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1.
海洋浮游动物多样性及其分布对全球变暖的响应   总被引:1,自引:0,他引:1  
针对日益加剧的全球增温和生物多样性丧失等现象,结合浮游动物在海洋生态系统中的重要性,从世界各大海域的浮游甲壳类、水母类及毛颚类等群落对海洋表层温度升高及海流变化的响应等方面进行了综述,以期为进一步深入开展相关研究提供参考。  相似文献   

2.
The purpose of this study was to examine the distribution, abundance and characteristics of plastic particles in plankton samples collected routinely in Northeast Pacific ecosystems, and to contribute to the development of ideas for future research into the occurrence and impact of small plastic debris in marine pelagic ecosystems. Plastic debris particles were assessed from zooplankton samples collected as part of the National Oceanic and Atmospheric Administration's (NOAA) ongoing ecosystem surveys during two research cruises in the Southeast Bering Sea in the spring and fall of 2006 and four research cruises off the U.S. west coast (primarily off southern California) in spring, summer and fall of 2006, and in January of 2007. Nets with 0.505 mm mesh were used to collect surface samples during all cruises, and sub-surface samples during the four cruises off the west coast. The 595 plankton samples processed indicate that plastic particles are widely distributed in surface waters. The proportion of surface samples from each cruise that contained particles of plastic ranged from 8.75 to 84.0%, whereas particles were recorded in sub-surface samples from only one cruise (in 28.2% of the January 2007 samples). Spatial and temporal variability was apparent in the abundance and distribution of the plastic particles and mean standardized quantities varied among cruises with ranges of 0.004-0.19 particles/m3, and 0.014-0.209 mg dry mass/m3. Off southern California, quantities for the winter cruise were significantly higher, and for the spring cruise significantly lower than for the summer and fall surveys (surface data). Differences between surface particle concentrations and mass for the Bering Sea and California coast surveys were significant for pair-wise comparisons of the spring but not the fall cruises. The particles were assigned to three plastic product types: product fragments, fishing net and line fibers, and industrial pellets; and five size categories: <1 mm, 1-2.5 mm, >2.5-5 mm, >5-10 mm, and >10 mm. Product fragments accounted for the majority of the particles, and most were less than 2.5 mm in size. The ubiquity of such particles in the survey areas and predominance of sizes <2.5 mm implies persistence in these pelagic ecosystems as a result of continuous breakdown from larger plastic debris fragments, and widespread distribution by ocean currents. Detailed investigations of the trophic ecology of individual zooplankton species, and their encounter rates with various size ranges of plastic particles in the marine pelagic environment, are required in order to understand the potential for ingestion of such debris particles by these organisms. Ongoing plankton sampling programs by marine research institutes in large marine ecosystems are good potential sources of data for continued assessment of the abundance, distribution and potential impact of small plastic debris in productive coastal pelagic zones.  相似文献   

3.
The zooplankton community of the subarctic Pacific is relatively simple, and contains a similar set of major species in all deep water areas of the subarctic Pacific. Their role in the food web varies considerably between coastal and offshore locations. In the oceanic gyres, microzooplankton and other mesozooplankton taxa replace phytoplankton as the primary food source for the dominant mesozooplankton species. Micronekton and larger zooplankton probably replace pelagic fish as major direct predators. Productivity and upper ocean biomass concentrations are intensely seasonal, in part because of seasonality of the physical environment and food supply, but also because of life history patterns involving seasonal vertical migrations (400–2000 m range) and winter dormancy. During the spring–summer season of upper ocean growth, small scale horizontal and vertical patchiness is intense. This can create local zones of high prey availability for predators such as planktivorous fish, birds, and marine mammals. On average, the cores of the subarctic gyres have lower biomass and productivity than the margins of the gyres. There is also some evidence that the Western Gyre is more productive than the Alaska Gyre, but more research is needed to confirm whether this east–west gradient is permanent. There is increasing evidence that the pattern of zooplankton productivity is changing over time, probably in response to interdecadal ocean climate variability. These changes include 2–3 fold shifts in total biomass, 30–60 day shifts in seasonal timing, and 10–25% changes in average body length.  相似文献   

4.
海洋浮游植物和浮游动物是海洋生态系统中的重要组成部分,支撑了整个海洋生态系统的正常运转.因此,海洋浮游植、动物的生态学研究有利于我们全面认识和了解一个海洋生态系统的状况.印太交汇区作为全球最大的海洋生物多样性中心,是国际上生物多样性研究的热点区域,但该区域对浮游生物生态学方面的研究较少,不利于我们深入认识该区域生物多样...  相似文献   

5.
Designing a representative network of high seas marine protected areas (MPAs) requires an acceptable scheme to classify the benthic (as well as the pelagic) bioregions of the oceans. Given the lack of sufficient biological information to accomplish this task, we used a multivariate statistical method with 6 biophysical variables (depth, seabed slope, sediment thickness, primary production, bottom water dissolved oxygen and bottom temperature) to objectively classify the ocean floor into 53,713 separate polygons comprising 11 different categories, that we have termed “seascapes”. A cross-check of the seascape classification was carried out by comparing the seascapes with existing maps of seafloor geomorphology and seabed sediment type and by GIS analysis of the number of separate polygons, polygon area and perimeter/area ratio. We conclude that seascapes, derived using a multivariate statistical approach, are biophysically meaningful subdivisions of the ocean floor and can be expected to contain different biological associations, in as much as different geomorphological units do the same. Less than 20% of some seascapes occur in the high seas while other seascapes are largely confined to the high seas, indicating specific types of environment whose protection and conservation will require international cooperation. Our study illustrates how the identification of potential sites for high seas marine protected areas can be accomplished by a simple GIS analysis of seafloor geomorphic and seascape classification maps. Using this approach, maps of seascape and geomorphic heterogeneity were generated in which heterogeneity hotspots identify themselves as MPA candidates. The use of computer-aided mapping tools removes subjectivity in the MPA design process and provides greater confidence to stakeholders that an unbiased result has been achieved.  相似文献   

6.
This study uses a comparative approach to examine responses of marine ecosystems to climatic regime shifts. The three seas surrounding the Korean peninsula, the Japan/East Sea, the East China Sea and the Yellow Sea represent three contiguous but distinct ecosystems. Sampling has been carried out by the National Fisheries Research and Development Institute of South Korea since 1965, using the same methods in all three seas. Sampling was generally synoptic. Amplitude time series of 1st EOF modes for temperature, salinity, zooplankton biomass and concentrations of four major zooplankton taxa were used to determine whether the three marine ecosystems respond in a similar manner to climate variations. Temporal patterns of the variables were strongly similar among the three seas at decadal time scales, but very weakly similar at interannual scales. All three seas responded to a climatic regime shift that occurred in 1989. Temperature, zooplankton biomass and copepod concentrations increased in the late 1980s or early 1990s in all three seas. Concentrations of amphipods, chaetognaths and euphausiids also increased in the Japan/East Sea and the East China Sea, but not the Yellow Sea. The Yellow Sea ecosystem differs strongly from the other two seas, and water exchange between the Yellow Sea and the East China Sea is much weaker than that between the East China Sea and Japan/East Sea. Spatial patterns of zooplankton determined by the EOF analysis were closely related to currents and fronts in each of the three seas.  相似文献   

7.
Though ubiquitous in the global oceans, double diffusive mixing has been largely ignored or poorly represented in the models of turbulent mixing in the ocean and in 3-D ocean models, until recently. Salt fingers occur in the interior of many marginal seas and ocean basins, the Tyrrhenian Sea and the subtropical Atlantic being two examples. Diffusive convection type of double diffusion occurs in the upper layers of many sub-polar seas and polar oceans due to cold melt water from sea ice. Consequently, it is important to be able to properly parameterize double diffusive mixing in basin scale and global ocean models, so that the water mass structure in the interior of the ocean can be properly simulated. This note describes a model for double diffusive mixing in the presence of background shear, based on Mellor–Yamada type second moment closure, more specifically Kantha, 2003, Kantha and Clayson, 2004 second moment closure models of resulting turbulence, following Canuto et al. (2008a) but employing a different strategy for modeling the pertinent terms in the second moment equations. The resulting model is suitable for inclusion in ocean general circulation models.  相似文献   

8.
Carnivorous zooplankton in the Benguela system have tended to be ignored by all but early taxonomists and a handful of recent researchers. An attempt is made here to address the importance of carnivores in this system but, because the database is poor, it was necessary to apply material from outside the region. The taxa covered include ctenophores, cnidarians (Scyphozoa and Hydrozoa, including Siphonophora), chaetognaths and hyperiid amphipods as well as such minor groups as pelagic gastropods and decapods. Most groups of carnivores within the Benguela are represented by only one or two "common" species. These tend to be epiplanktonic and generally concentrated inshore of the shelf-break, where their distributions are influenced by changes in local hydrography. Their densities frequently exceed those of herbivores. The dominant carnivores share a number of attributes: wide-ranging diets, high assimilation and growth efficiencies and mostly a Type I functional response to food concentration. They fall into two categories. The first is the gelatinous species, which have short lifespans and exhibit rapid growth and often massive reproductive response to high concentrations of food. They are patchily distributed and some appear to have behavioural traits that enable them to stay within localized patches of prey on which they may be dependent because of high metabolic costs. In the second category are crustacean predators and chaetognaths which have slower response times to the food environment but may have longer lifespans, lower daily maintenance needs and an ability to store lipids. They are less dependent on high densities of food organisms and can survive throughout winter, when gelatinous predators are rare. The effect of predation on abundance of copepods is estimated on the basis of both published and unpublished data. Should swarms of predators coincide with a critical gateway of zooplankton or larvae, then there may be total depletion. This applies especially to the nearshore zone of the West Coast and to semi-enclosed bays. The role of carnivorous zooplankton in the diets of commercially important fish species is stressed, but their importance in the regeneration of nutrients may be insignificant.  相似文献   

9.
The 2004 Pew Ocean Commission report suggests a need to improve public literacy about oceans. The authors of the report assume that enhancing public awareness and knowledge of oceans will lead to increased public support for ocean restoration efforts. Following this line of reasoning, our study investigates current levels of public knowledge and informedness concerning oceans, and also explores the correlates of knowledge holding. Using data gathered from a national random sample of 1233 citizens in Summer/Fall 2003, two hypotheses—trans-situational and situation-specific—are examined as explanations of public knowledge levels concerning ocean policy issues. The trans-situational hypothesis evaluates socioeconomic status (SES) as an explanation for levels of knowledge. The situation-specific hypothesis evaluates personal experiences and contexts that might overcome SES characteristics. We also examine the effect of information source use on knowledge holding. Findings suggest that both trans-situational and situation-specific hypotheses are useful in explaining knowledge levels. We also find that information sources, such as newspapers and the internet, are likely to improve citizen knowledge on ocean issues, while television and radio have a negative effect.  相似文献   

10.
上层海洋浮游生物地理分布   总被引:2,自引:1,他引:1  
确定海洋浮游生物的分布区域是海洋浮游生态学研究的首要任务之一,本文总结了上层海洋(0-200 m)浮游生物地理分布的研究历史、已有的认知及全球变化的影响.对浮游生物地理分布的研究可以分为19世纪末期至20世纪70年代、20世纪80年代至2000年,以及2000年以后三个时期.根据分布区资料的时间长短,浮游生物分布区分为...  相似文献   

11.
印度洋浮游生态系统的特点及其对全球变暖的响应   总被引:1,自引:0,他引:1  
与太平洋和大西洋相比,印度洋有独特的季风和洋流系统和由此驱动的浮游生物分布及生产规律.在全球变暖的背景下,印度洋的变暖趋势比太平洋和大西洋更为显著,是研究变暖对海洋浮游生态系统影响的热点海区之一.文章结合国内外文献,评述印度洋浮游生态系统的现状、特点及对全球变暖的响应,包括印度洋的浮游生物地理分布、南北印度洋浮游生态系...  相似文献   

12.
1997年6~8月于山东省海阳市黄海集团公司养虾场,用5个实验围隔研究了对虾池不同粒级浮游生物的呼吸率和初级生产率.结果表明:(1)小型、微型及超微型浮游生物的呼吸率平均分别为0.07,0.38及0.31mg/(dm3·d),占各粒级浮游生物总呼吸率的9%,50%及41%.小型、微型及超微型浮游植物的生产率平均分别为0.04,1.26及0.15mg/(dm3·d),占相应粒级浮游植物总生产率的3%,87%及10%.各粒级浮游生物呼吸率占相应粒级浮游植物生产率的比例为:小型浮游生物175%;微型浮游生物30%;超微型浮游生物207%.(2)小型浮游动物、超微型浮游动物(含细菌)的呼吸率显著高于相应粒级浮游植物呼吸率,微型浮游植物的呼吸率明显高于微型浮游动物呼吸率.不同粒级浮游植物呼吸率的大小顺序为微型、超微型、小型,不同粒级浮游动物呼吸率顺序为超微型(含细菌)、微型、小型.  相似文献   

13.
The global importance and context of methane escape from the seabed   总被引:8,自引:1,他引:8  
Seabed fluid flow includes volcanic and hydrothermal fluid emissions from ocean spreading centres, island arcs, and intra-plate volcanism, and groundwater flows in some coastal areas. Of direct concern to this paper is the escape of methane from the seabed. Escaping methane may be of microbial, thermogenic or abiogenic origin. Escapes occur in all seas and oceans, in coastal waters, on continental shelves, slopes and rises, the deep oceans, and deep ocean trenches. These represent a variety of geological contexts on passive continental margins, at convergent plate margins (accretionary wedges) and transform plate boundaries. Seepage is clearly widespread, and it contributes methane to the biosphere, the hydrosphere and the atmosphere, thus making up an important part of the global carbon cycle.  相似文献   

14.
After a short introduction to the physical setting and the history of biological research the pelagic ecosystem of the Kara Sea is described. Main emphasis is on regional aspects of the plankton communities and their seasonal dynamics using mostly data collected between 1996 and 2001. In the zooplankton, for which most data were available, four regional aggregations were separated: (1) the rivers and estuaries of the Southern Kara Sea, (2) the south-western and (3) the central Kara Sea, and (4) the northern troughs and slope. The phytoplankton communities had a similar distribution. To provide components for detailed carbon budgets the regional dynamics of bacterial, phytoplankton and zooplankton biomass and production are described and carbon requirements of bacteria and zooplankton are estimated. For completeness a short literature review on higher trophic levels is included. Finally, recent observations of the pelago-benthic coupling are considered. Estimates of the carbon requirements from the plankton and benthos reveal a large underestimation of primary production, which to date, together with seasonal aspects, shows the largest gap in our knowledge.  相似文献   

15.
The modern Sea of Okhotsk and the high-latitude glacial ocean share similar radiolarian faunas suggesting they also share environmental similarities. This sea favors deep- (>200 m) over shallow-living species as evidenced by collections of sediment traps set at 258 and 1061 m in the central part of the Sea. Of the twelve dominant polycystine radiolarian species, four live above and eight below 258 m. The shallow-living species’ productivity maxima coincide with spring and fall phytoplankton blooms while deep-living species’ annual production, nearly twice that of the shallow-living species, is concentrated in fall. Previous workers have shown that summer plankton tows collect higher concentrations of polycystine Radiolaria below than above 200 m and that Radiolaria, fish and zooplankton have unusual concentration maxima between 200 and 500 m. The paucity of Radiolaria and other consumers above 200 m coincides with an upper (0–150 m) cold (−1.5°C to 1.5°C), low salinity layer while higher concentrations below 200 m occur within warmer saltier water. This unusual biological structure must produce a lower ratio of shallow (<200 m) to deep carbon remineralization than elsewhere in the world ocean.Deep-living radiolarian species, similar to those of the modern Sea of Okhotsk, dominate glacial high-latitude deep-sea sediments. If the hydrographic and biological structures that produced these glacial faunas were like those of the modern Sea of Okhotsk, then glacial high-latitude oceans would have differed from today's in at least two respects. Surface waters were less saline and more stable enhancing the spread of winter sea ice. This stability, combined with a deepening of nutrient regeneration, reduced surface water nutrients contributing to a reduction of atmospheric carbon dioxide.  相似文献   

16.
We examined plankton responses to climate variance by using high temporal resolution data from 1988 to 2007 in the Western English Channel. Climate variability modified both the magnitude and length of the seasonal signal of sea surface temperature, as well as the timing and depth of the thermocline. These changes permeated the pelagic system yielding conspicuous modifications in the phenology of autotroph communities and zooplankton. The climate variance envelope, thus far little considered in climate-plankton studies, is closely coupled with the non-stationary dynamics of plankton, and sheds light on impending ecological shifts and plankton structural changes. Our study calls for the integration of the non-stationary relationship between climate and plankton in prognostic models on the productivity of marine ecosystems.  相似文献   

17.
海洋生态系统累积影响评估是科学认知该系统对外界扰动响应与反馈规律的生态学方法.为了探索和揭示其中的内在规律,本文以我国部分近陆海域为研究范围,选取海洋渔业、海洋航运、陆源及近海、气候变化4种类型下的16个生态压力因子,通过空间量化和标准化,在1 km×1 km空间格栅尺度下,针对研究范围内9种海洋生境类型,进行了累积暴...  相似文献   

18.
本文系统梳理了IPCC 《气候变化中的海洋和冰冻圈特别报告》(SROCC)的主要结论,并对主要观点进行了解读。报告主要关注全球变暖背景下高山、极地、海洋和沿海地区现在和未来的变化及其对人类和生态系统的影响,以及实现气候适应发展路径的方案。在全球变暖背景下,冰冻圈大面积萎缩,冰川冰盖质量损失,积雪减少,北极海冰范围和厚度减小,多年冻土升温,全球海洋持续增温,1993年以来,海洋变暖和吸热速度增加了一倍以上。同时,海洋表面酸化加剧,海洋含氧量减少。全球平均海平面呈加速上升趋势,2006—2015年全球海平面上升速率为3.6 mm/yr,是1901—1990年的2.5倍,但存在区域差异。高山、极地和海洋的生态系统的物种组成、分布和服务功能均发生变化,并对人类社会产生了显著负面影响。极端海洋气候事件发生频率增多,强度加大。1982年以来,全球范围内海洋热浪的发生频率增加了一倍,且范围更广,持续时间更长。海平面持续上升加剧了洪涝、海水入侵、海岸侵蚀等海岸带灾害,并影响沿海生态系统。海洋及冰冻圈的变化及其影响在未来一定时期仍将持续,应对这些影响而面临的挑战,应加强基于生态系统的适应和可再生能源管理,强化海岸带地区的海平面上升综合应对,打造积极有效、可持续和具有韧性的气候变化应对方案。  相似文献   

19.
海南清澜港水母暴发期间浮游生物生态特征研究   总被引:2,自引:0,他引:2  
自2010年12月-2011年5月,调查研究了海南清澜港海域的浮游生物群落特征,重点跟踪监测了2011年5月黄斑海蜇(Rhopilema hispidum)暴发期间海水营养盐水平及浮游生物群落结构变化。通过样品分析,共鉴定出浮游植物111种(变种和变型),细胞密度范围为(2.25×104)-(8.19×108)cells/L,浮游动物36种,丰度范围为19.39-25798.74ind/L,其中浮游动物以桡足类为优势种群,浮游植物以硅藻为主要优势种。在水母暴发期间浮游植物以热带骨条藻(Skeletonema tropicum)为主,浮游动物以桡足类为主。清澜港养殖区为水母水螅体提供生长发育的环境和水母暴发前期浮游植物大量增殖,为浮游动物提供充足的食物,在一定程度上促进了水母的暴发。  相似文献   

20.
2009-08对乐清湾进行了生物调查。共鉴定浮游动物66种,浮游幼虫15类,分为半咸水河口类群、近海暖温带类群、近海暖水类群和大洋广布类群,其中近海暖水类群占主导地位。Ⅰ型网主要优势种有针刺拟哲水蚤、汤氏长足水蚤、太平洋纺锤水蚤、刺尾纺锤水蚤等;Ⅱ型网主要优势种有针刺拟哲水蚤、强额拟哲水蚤、太平洋纺锤水蚤、刺尾纺锤水蚤、短角长腹剑水蚤、简长腹剑水蚤、小长腹剑水蚤等。浮游动物优势种分布有明显差别,太平洋纺锤水蚤分布仅限于湾顶海区,小长腹剑水蚤密集区也在此区域,其它优势种则分布于乐清湾中部和湾口海区。浮游动物平均生物量为125.05mg/m3,平均丰度为234.00个/m3,数量分布呈现出从湾顶向湾口逐渐降低的趋势。  相似文献   

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