首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
China''s seas cover nearly 5 million square kilometers extending from the tropical to the temperate climate zones and bordering on 32,000 km of coastline, including islands. Comprehensive systematic study of the marine biodiversity within this region began in the early 1950s with the establishment of the Qingdao Marine Biological Laboratory of the Chinese Academy of Sciences. Since that time scientists have carried out intensive multidisciplinary research on marine life in the China seas and have recorded 22,629 species belonging to 46 phyla. The marine flora and fauna of the China seas are characterized by high biodiversity, including tropical and subtropical elements of the Indo-West Pacific warm-water fauna in the South and East China seas, and temperate elements of North Pacific temperate fauna mainly in the Yellow Sea. The southern South China Sea fauna is characterized by typical tropical elements paralleled with the Philippine-New Guinea-Indonesia Coral triangle typical tropical faunal center.This paper summarizes advances in studies of marine biodiversity in China''s seas and discusses current research mainly on characteristics and changes in marine biodiversity, including the monitoring, assessment, and conservation of endangered species and particularly the strengthening of effective management. Studies of (1) a tidal flat in a semi-enclosed embayment, (2) the impact of global climate change on a cold-water ecosystem, (3) coral reefs of Hainan Island and Xisha-Nansha atolls, (4) mangrove forests of the South China Sea, (5) a threatened seagrass field, and (6) an example of stock enhancement practices of the Chinese shrimp fishery are briefly introduced. Besides the overexploitation of living resources (more than 12.4 million tons yielded in 2007), the major threat to the biodiversity of the China seas is environmental deterioration (pollution, coastal construction), particularly in the brackish waters of estuarine environments, which are characterized by high productivity and represent spawning and nursery areas for several economically important species. In the long term, climate change is also a major threat. Finally, challenges in marine biodiversity studies are briefly discussed along with suggestions to strengthen the field. Since 2004, China has participated in the Census of Marine Life, through which advances in the study of zooplankton and zoobenthos biodiversity were finally summarized.  相似文献   

2.
Greece, as is known, has a coastline of 17 000 km, and over 2000 small and large islands. As expected, the quest of humankind for new sources of matter and energy has been focussed on the sea, with fishery being its primary interest. A number of philosophers and scientists have been involved in the study of this vast ecosystem since ancient times (Aristotle). The political, social and geographical upheavals witnessed in the Greek area, have, however resulted in bringing all these activities to a halt. The first contemporary research work commenced at the end of the 18th century/beginning of the 19th — with marine flora and fauna as its starting point. The first investigations had, of course, been limited to random collections of marine material done in the frame of international exploratory expeditions. Studies became more systematic by the end of the 19th and beginning of the 20th century, with priority being given to the animal kingdom (fish, molluscs, etc.). Investigation of the marine phytobenthos (macrophyceae, phytoplankton) was to follow. The past 40 years research has been more extensive, not limited only to biogeographical evaluations, but also having expanded to physiological and ecological levels. The relevant institutes of Greek universities have all the while watched and contributed to this effort. Today, this kind of research is being supported by the N.M.R.C., the Center of Marine Research, University of Crete, and two research boats which sail the Greek seas. In the ever-changing world, the study of marine flora and fauna has certainly made great progress; however, there are still two big problems to be faced. The first deals with increasing pollution of the seas, the second, with the difficulties in finding and affording adequate financial resources that would enable a more detailed and complete execution of this research work.  相似文献   

3.
Salt and water balance in the Aral Sea are described together with the endemic fauna and flora which were mainly of freshwater origin. During the last thirty years the fauna and flora have undergone dramatic changes due partly to a great increase in salinity as the result of water abstraction from the inflowing rivers and partly as the result of the deliberate and accidental introduction of a wide variety of marine invertebrates and fishes. The increased salinity has eliminated most the species of freshwater origin while many of endemic saline species have been lost as the result of competition with the marine ones. Changes in productivity are described and future prospects for the sea are discussed.  相似文献   

4.
The taxonomic composition of the Middle Ginter Flora of the Ugol’naya Bay area (northeastern Russia) is supplemented with new data based on newly determined and revised materials. The uniqueness of the flora lies in the fact that its age (Middle Cenomanian) is dated to a zone by marine fauna. The floristic assemblage contains 29 species of fossil plants and is dominated by angiosperms and conifers. The refined taxonomic list shows even greater than was earlier supposed similarity of the flora to the Grebenka assemblage from the Krivorechenskaya Formation at the left bank of the Anadyr River, which is the type assemblage of the Grebenka phase of the flora development in northeastern Russia. A new combination is proposed: Ettingshausenia louravetlanica (Herman et Shczepetov) Herman et Moiseeva, comb. nov.  相似文献   

5.
Arctic biogeography: The paradox of the marine benthic fauna and flora   总被引:2,自引:0,他引:2  
The marine benthic fauna and flora that inhabit the shallow arctic sublittoral zone comprise a relatively young marine assemblage characterized by species of either Pacific or Atlantic affinity and notably few endemics. The young character of nearshore arctic communities, as well as their biogeographical composition, is largely a product of the Pleistocene glaciation. However, analysis of more recent collections and comparison between the origins of the benthic fauna and flora present some interesting paradoxes to biogeographers. One enigma is the low frequency of algal species with Pacific affinities in the Arctic, especially in the Chukchi, Beaufort and East Siberian Seas of the Eastern Arctic, which receive direct inputs of northward-flowing Pacific waters. In contrast, animal species with Pacific affinities are found throughout the nearshore regions of the Arctic, reaching their highest frequency in the marginal seas between the New Siberian Islands and the Canadian Archipelago. Organization of published and unpublished data, additional field collections, and the use of cladistics and molecular DNA techniques by systematists are a high priority for future research in reconstructing the evolution of the arctic biotic assemblage.  相似文献   

6.
The French monitoring network, REseau BENThique (REBENT), was launched by the Ministry of the Environment in 2003 following the 1999 Erika oil spill. REBENT aimed to acquire baseline knowledge of coastal benthic habitat distributions with a special focus on biological diversity. This study analyzed data from 38 subtidal rocky reef sites collected by a single diving team of marine biologists along the coast of Brittany from 2004 to 2010. At each site, the depth limits of the algal belts were determined between 0 and ?40 m Chart Datum (CD); the flora and fauna compositions and abundances were sampled at ?3 and ?8 m CD. A total of 364 taxa (156 flora and 208 fauna), belonging to 12 phyla, were identified. The results showed that the depth limit and density of kelp beds increased as water turbidity decreased; moreover, several changes in community structure could be related to water turbidity and temperature. Thus, northern and southern Brittany showed strong differences in diversity and structure of the dominant kelp species (Laminaria hyperborea and Saccorhiza polyschides). The results from this kelp habitat composition survey (dominant kelp species and indicator species) provided important information for local pressure assessments, like increases in turbidity. The data also provided a reference that could be useful for detecting changes in coastal water temperatures due to global warming.  相似文献   

7.
There are many logistic difficulties associated with studying Antarctic marine algae and, as a consequence, the taxonomic information available is far from comprehensive and any generalizations should be regarded with caution. The Antarctic marine benthic flora is characterized by a low species richness. Biogeographical characteristics of the flora are outlined. There is a high degree of endemism, possibly around 35–40%. Other major floristic elements are a group of species with a distribution extending to Tierra del Fuego and subantarctic islands, a group spread through temperate regions of the Southern Hemisphere, and a cosmopolitan group. Ecological observations show that ice has a major effect on the occurrence and distribution of algae, and ecophysiological studies indicate that Antarctic macroalgae possess various adaptations to ice, low temperatures, and strongly seasonal light conditions. Possible trends in the evolution of the Antarctic benthic marine flora, including a reduction in species richness and the origins of biogeographical links with subantarctic and temperate regions of the Southern Hemisphere, are discussed in the context of tectonic and climatic changes over the past 100 million years. A comparison is made with studies on the evolution of shallow-water marine fauna.  相似文献   

8.
The oceanic islands in the Southern Ocean can be considered amongst the remotest shores as, not only are they uninhabited (except for small research stations) and geographically isolated, but they are also enclosed by the oceanographic barrier of the Polar Frontal Zone. We survey island shores in the Scotia Arc mountain chain linking Antarctica to South America, including South Georgia, the South Sandwich archipelago and Adelaide Island off the west coast of the Antarctic Peninsula, and compare our findings to literature reports from two other Scotia Arc island groups (South Orkney and South Shetland archipelagos). The presence of marine pollution (in the form of beached debris) in this region is significant, both as a measure of man's influence on this isolated environment, and due to direct dangers posed to the fauna. This paper reports the results of surveys of beached marine debris at various times in the last decade for each island group. The majority (>70%) of the items recovered were anthropogenic in origin and most of these were synthetic (plastic or polystyrene). Debris densities varied from zero to 0.3 items m-1 but were typically lower than those reported from other regions of the globe. At some localities (South Georgia), marine-debris data showed a close relationship with local fishery activity, whilst at others (South Sandwich Islands) debris appeared to have a more distant origin. Unlike oceanic debris in warm (non-polar) water localities, there was no evidence of any colonisation by biota. Debris accumulation may provide a useful indirect measure of local fishery activity and compliance with CCAMLR regulations, as well as monitoring the state of the oceans and island shores.  相似文献   

9.
Paleotemperatures have been interpreted from the evidence of the diatom flora for an Upper Miocene section of marine diatomaceous sediment near Lompoc, California. The diatom flora has been compared with the distribution of modern diatoms in surface sediments of the North Pacific Ocean to propose a Miocene sea paleotemperature curve for this area of California. Temperatures declined sharply in the Late-Mohnian (Upper Miocene) to a winter minimum of about 10°C. Thereafter, a gradual and fluctuating rise in temperature characterized the latest Miocene (Delmontian); minimum seasonal temperatures approached 17°C by the Early Pliocene.This diatom assemblage paleotemperature curve is supported by other evidence. Independent studies of particular diatom temperature indicator species show the same trends, as do the paleotemperature indications of a fossil fish fauna and the foraminiferal fauna in the section. Furthermore, the curve shows a marked correspondence to paleotemperature curves based on planktonic foraminifers and on radiolarians for the Upper Miocene of southern California, providing an additional tool for paleotemperature reconstruction.  相似文献   

10.
Charophytes and otoliths from theCyrena Beds of the northern Alpine foreland (Hausham and Miesbach synclines, Upper Bavaria) have been studied. A very abundant charophyte flora comprising 12 species, includingStephanochara martinii n. sp., is described and figured. The moderately diverse otolith fauna is documented by tables and SEM-pictures. The studiedCyrena Beds can be dated biostratigraphically as early Chattian and correlated with theChara microcera Zone. The charophytes show strong paleobiogeographic relations to floras in the Mainz Basin/Upper Rhine Graben as well as to western Switzerland and southern France. The otolith fauna is strikingly different from late Chattian faunas of the western Paratethys. The paleoecology indicated by charophytes, otoliths and the accompanying fauna suggests short term variation including freshwater, brackish water and marine influenced environments.  相似文献   

11.
Lin L  Yu H T 《农业工程》2012,32(3):117-122
As the crisis of petroleum-based energy is aggravating and the carbon emission is elevating, the search and exploitation of renewable energy sources such as solar, wind and oceanic powers, are of global interest and underway in some developed countries. In western countries pioneering the oceanic energy utilization, wave is currently an attractive energy source due to the predictability and the ease to be absorbed into power grid. As wave-energy generators (WEGs) and the associated devices interact with the surrounding environment, they would have impacts on the biological components within the ecosystem in the vicinity of WEGs. However, the environmental effects of offshore WEGs on local fauna and flora have yet to be evaluated in a comprehensive way. This article discusses several aspects, including influence of offshore WEGs on marine macrofaunal communities, interactions between offshore WEGs and biofouling organisms, impacts of offshore WEGs on marine birds and of electromagnetic fields (EMFs) on marine animals as well as “artificial reef” effects. If precaution is taken with the planning and construction of offshore WEGs, and environmental monitoring is performed with operation of these devices, marine wave energy can become a desirable alternative to fossil fuels.  相似文献   

12.
Jean-Pierre Suc 《Geobios》1976,9(6):741-767
The present study illustrates clearly how pollen analysis may be applied to stratigraphy from a botanical point of view. Within a chronologically reliable frame (Middle Pliocene for the marine deposits on the basis of Foraminifera record; two subzones for continental deposits on the basis of Mammals record: Hautimagne for Terrats fauna, Sète for Serrat-d'en-Vacquer fauna), palynology provides a good stratigraphical boundary: the extinction of the Taxodiaceae. In a remblayage area, it is established that a continental level is not necessarily younger than a marine one unless they are superposed. Many profiles are replaced according to the «progradation of the pliocene gulf of Roussillon. The boundary between marine and continental deposits cuts through the chronological line of the Taxodiaceae extinction. The flora investigated (93 taxa) is the first known for the Pliocene of this area. The extinction of the Taxodiaceae in southern France has a climatic cause: the setting in of a mediterranean rhythm (dry summers). This extinction is much older than the one which took place in Italy (Tiberian boundary) and in the Netherlands (Reuverian-Pretiglian boundary).  相似文献   

13.
The vertical distribution of common species of macroalgae and fauna on rocky shores extending through the length of the estuary is described. In the west, the shores are fully marine and exposed to Atlantic waves. In an eastward direction, greater shelter and an increasing tidal range occur along a gradient of salinity and turbidity. The flora and fauna change along this gradient. No single biological feature signals a transition from the Bristol Channel to the Severn Estuary but four arbitrary regions are recognized: a 'marine' section eastwards to Swansea, a 'transitional' section between Swansea and Cardiff, an 'estuarine' section up to Newnham, and the tidal river Severn.  相似文献   

14.
Numerous threats impact coral reefs and conservation actions are urgently needed. Fast production of marine habitat maps promotes the use of habitat-only conservation plans, where a given percentage of the area of each habitat is set as conservation objectives. However, marine reserves can impact access to fishing grounds and generate opportunity costs for fishers that need to be minimized. In New Caledonia (Southwest Pacific), we used fine-scale fishery catch maps to define nineteen opportunity costs layers (expressed as biomass catch loss) considering i) total catches, ii) target fish families, iii) local marine tenure, and iv) gear type. The expected lower impacts on fishery catch when using the different cost constraints were ranked according to effectiveness in decreasing the costs generated by the habitat-only scenarios. The exercise was done for two habitat maps with different thematic richness. In most cases, habitat conservation objectives remained achievable, but effectiveness varied widely between scenarios and between habitat maps. The results provide practical guidelines for coral reef conservation and management. Habitat-only scenarios can be used to initiate conservation projects with stakeholders but the costs induced by such scenarios can be lowered by up to 50–60% when detailed exhaustive fishery data are used. When using partial data, the gain would be only in the 15–25% range. The best compromises are achieved when using local data.  相似文献   

15.
The fish biodiversity of Lake Nokoué, a lagoon in Bénin, was monitored for one year from August 2000 to July 2001 by means of samples from the artisanal fishery collected once a month at three stations. A total of 5 933 fish weighing 95 322g (mean individual weight 16.0g) belonging to 51 species, 47 genera and 34 families were sampled. An abundance of juveniles was observed, confirming the importance of the lake as nursery grounds, rich in exploitable habitats like other tropical estuaries and lagoons. The fish fauna comprised three main components: i) an estuarine component (strict, freshwater and marine origins) which is the basis of the lagoon fauna community and which is stable in space and time; ii) a marine component containing fishes which appeared in the lagoon during the dry season where the salinity remains high (>20‰) and iii) a freshwater component with fishes coming into the lagoon from the river during the flood period. The magnitude of the spatial and seasonal fluctuations of the last two components varies depending on the area: marine (Zogbo), freshwater (Vêki) or intermediate (Ganvié). The global species richness and the relative abundances of fish vary between stations and from month to month. November, with 20 species on average, and January, with 6 species on average, are significantly different as regards species richness.  相似文献   

16.
Fossil plants are scarce in the Earliest Triassic marine deposits of western Guizhou and eastern Yunnan. Only Annularia shirakii, Lobatannularia sp., Paracalamites stenocostatus, Gigantopteris sp., Pecopteris sp. were reported from the base of the Kayitou Formation dated as Early Induan by marine fauna. Recently, we discovered numerous representatives of the genus Annalepis in the same Lowermost Triassic beds: A. latiloba, Abrevicystis, Aangusta, Annalepis spp. occur associated with a basal Triassic marine fauna. This discovery fills the biostratigraphic gap between the Late Permian “Gigantonoclea guizhouensis-Ullmannia cf. bronnii-Annularia pingloensis” and the late Lower Triassic “Neuropteridium–Albertia–Voltzia” assemblages reported from South China. It represents an important datum dealing with the very beginning of a new terrestrial flora installation after the Permian flora disappearance following the Permian–Triassic boundary mass extinction. This “starting point” of a new vegetal cover in South China is to be taken into account in reconstructing through space and time the settlement process of the Mesozoic floristic provinces.  相似文献   

17.

Background  

Insects that feed on plants contribute greatly to the generation of biodiversity. Hypotheses explaining rate increases in phytophagous insect diversification and mechanisms driving speciation in such specialists remain vexing despite considerable attention. The proliferation of plant-feeding insects and their hosts are expected to broadly parallel one another where climate change over geological timescales imposes consequences for the diversification of flora and fauna via habitat modification. This work uses a phylogenetic approach to investigate the premise that the aridification of Australia, and subsequent expansion and modification of arid-adapted host flora, has implications for the diversification of insects that specialise on them.  相似文献   

18.
19.
Certain palaeoecological criteria in the reconstruction of the Palaeogene palaeobiogeography of the Indian subcontinent are discussed. The Early Palaeogene is characterised by marine oscillations, a prolific invertebrate fauna, extensive coal facies development and outpouring of basaltic lava flows, the last being a feature connected with the movement of the Indian Plate and coinciding with a Himalayan orogenic impulse. The Middle Eocene transgression marks the transition of marine sedimentation to fluvial conditions in northern India with the presence of a fairly diverse mammalian fauna in northwestern Pakistan and northern India. During the Late Oligocene, mammals clearly ancestral to the much more prolific Siwalik fauna were present in western Pakistan, northeastern India and southcentral Burma.The flora consists of mainly tropical to subtropical families with the addition of some temperate elements in Assam in the latter half of the Eocene and Oligocene. Invertebrates indicate a close affinity between the western and eastern sectors and suggest that the sea was continuous in the north at least up to the Palaeocene. With the emergence of land in the northeastern part of the subcontinent, the fauna of Assam acquired distinct Indo-Pacific elements similar to those of Burma and the Indonesian Arc. Later, the sea was divided into two gulfs which gradually shrank towards the end of the Palaeogene and disappeared by the Middle Miocene.  相似文献   

20.
Islands can be sites of dynamic evolutionary radiations, and the Hawaiian Islands have certainly given us a bounty of insights into the processes and mechanisms of diversification. Adaptive radiations in silverswords and honeycreepers have inspired a generation of biologists with evidence of rapid diversification that resulted in exceptional levels of ecological and morphological diversity. In this issue of Molecular Ecology, tiny waterfall‐climbing gobies make a case for their place among Hawaiian evolutionary elite. Moody et al. ( 2015 ) present an analysis of gene flow and local adaptation in six goby populations on Kaua'i and Hawai'i measured in three consecutive years to try to disentangle the relative role of local adaptation and gene flow in shaping diversity within Sicyopterus stimpsoni. Their study shows that strong patterns of local selection result in streams with gobies adapted to local conditions in spite of high rates of gene flow between stream populations and no evidence for significant genetic population structure. These results help us understand how local adaptation and gene flow are balanced in gobies, but these fishes also offer themselves as a model that illustrates why adaptive diversification in Hawai'i's marine fauna is so different from the terrestrial fauna.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号