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1.
Zhao Huanting 《中国地理科学(英文版)》1997,8(2):144-151
Landscapes of the Nansha Islands may be divided into five types: tropical marine organism-breeding landscape of reef knoll
like Zengmu Shoal, Wan’an Bank and so on; tropical marine organism-breeding landscape of atoll including all emerged reefs
and most submerged reefs; tropical evergreen arbor-bush forest and phosphorous lime soil landscape of limesand Islets like
Taiping Islet, Nanwei islet and so on; tropical shallow sea marine organism-breeding landscape of southern continental shelf;
tropical oceanic and deep-sea marine organism landscape in middle and north parts of the Nansha Islands area. These five landscape
types may be also summed up as two categories, one is tropical sea landscape including those in shallow and deep sea, the
other is tropical coral reef landscape including those of reef knoll, atoll and limesand islet. This paper outlines the evolutional
model of landscapes of the Nansha Islands. The distribution and evolution of landscape types are related with palaeogeography
and modern environmental conditions. The former shallow sea of the Nansha islands was coastal zone in the Late Pleistocene
epoch. Deep sea is evolved from shallow sea due to long and slow subsidence of crust. Modern coral reefs develop on old reef
top of the Late pleistocene epoch or on baserock of continental shelf in the Holocene due to the rise of sea level in postglacial.
Limesand islet is in the peak of developmental stage. 相似文献
2.
根据 2003年南沙群岛西南陆架区春秋两次调查资料,分析南沙群岛西南陆架区深水金线鱼的资源现状。结果表明,深水金线鱼分布广泛,平均渔获率为 9. 9kg·h-1,渔获率有明显的季节变动,秋季高于春季,密集分布于 71~80m水深。其群体组成也有季节差异,春季的平均体长、平均体重大于秋季,优势体长组春季为 131 ~140mm,秋季为 121~130mm,渔获优势年龄组为Ⅰ ~Ⅱ龄鱼。目前其资源密度及资源量分别为 129. 41kg·km-2和9 .484 21t,资源量是原始资源量的 46%,该资源已明显衰退。同时文中还讨论了合理利用该资源的措施。 相似文献
3.
Observation data from a cruise in the Nansha Islands, in May to June 1990, December, 1993, September to October 1994, and July, 1999, respectively, were used to develop the method presented here to indicate the existing strength of the dissolved oxygen maximum in the vertical distribution of Nansha Islands waters. Its seasonal variation and regional distribution are discussed in this paper. Analysis results showed that the distribution of the strength of dissolved oxygen maximum (DOmax-DOsur) was closely related to the upper layer circulation and the bioactivity of Nansha Islands seawater. 相似文献
4.
报道了中国南沙群岛的双壳纲贝类141种,分隶于5亚纲8目36科77属.从种类的组成中,帘蛤科有18种,蚶科15种,扇贝科11种,鸟蛤科10种,锉蛤科8种,贻贝科、海菊蛤科和樱蛤科各7种,砗磲科6种,其他各科的种类均在5种以内.按种的性质而论,大多数属于和珊瑚礁有密切联系的热带种或亚热带种,区系性质为印度-西太平洋区的印尼-马来亚区. 相似文献
5.
The Andaman and Nicobar Islands are one of the Union Territories of India, located in the eastern part of the Bay of Bengal. In 2010 summer, the increment in sea surface water temperature (up to 34℃) resulted in the bleaching of about 74% to 77% of corals in the South Andaman. During this event, coral species such as Acropora cerealis, A. humilis, Montipora sp., Favia pallida, Diploastrea sp., Goniopora sp. Fungia concinna, Gardineroseries sp., Porites sp., Favites abdita and Lobophyllia robusta were severely affected. This study is to assess the recovery status of the reef ecosystem by estimating the percentage of Live Coral cover, Bleached coral cover, Dead coral with algae, Rubble, Sandy flat, Algal assemblage and other associated organisms. The sedimentation rate (mg cm-2 d-1) and coral coverage (%) were assessed during this study period. The average sedimentation rate was ranged between 0.27 and 0.89 mg cm-2 d-1 . The observed post bleaching recovery of coral cover was 21.1% at Port Blair Bay and 13.29% at Havelock Island. The mortality rate of coral cover due to this bleaching was estimated as 2.05% at Port Blair Bay and 9.82% at Havelock Island. Once the sea water temperature resumed back to the normal condition, most of the corals were found recovered. 相似文献
6.
unomicrroNTherearereportedstudisoninorganicsulfurcomPoundsinrnarinesedtritS(Song,l99(),Stefan,l994),butfeWonorganicsulfurcomPounds.Itwasshownthatthroughoilspthe,mnoffandatmosphdriproasses,manyanthropogedcorganicsulfurcomP0undsrnaybethenspotalintothemarineenvirorstWheretheycanbeeventuallydePositalalongwithnatamlorganicstilfUrcomPoundsinseddritSraateSetal.,l979).ResearchesonorganicstilfurcomPoundsinrnarinesedirnentSareofpotentialenvirornnentalchdricalshoilicanceforhaherunderstandingofthege… 相似文献
7.
2010年7月利用灯光罩网和延绳钓对南沙北部海域进行了初步的渔业资源调查,报道了该海域的鸢乌贼(Symplectoteuthis oualaniensis)和金枪鱼的渔获与分布状况。灯光罩网平均CPUE 63.90 kg/网,主要渔获物为鸢乌贼,占总产量的67.57%,平均胴长122 mm,质量89.6 g;延绳钓平均CPUE为18.19 kg/百钩,其中大目金枪鱼(Thunnus obesus)3.24 kg/百钩、短鳍斜齿鲨(Scoliodon Palasorrah)10.46 kg/百钩,渔获尾数较多的为帆蜥鱼(Alepisaurus ferox)和黑魟(Dasyatis atratus),分别占总数的39.13%和26.09%。提出南沙金枪鱼捕捞采用延绳钓与灯光罩网联合方式的建议。 相似文献
8.
In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands(44.55%±11.10% cover) followed by tabular forms in the Doga Islands(ranging between 18%±6.47% and 18.30%±9.47% cover). Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area(58.89%±15.11% cover) followed by the Jeddah coast(24.76%±14.04% cover). The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah(10.70%±8.21%) and Al-Wajh(9.81%±6.69%). The live coral cover(including both Scleractinian and non-Scleractinian corals) of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acroporid corals was greater in the southern region than in the northern and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah(Northern region) and the second one comprised the middle and southern regions(Jeddah to Farassan Islands), and one outlier Rabigh. 相似文献
9.
《青岛海洋大学学报(英文版)》2014,(2):243-248
In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands (44.55%±11.10% cover) fol-lowed by tabular forms in the Doga Islands (ranging between 18%±6.47% and 18.30%±9.47% cover). Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area (58.89%±15.11% cover) followed by the Jeddah coast (24.76%±14.04% cover). The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah (10.70%±8.21%) and A1-Wajh (9.81%±6.69%). The live coral cover (including both Scleractinian and non-Scleractinian corals) of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acro- porid corals was greater in the southern region than in the northem and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah (Northem region) and the second one comprised the middle and southem regions (Jeddah to Farassan Islands), and one outlier Rabigh. 相似文献
10.
在与外交部建立密切协调沟通机制、以我国外交部的政策方针为引导的基础上,遵循"以人为本、预防为主、综合效益、统一领导"的原则,可设立"南沙涉外渔业纠纷危机应对指挥部",下设"南沙涉外渔业纠纷危机应对事务委员办公室"和"南沙涉外渔业纠纷危机应对专家顾问团"两个职责分明的常规机构,以此构建南沙涉外渔业纠纷应急组织体系,预防并降低南沙海域内突发涉外渔业纠纷可能对南沙捕捞业造成的负面影响。 相似文献
11.
The altitudinal pattern of vegetation is usually identified by field surveys,however,these can only provide discrete data on a local mountain.Few studies identifying and analyzing the altitudinal vegetation pattern on a regional scale are available.This study selected central Inner Mongolia as the study area,presented a method for extracting vegetation patterns in altitudinal and horizontal directions.The data included a vegetation map at a 1∶1 000 000 scale and a digital elevation model at a 1∶250 000 scale.The three-dimensional vegetation pattern indicated the distribution probability for each vegetation type and the transition zones between different vegetation landscapes.From low to high elevations,there were five vegetation types in the southern mountain flanks,including the montane steppe,broad-leaved forest,coniferous mixed forest,montane dwarf-scrub and sub-alpine shrub-meadow.Correspondingly,only four vegetation types were found in the northern flanks,except for the montane steppe.This study could provide a general model for understanding the complexity and diversity of mountain environment and landscape. 相似文献
12.
Heavy metal content in coral reef sediments from Red Sea of Yemen and its significance on marine environment
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In order to determine and assess the concentrations of trace elements in coral reefs sediments from Red Sea of Yemen, sediment samples were collected, treated and analyzed for cadmium, chromium, cobalt, copper, manganese, nickel, iead, iron, zinc and vanadium by the atomic absorption spectrometric analysis. The result is that cadmium, cobalt and lead concentrations were high and other elements are low or the same as natural background. It is concluded that the high cadmium, cobalt and lead levels in coral reefs sediments will have negative effects on marine life of the sites, so further researches are needed to characterize the sources fate, biogeochemical processes and impacts of these trace elements on coral reefs and marine of the region. 相似文献
13.
Characteristics of nitrogen forms in the surface sediments of southwestern Nansha Trough,South China Sea 总被引:5,自引:0,他引:5
The area of the southwestern Nansha Trough is one of the most productive areas of the southern South China Sea.It is a typical semi-deep sea area of transition from shoal to abyssal zone.To understand distributions and roles of nitrogen forms involved in biogeochemical cycling in this area,contents of nitrogen in four extractable forms:nitrogen in ion exchangeable form(IEF-N),nitrogen in weak acid extractable form(WAEF-N),nitrogen in strong alkali extractable form(SAEF-N) and nitrogen in strong oxidation extractable form(SOEF-N),as well as in total nitrogen content(TN) in surface sediments were determined from samples collected from the cruise in April-May 1999.The study area was divided into three regions(A,B and C) in terms of clay sediment(<4 μm) content at <40%,40%-60% and >60%,respectively.Generally,region C was the richest in the nitrogen of all forms and region A the poorest,indicating that the finer the grain size is,the richer the contents of various nitrogen are.The burial efficiency of total nitrogen in surface sediments was 28.79%,indicating that more than 70% of nitrogen had been released and participated in biogeochemical recycling through sediment-water interface. 相似文献
14.
In order to determine and assess the concentrations of trace elements in coral reefs sediments from Red Sea of Yemen, sediment samples were collected, treated and analyzed for cadmium, chromium, cobalt, copper, manganese, nickel, lead, iron, zinc and vanadium by the atomic absorption spectrometric analysis. The result is that cadmium, cobalt and lead concentrations were high and other elements are low or the same as natural background. It is concluded that the high cadmium, cobalt and lead levels in coral reefs sediments will have negative effects on marine life of the sites, so further researches are needed to characterize the sources fate, biogeochemical processes and impacts of these trace elements on coral reefs and marine of the region. 相似文献
15.
徐闻珊瑚礁礁栖无脊椎动物分布 总被引:6,自引:1,他引:6
采用均匀定点潜水观察和采集标本调查表明,徐闻珊瑚自然保护区除分布有40多种珊瑚 外,尚分布有隶属于软体动物门、节肢动物门、棘皮动物门、环节动物门、腔肠动物门和海绵动物门 的55科115种礁栖无脊椎动物,分布的方式主要有穴居、附着和固着等3种方式,部分种类在礁丛 中索饵而隐蔽或躲避在礁缝隙中。 相似文献
16.
邢福武,李泽贤,叶华谷,陈炳辉,吴德邻ASTUDYONTHEFLORISTICPLANTGEOGRAPHYOFXISHAISLANDS,SOUTHCHINA¥XingFuwu;LiZexian;YeHuagu;ChenBinghui;WuDelin(... 相似文献
17.
Wavenumber and depth properties of temperature finestructure in the region around the Ryukyu Islands
INTRODUCTIONTheoceanicfinestructureintheEastChinaSea (ECS)Kuroshioregionhadbeenstudiedbyvariousresearchers.Fangetal.(1 988)studiedthefeaturesofthefinestructureinthesouthernshelfareaandtheKuroshioareaintheECSbyusingCTDdata .Baoetal.(1 996)analyzedsomefeaturesofthermohalinefinestructureandrevealeditsrelationwiththewatermassesandcurrentssysteminthenorthernECS .ButoceanicfinestructureintheeasternregionoftheKuroshiohassel dombeenstudied .Inthispaper,basedon 4 2CTDprofilesgatheredinsum… 相似文献
18.
ESR dating of aragonitic and calcitic corals , eolianite , calcrete , and corallineae from coral reefs in the South China Sea was applied to study of Quaternary reef geology . The ESR ages of calcitic corals correlated with the biostratigraphy , lithostratigraphy and geochemistry of Well Xi-Chen-1 and the oxygen-isotope stratigraphy of deep sea sediments, were reliable and up to 1.26 Ma. The selection of signals for dating and other related problems are discussed . 相似文献
19.
Dinophysis caudata generated lipophilic shellfish toxins in bivalves from the Nanji Islands,East China Sea 总被引:1,自引:0,他引:1
A 12-month program of monitoring potentially toxic microalgae(that produce lipophilic shellfi sh toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identifi ed, and D. caudat a was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38×10 2 cells/L in surface water and 1.25×10 2 cells/L in bottom water(10 m deep). The temporal distribution of D. caudata was associated with the occurrence of LSTs in bivalve samples, which mostly occurred at the same time as D. caudata blooms, between April and July 2006. All of the cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 μg okadaic acid(OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit(20 μg OA eq./100 g meat). Ten out of fi fteen wild samples(66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 μg OA eq./100 g meat(more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 μg OA eq./100 g meat, and relatively high toxicities(80 to 160 μg OA eq./100 g meat) were found in bivalves until the end of July. 相似文献