水产养殖逃逸对长江外来种入侵影响:以鲟鱼为例

水产养殖逃逸有多种途径:直接逃逸为鱼类入侵生态学提供了独特的"天然实验"数据,而民间放生为水产养殖逃逸的主要间接途径,此外还包括观赏渔业的弃养等其他途径。以2016年清江流域外来种鲟鱼逃逸事件为例,探讨了逃逸后对长江外来种入侵影响,包括与土著种——国家一级保护动物中华鲟的竞争排斥、潜在杂交风险和养殖疾病传播等。在此基础上,讨论了通过网箱养殖的陆地工厂化和加强科普宣传使民间放生可能导致的降低生物多样性转化为科学放流的保存甚至提升生物多样性等预防措施,并指明了逃逸发生后续监管的方向,最后展望了水产养殖逃逸对长江外来种入侵影响评估的未来发展方向。     

广西内陆水域外来鱼类入侵风险分析

【目的】对广西内陆水域的外来鱼类进行入侵风险评估和适生区预测,为广西外来鱼类入侵防治及水生态环境保护提供科学依据。【方法】采用鱼类入侵风险和水生生物入侵能力筛查系统2个体系筛选广西内陆水域具有入侵风险的鱼类,并用最大熵模型预测高入侵风险鱼类在广西内陆水域的潜在适生区。【结果】广西内陆水域共记录有外来鱼类18种,其中13种鱼类具有高入侵风险,分别为尖齿胡鲇、尼罗罗非鱼、莫桑比克罗非鱼、奥利亚罗非鱼、豹纹脂身鲇、齐氏罗非鱼、大口黑鲈、斑点叉尾鮰、短盖肥脂鲤、露斯塔野鲮、条纹鲮脂鲤、麦瑞加拉鲮和食蚊鱼,2种具有中入侵风险,为丁鱥和太湖新银鱼。适生区预测结果表明,极易发生鱼类入侵的水域为黔江、郁江和南流江。【结论】对中、高入侵风险的鱼类均需重点监控且在具有高入侵风险水域应对外来鱼类开展持续性监测,并进行早期筛查。     

尖塘鳢属鱼类线粒体12SrRNA基因序列分析

利用PCR技术扩增和测序了线纹尖塘鳢、云斑尖塘鳢和海丰沙塘鳢线粒体12SrRNA基因,结合从GenBank中下载的部分同源序列,共分析了5种鱼类的系统发育关系。在Kimura2-parameter模型构建的邻接树中,原产泰国的云斑尖塘鳢与原产澳州线纹尖塘鳢均为单系类群,二者为亲缘关系最为密切的姐妹群,海丰沙塘鳢与其它群体的亲缘关系较远,支持将尖塘鳢属从塘鳢属中分出的传统分类处理。尖塘鳢属内云斑尖塘鳢和线纹尖塘鳢鱼类种内DNA序列无差异,而种间差异明显,表明线粒体12SrRNA基因可作为塘鳢科鱼类种类鉴定的良好分子标记。     

气候变化对全球马缨丹分布影响的空间模拟

【目的】马缨丹是世界10种最有害的入侵杂草之一,预测其潜在适生区变化对入侵植物防控具有重要意义。【方法】以马缨丹为研究对象,采用有效分布点数据1744份和10个气候因子,使用MaxEnt模型和ArcGIS10.4软件,选用当前气候情景以及2050sSSP126、2050sSSP245、2050sRCP5.8、2090sSSP126、2090sSSP245、2090sSSP585 6个不同气候情景,对马缨丹全球潜在分布区进行预测。【结果】温度和降水因子是制约马缨丹入侵的主要因子,其中年降水量(bio12,48.6%)、最干季度的平均温度(bio9,36.4%)、温度季节性(bio4,4.6%)和最热季度的平均温度(bio10,4.2%)是制约马缨丹分布格局的主要环境因子。南美洲、非洲南部、亚洲南部以及澳大利亚北部和东部具有较高的入侵风险。从当前气候情景到2050年气候情景再到2090年气候情景的过渡中,其适生区面积呈增加趋势,其中高适生区面积持续增加。【结论】在水热条件以及生物因素3个层面上严格防控马缨丹入侵,以增加土著生态系统的完整性。     

基于线粒体COⅠ基因鉴别云斑尖塘鳢和线纹尖塘鳢的分子标记

云斑尖塘鱼鳢(Qxyleotris marmoratus)原产于泰国、越南等东南亚国家线纹尖塘鳢(Oxyeletris lineolatus)原产于澳大利亚,目前两者已成为中国的养殖品种。由于其同属塘鳢属(Oxyeleotris)形态相似,特别是在幼苗阶段难以识别,在苗种市场上常出现混淆,因此本研究研发了一种分子鉴定技术。通过对mtDNA中COⅠ(cytochrome C oxidase subunitⅠ)基因特异性位点比对和分析,设计并筛选出一对特异性引物(XW1)。特异性引物XW1可在线纹尖塘鳢中扩增获得170 by的单一产物,而在云斑尖塘鳢中无产物。通过PCR扩增产物的有无,可以区分两个物种。并在随机选择的30个样本中得到验证。本研究提供一种可以快速且不需要测序的方法来鉴别云斑尖塘鳢和线纹尖塘鳢。     

人工养殖云斑尖塘鳢的生长特性

研究了人工养殖条件下云斑尖塘鳢（Oxyeleotris marmoratus）的生长特性。结果表明：经过2个月的生长期,云斑尖塘鳢的平均体长从最初的（17．36±0．99）cm增加到（19．05±0．57）cm,体质量从（139．13±12．90）g增加到（205．50±15．78）g,体长增加10％,体质量增加48％。不同的养殖时间除对摄食率（FR）无显著影响外（P〉0．05）,对特定生长率（SGR）、饵料转化效率（FCR）和生长效率（GE）都有显著影响（P〈0．05）。体长生长与时间表现为线性相关,体质量生长与时间表现为指数相关。云斑尖塘鳢体质量与体长之间呈幂函数关系,不同养殖时间下,幂指数b值都接近3,表明云斑尖塘鳢的体长和体质量呈等速生长。     

基于MaxEnt的入侵植物刺轴含羞草的适生分布区预测

【背景】刺轴含羞草是世界危害最严重的100种入侵生物之一,因此明确刺轴含羞草在全球以及中国的潜在分布对有效预防和控制其蔓延具有重要意义。【方法】本研究利用MaxEnt生态位模型对刺轴含羞草在全球以及中国潜在分布区进行预测。【结果】结果表明,刺轴含羞草适生区分布在全球南北纬30度以内的热带和亚热带地区。其中,中南美洲、非洲中部、东南亚以及大洋洲北部为刺轴含羞草中、高度适生区的集中分布区。中国处于刺轴含羞草适生区的边缘。刺轴含羞草在中国的适生区主要分布在云南、海南、广东西南部以及台湾地区。在温室气体A1B排放模式下,到2050年,刺轴含羞草在全球适生区面积与当前相似,但在中国的适生区略有减少。【结论与意义】刺轴含羞草有入侵我国大陆的风险,检疫部门应对刺轴含羞草进行检疫,防止其入侵。     

基于MaxEnt模型的菜豆象全球潜在适生区预测

【目的】菜豆象是重要的检疫性害虫,预测其在全球范围内的潜在适生区可为农业部门开展菜豆象防控工作和检验检疫部门制定检疫策略提供科学依据。【方法】在收集菜豆象已有分布点和全球气象数据的基础上,采用MaxEnt模型对其在全球范围内的潜在适生区进行预测分析。【结果】MaxEnt模型的AUC平均值为0.926,预测结果准确可靠。菜豆象适生区主要分布在欧洲中西部的德国、法国、英国、荷兰、比利时、意大利、波兰、乌克兰、白俄罗斯和罗马尼亚等国家,非洲大陆和马达加斯加岛的中东部地区,北美洲的墨西哥高原和美国中东部地区,南美洲南部地区,大洋洲澳大利亚东部和南部沿海地区、新西兰,亚洲中国的云贵高原、四川盆地、华中和华南地区和台湾岛,缅甸东部地区、泰国和老挝北部地区、尼泊尔和日本大部分地区。高度适生区、中度适生区和低度适生区面积分别占陆地面积的4.95%、6.73%和13.70%。【结论】菜豆象的适生区面积占陆地面积的25.38%,持续扩散和危害的风险大。我国西南、华南地区等地区面临的形势更为严峻。影响菜豆象分布的主要生物气候因素有最冷月份最低温度、年平均温度、年气温变化范围、年降雨量、最干月份降雨量、最热月份最高温度、最暖季度平均温度、温度季节变化方差、昼夜温差月均值等。     

基于MaxEnt模型的入侵植物白花鬼针草的分布预测及适生性分析

【背景】白花鬼针草为农区恶性杂草,原产于美洲,现已广泛分布于世界热带及亚热带地区,但其在全球和中国的适生区域及适生等级还不明确。【方法】利用MaxEnt生态位模型对白花鬼针草在全球以及中国的潜在适生区进行预测。【结果】白花鬼针草在全球的分布更多受到温度因素的影响。白花鬼针草的适生区主要集中在北半球和南半球15°~30°之间的热带和亚热带地区。其中,北美南部、南美中南部、非洲南部、东南亚北部以及大洋洲中南部沿海地区为白花鬼针草中、高度适生区。白花鬼针草在中国的适生区主要位于广东、广西、海南、云南、福建、台湾。到2070年,白花鬼针草在全球的适生区面积与当前相似,但在中国的适生区有所增大。【结论】白花鬼针草在我国有进一步扩张的风险。     

栎方翅网蝽Corythucha arcuata(Say)在中国的潜在适生区预测

【目的】栎方翅网蝽是栎树上的一种重要害虫,自21世纪入侵意大利以来,迅速在欧洲地区暴发成灾。本文旨在探明栎方翅网蝽入侵中国的风险性。【方法】利用MaxEnt生态位模型预测栎方翅网蝽在中国的潜在适生区,分析栎方翅网蝽入侵、定殖和扩散的可能性。【结果】栎方翅网蝽入侵中国并在中国黄河长江中下游平原定殖和扩散的风险性极高,高度适生区包括重庆市、安徽省、湖北省、河南省、浙江省、湖南省、贵州省和四川省。通过分析环境因子重要性表明,最冷季度平均温度是影响栎方翅网蝽适应区的最关键环境变量;年平均温度、等温性和最干季度平均温度是影响栎方翅网蝽适应区分布的主要环境因素。【结论】栎方翅网蝽在我国定殖扩散风险高,建议植物检疫部门加强栎方翅网蝽的监控,并将栎方翅网蝽列入中华人民共和国进境植物检疫性有害生物名录。     

Integrated aquaculture in Chinese lakes and paddy fields

While pond culturing is still the staple of Chinese freshwater fisheries, its extensive development is handicapped by the increasing shortage of land resource for cereal production in face of China’s population growth. Accordingly, people have looked towards the development of aquaculture in lakes (and reservoirs) in the 1970s. This paper reviews the successful integrated measures taken in an experiment for raising fish in Donghu lake (East lake) of Wuhan. By way of (1) stocking the right kinds of fish; (2) producing a large number of sizeable fingerlings; (3) improving fish screens; (4) controlling predatory fish; and (5) applying the ‘driving and concentrating’ bulk harvesting fishing method, fish production of the lake has increased steadily from 180 t in 1971 to 800 t in 1978, and then to 1840 t in 1995, all in an area of 1500 ha, and all without any supplementary feeding. Integrated aquaculture in paddy fields, known to be beneficial to both rice and fish production, has been regaining momentum in recent years. The paper summarizes its underlying principle, its benefits—economical, social and ecological—and the prospect of its development in China.     

An overview of aquaculture in eastern Africa

Egypt, Kenya and Malawi, have the earliest recorded history of fish farming in eastern Africa, dating back to the beginning of the century. Between 1940 and 1960 aquaculture started in Rwanda, Uganda Zambia, Zimbabwe and Tanzania in that order. Overall, Egypt is the leader in aquaculture development in the region with an estimated annual production of 24 000t (1982), followed by Zambia, 1680t (1967), then Kenya, 1085t (1985). The main aquaculture systems in practice are: monoculture, polyculture, using tilapia as the main species, mono or polyculture of tilapia with animal husbandry and rice-cum-fish culture. Aquaculture research and training are carried out in Universities, research institutions and Government Fisheries Training colleges. The major common constraints to aquaculture development are biological, infrastructural and economic.     

Within-family marker-assisted selection for aquaculture species

A within-family marker-assisted selection scheme was designed for typical aquaculture breeding schemes, where most traits are recorded on sibs of the candidates. Here, sibs of candidates were tested for the trait and genotyped to establish genetic marker effects on the trait. BLUP breeding values were calculated, including information of the markers (MAS) or not (NONMAS). These breeding values were identical for all family members in the NONMAS schemes, but differed between family members in the MAS schemes, making within-family selection possible. MAS had up to twice the total genetic gain of the corresponding NONMAS scheme. MAS was somewhat less effective when heritability increased from 0.06 to 0.12 or when the frequency of the positive allele was < 0.5. The relative efficiency of MAS was higher for schemes with more candidates, because of larger fullsib family sizes. MAS was also more efficient when male:female mating ratio changed from 1:1 to 1:5 or when the QTL explained more of the total genetic variation. Four instead of two markers linked to the QTL increased genetic gain somewhat. There was no significant difference in polygenic genetic gain between MAS and NONMAS for most schemes. The rates of inbreeding were lower for MAS than NON-MAS schemes, because fewer full-sibs were selected by MAS.     

植物在水产养殖废水处理中的研究进展

植物在生长繁殖过程中能吸收利用、富集、吸附和固定水产养殖水体中的有机物、无机物和重金属,降低养殖水体中的TP、TN、TSS、COD和BOD。同时,植物在水体中可通过其发达的通气组织和根系传输氧气,为微生物和其他生物的代谢活动提供适宜的条件。选择合适的植物构建人工湿地,通过人工湿地中植物、微生物和基质的物理作用、化学作用和生物作用处理水产养殖废水,可建立循环的水产养殖模式。将植物应用于水产养殖废水的处理,是实现可持续发展的生态型水产养殖的基础。本文综述了近年来藻类和高等植物在水产养殖废水处理中的研究进展。     

Biotechnology and fish culture

Biotechnology can currently be considered of importance in aquaculture. The increase in the production of aquatic organisms over the last two decades through the use of biotechnology indicates that in a few generations biotechnology may overtake conventional techniques, at least for the commercially more valuable species. In the last few years, genetics has contributed greatly to fish culture through the application of the more recent techniques developed in biotechnology and in genetic engineering. At present, the most commonly used methods in fish biotechnology are chromosome manipulation and hormonal treatments, which can be used to produce triploid, tetraploid, haploid, gynogenetic and androgenetic fish. These result in the production of individuals and lineages of sterile, monosex or highly endogamic fish. The use of such strategies in fish culture has as a practical objective the control of precocious sexual maturation in certain species; other uses are the production of larger specimens by control of the reproductive process and the attainment of monosex lines containing only those individuals of greater commercial value. The use of new technologies, such as those involved in gene transfer in many species, can result in modified individuals of great interest to aquaculturists and play important roles in specific programmes of fish production in the near future.     

Continent-specific Intake Fractions and Characterization Factors for Toxic Emissions: Does it make a Difference?

Goal and Scope The goal of this study is to explore the potentials and limitations of using LCA as the basis for setting ecolabelling criteria in developing countries. The practicality of using LCA for this purpose, as required by ISO 14020, has been criticised as lacking in transparency and scientific rigour. Furthermore, ecolabelling is not widespread in developing countries. The application of LCA has therefore been illustrated by using the specific case of shrimp aquaculture in Thailand, as a basis for ecolabelling criteria for a typical product intended for export from a developing country. Method For the LCA case study, the functional unit is the standard consumer-package size, containing 1.8 kg of frozen shrimp produced by conventional intensive aquaculture in Thailand, subject to an appropriate environmental management system. The impact assessment method used in this study is CML 2 Baseline 2000. Results According to the results from the LCA study, farming appears to be the key life cycle stage generating the most significant environmental impacts: abiotic depletion and global warming, which arise mainly from the use of energy; and eutrophication caused by wastewater discharged from the shrimp ponds. It is possible to cover these impacts by quantitative ecolabelling criteria. Other important impacts could not be quantified by the LCA: depletion of wild shrimp broodstock, impacts of trawling on marine biodiversity and the choice of suitable farm sites. These impacts, which are also related to the farming stage, must be covered by 'hurdle criteria'. Conclusions and recommendations. For the present case, LCA provides a basis for quantifying a number of important ecolabelling criteria related to the use of abiotic resources and to emissions. Other important issues, connected with the use of biotic natural resources and land, are not quantifiable by current LCA methodology, but were also revealed and clarified by using an LCA framework for the analysis. Thus, focussing the assessment on life cycle considerations, as required by ISO 14024, was effective in identifying all key environmental issues. In the light of this case study, main limitations and barriers associated with the application of LCA to setting ecolabelling criteria particularly in developing countries are discussed, including recommendations on how to overcome them.     

Managing marine mollusc diseases in the context of regional and international commerce: policy issues and emerging concerns

Marine mollusc production contributes to food and economic security worldwide and provides valuable ecological services, yet diseases threaten these industries and wild populations. Although the infrastructure for mollusc aquaculture health management is well characterized, its foundations are not without flaws. Use of notifiable pathogen lists can leave blind spots with regard to detection of unlisted and emerging pathogens. Increased reliance on molecular tools has come without similar attention to diagnostic validation, raising questions about assay performance, and has been accompanied by a reduced emphasis on microscopic diagnostic expertise that could weaken pathogen detection capabilities. Persistent questions concerning pathogen biology and ecology promote regulatory paralysis that impedes trade and which could weaken biosecurity by driving commerce to surreptitious channels. Solutions that might be pursued to improve shellfish aquaculture health management include the establishment of more broad-based surveillance programmes, wider training and use of general methods like histopathology to ensure alertness to emerging diseases, an increased focus on assay assessment and validation as fundamental to assay development, investment in basic research, and application of risk analyses to improve regulation. A continual sharpening of diagnostic tools and approaches and deepening of scientific knowledge is necessary to manage diseases and promote sustainable molluscan shellfish industries.     

Survey of antibiotic resistance in an integrated marine aquaculture system under oxolinic acid treatment

The consequences of antibiotic use in aquatic integrated systems, which are based on trophic interactions between different cultured organisms and physical continuity through water, need to be examined. In this study, fish reared in a prototype marine integrated system were given an oxolinic acid treatment, during and after which the level of resistance to this quinolone antibiotic was monitored among vibrio populations from the digestive tracts of treated fish, co-cultured bivalves and sediments that were isolated on thiosulfate-citrate-bile-sucrose. Oxolinic acid minimum inhibitory concentration distributions obtained from replica plating of thiosulfate-citrate-bile-sucrose plates indicated that a selection towards oxolinic acid resistance had occurred in the intestines of fish under treatment. In contrast, and despite oxolinic acid concentrations higher than minimum inhibitory concentrations of susceptible bacteria, no clear evolution of resistance levels was detected either in bivalves or in sediments.     

The potential of freshwater Anostraca for technical applications

Freshwater Anostraca offer a potential for a varietyof technical applications. These include production inaquaculture facilities or harvesting from naturalreserves of cysts or biomass. However, economicalrealism limits the number of viable options to eithersubsidized, or to well-focussed activities aimed atend-products with a high added value.