中国外来海洋生物入侵的现状、危害及其防治对策

全球经济一体化逐步发展,国际间人流和物流日益增加,生物入侵问题已成为人们共同关心的问题。我国对陆地生物的入侵已展开逐步深入的研究,但对海洋生物入侵却关注很少,而且都停留在一般性资料的分析和推测上,实地调查和试验数据更少,对其危害的程度和如何防治也没有基础数据。针对此类问题,就我国外来海洋生物入侵现状作一概述,希望引起社会各界重视,积极开展这方面的研究,预防重大海洋生物入侵灾害的发生,并为我国外来海洋生物入侵的广泛深入的防治研究提供技术支撑。     

斑纹小贻贝的营养成分分析与评价

外来物种是一把“双刃剑”,对本土生态环境和社会经济产生重要影响,准确评估外来物种的营养价值是发挥其经济效益的重要环节。作为近年来侵入我国东南沿海的外来物种,斑纹小贻贝（Mytella strigata）一方面威胁着本地种翡翠股贻贝的生存,另一方面在海南、福建等地区已作为海产品被售卖和食用。在此背景下,本研究依据国家食品安全检测相关标准,对斑纹小贻贝软体部常规营养指标进行测定,分析与评估斑纹小贻贝的营养价值。结果显示：斑纹小贻贝软体部水分、灰分、粗蛋白和粗脂肪的含量（湿重）分别占83.20%、2.00%、12.09%和0.60%;共检测出16种氨基酸,占粗蛋白总量的84.53%,其中7种为必需氨基酸,占氨基酸总量的35.23%,必需氨基酸指数EAAI评分为76.24分,第一限制性氨基酸是半胱氨酸+蛋氨酸;检测出18种脂肪酸,包括7种饱和脂肪酸,占43.71%,4种单不饱和脂肪酸,占11.05%,7种多不饱和脂肪酸,占45.27%,DHA和EPA分别为脂肪酸总量的19.85%和13.32%;矿质元素种类丰富,钙、铁、锌、锰等微量元素含量高。研究表明,斑纹小贻贝软体部氨基酸比例符合FAO/W...     

A critical analysis of objective criteria and methods in conflict and land-use mapping

In geography, as in other types of social science, the discussion of objectivity has been a long-standing issue. This article is mainly about concept definition and analysis. It discusses the problem of objectivity in science and planning, and shows how it functions in planning activities, with a focus on conflict-mapping and land-use mapping in particular. All specific planning applications face certain meta-theoretical considerations of how to deal with different types of knowledge and how to use them in planning. Different professionals carry out planning activities, and geographers are important contributors in this field. It is argued that criteria and methods that often are taken to be objective hide value systems and conflicts. There needs to be a broader understanding that what are called facts change through time, and thus their validity cannot be taken to be absolute. There are different ways of 'knowing' the world and constructing answers to problems. Often criteria and methods are used to present definitive solutions, when different propositions should have been matters for discussion and negotiation among the different interest groups during the process.     

Invasion and spreading of Cabomba caroliniana revealed by RAPD markers

Applying randomly amplified polymorphic DNA (RAPD), the genetic variation ofCabomba caroliniana Gray (cabomba or fanwort), a new alien plant in China, was analyzed in this paper. Total 143 bands, including 47 polymorphic bands, were amplified from 23 primers in 20 samples. The sampling distance was large, but its genetic diversity was low. The main results were that: (1) Cabomba, which grew and dispersed mainly in fragment, was an abundant and dominant species in freshwater, and its main dispersal mechanism was vegetative reproduction (2) Cabomba was originally introduced into China as an aquarium submerged plant. Somehow, those discarded cabomba became invasive species in the areas of Hangzhou, Shanghai, and Meicheng, and other places. (3) Although the level of genetic diversity in cabomba was low, their rapid dispersion and propagation could seriously harm to local aquatic community. Therefore, specific measure should be used to control cabomba from uncontrolled spreading and damage to local vegetation communities. Supported by National Natural Science Foundation of China (No. 39970145) and Major State Basic Research Development Program of China (No. G2000046803).     

上海崇明东滩互花米草生态控制与鸟类栖息地优化工程

崇明东滩鸟类国家级自然保护区是迁徙水鸟的重要栖息地。近10余年来,保护区面临着互花米草Spartina alterniflora的入侵、鸟类栖息地退化、土著植被萎缩等生态问题。通过实施崇明东滩互花米草控制和鸟类栖息地优化工程,新建了25 km长的围堤从空间上阻断了互花米草扩张途径,并形成了"围、割、淹、晒、种、调"的生态治理方针。工程在鸟类栖息地优化区内营造了鸻鹬类主栖息区、苇塘区、雁鸭类主栖息区、鹤类主栖息区和科研监测管理区,并总结出各生境类型的地形要素与群落要素配置特点与管理要求。工程还支持了潮间带滩涂土著植物海三棱藨草Scirpus mariqueter的种群重建与复壮任务。最后,通过规范工程的后续管理和成效监测,为保护区的后期建设规划和科学管理提供了实践经验。     

Adriatic ‘opisthobranchs’ (Gastropoda,Heterobranchia): shedding light on biodiversity issues

We herein review the Adriatic opisthobranch fauna, provide an updated checklist of 223 species and assess their distribution at regional and country levels. New Adriatic records are provided for 67 opisthobranch taxa, adding three new records for the Italian coastline, five new records for Albania, eight for Croatia and 15 for Montenegro. The presence of Hermaea bifida (Montagu, 1815), Hermaea variopicta (Costa A., 1869) and Facelina annulicornis (Chamisso & Eysenhardt, 1821) is reported for the first time from anywhere in the Adriatic Sea. Including the new findings, our inventory includes 28 species from Albania, 163 from Croatia, 178 from the Italian coastline of the Adriatic, 41 from Montenegro and 74 from Slovenia. No records were available from Bosnia and Hercegovina. Ninety species (40.4%) are widespread, and were recorded from all three main divisions (Northern, Western and Eastern Adriatic), whilst 79 species (35.4%) were reported from only one of them. At sub‐division levels, the Albanian inventory is the most dissimilar to the other country/regional lists, presumably because of the lack of targeted field surveys. The highest similarity is observed amongst the Western Adriatic, Croatia and the Italian Ionian coastline. Seven alien, one possible alien and three cryptogenic opisthobranchs were reliably recorded from the Adriatic Sea. The first Mediterranean records of five species were in the Adriatic Sea, of which four species have not been found elsewhere in the Mediterranean. Shipping and aquaculture are the probable pathways for most of the alien species. A steady rate of one to two alien introductions per decade since the 1970s was evident. The Northern Adriatic coasts are the most affected by alien invasions, probably due to repeated local introductions along with shellfish transfers (oysters, mussels, Manila clams), and heavy maritime transport.     

Distribution,population size and conservation of the Cape gannet Morus capensis

The Cape gannet is endemic to the southern African coast where it currently breeds at six islands: Mercury, Ichaboe and Possession off South West Africa and Bird (Lambert's Bay), Malgas and Bird (Algoa Bay) off South Africa. Previously, breeding also occurred at Hollams Bird, Halifax and Seal (False Bay) Islands. Equivocal records for Marcus, Dassen and Dyer Islands are not accepted. Off South West Africa, gannets were breeding at Hollams Bird, Mercury and Ichaboe Islands at least as early as 1828, but they only occupied Halifax and Possession Islands sometime between that date and c. 1885, possibly as a result of displacement of gannets from Ichaboe Island during exploitation of accumulated guano deposits in the early 1840s. Gannets bred at Hollams Bird Island until at least 1938, but had ceased breeding at Halifax Island by 1928. Off South Africa the earliest records of breeding are 1648, 1687, 1755 and 1912 for Malgas, Seal (False Bay), Bird (Port Elizabeth) and Bird (Lambert's Bay) Islands respectively. Gannets have not been reported at Seal Island since the late 17th century. On the west coast of Africa the Cape gannet is a regular nonbreeding winter visitor as far north as 4°20′N 6°00′E, but west of 6°E it is rare. On the east coast of Africa it is a common winter visitor as far north as Delagoa Bay, but farther north it is rare. Within its normal range the Cape gannet seldom occurs farther off shore than 100 km; it hardly ever moves inland. Aerial censuses of Cape gannets at breeding islands in 1967, 1969, 1978, 1980 and 1981 are compared with an aerial census conducted in 1956 and other published estimates of abundance. Between 1956 and 1980 the estimated number of breeding pairs at all colonies decreased from c. 150 000 to c. 80 000 and numbers decreased at all three extant gannetries off South West Africa. These decreases are attributed to a greatly diminished food resource following the collapse of the South West African pilchard stock after the late 1960s. The number of gannets decreased at Bird (Lambert's Bay) and Malgas Islands between 1956 and the late 1960s but subsequently increased, trends that are related to performances of the Western Cape pilchard and anchovy resources respectively. At Bird Island (Algoa Bay) gannets were up to 3,5 times more abundant in the late 1970s than in 1956. Other marine resources located east of Cape Point have shown similar large increases in recent years. Rates of increase of gannets at islands off South Africa during the 1970s would have required an unrealistically high survival for the first year had other population parameters remained constant. It is possible that birds emigrated from the South West African Islands. Few gannets have been reported oiled, and conservation of the species seems to be mainly affected by greatly reduced prey availability and injudicious guano harvesting. Human exploitation of juvenile gannets off the West African coast is difficult to assess.