculture. Since the 1980s, mariculture has been considered by the government as an increasingly important sub-sector of aquaculture. Mariculture provides nutritional and economic benefits, and decreases the intensity of exploitation on declining wild living resources. China now has the highest mariculture production in the world. Kelp made up 50–60% the total Chinese mariculture production in 1967–1980. Production of Laminaria japonicaAresch, the leading species, reached 252, 907 t (dry wet) in 1980. The percentage of kelp production decreased after 1981 because of proportionally greater production of molluscs, shrimps and finfish. Marine finfish and mollusc production increased sharply after 1990. In 2001, the total mariculture production reached 11,315,000 t from a production area of 1,286,000 ha. The rapid development and changes in mariculture species have aroused increasing concern about maricultures impact on the coastal environment. The impact of coastal aquaculture, such as water quality deterioration and contaminants, will have a significant bearing on the expansion of mariculture. The key of improving and maintaining the long-term health of mariculture zones lies in adopting sustainable culture systems. It is imperative that the density of stocking fish and other economically important organisms such as oysters, and scallops, be controlled, in addition to restricting the total number of net-cages in the mariculture zones. The authors suggest moving rafts (cages) periodically and to development of a fallow system in which area fish culture will be suspended for 1–2 years to facilitate recovery of the polluted sediment. Moving fish culture offshore into deeper waters is also suggested. The authors also believe that large-scale seaweed cultivation will reduce eutrophication in coastal culture zones in China.     

Predicting the constraint effect of environmental characteristics on macroinvertebrate density and diversity using quantile regression mixed model

Various factors, such as habitat availability, competition for space, predation, temperature, nutrient supplies, presence of waterfalls, flow variability and water quality, control the abundance, distribution and productivity of stream-dwelling organisms. Each of these factors can influence the response of the density of organisms to a specific environmental gradient, inflating variability and making difficult to understand the possible causal relationship. In our study, we used quantile regression mixed models and Akaike’s information criterion as an indicator of goodness to examine two different datasets, one belonging to Italy and one belonging to Finland, and to detect the limiting action of selected environmental variables. In the Italian dataset, we studied the relationships among five macroinvertebrate families and three physical habitat characteristics (water velocity, depth and substratum size); in the Finnish dataset the relationships between taxa richness and 16 environmental characteristics (chemical and physical). We found limiting relationships in both datasets and validated all of them on different datasets. These relationships are quantitative and can be used to predict the range of macroinvertebrate densities or taxa richness as a function of environmental characteristics. They can be a tool for management purposes, providing the basis for habitat-based models and for the development of ecological indices.     

桑沟湾养殖生态系统健康综合评价

桑沟湾是我国北方以筏式养殖利用为主的典型海湾,来自养殖的压力对海湾生态系统和养殖自身的健康发展产生了影响.利用《海洋养殖生态系统健康综合评价:方法与模式》建立的方法,对桑沟湾这一养殖生态系统的健康进行了综合评价.结果表明:桑沟湾养殖生态系统受到中等程度的压力,主要来自较高的养殖密度、较大的养殖面积和陆源营养盐的输入;生态系统状态等级为较好,其中水交换、水体环境和底质环境均为较好;自然生物群落状态为中等;生态系统响应中的养殖病害问题和养殖产品质量问题为中等.总体评价,桑沟湾养殖生态系统健康勉强达到较好水平,控制养殖密度和规模等措施是改善桑沟湾生态系统健康的必要途径.