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1.
夏季南黄海浮游动物分布及其影响因素分析   总被引：4，自引：1，他引：3  
王晓  王宗灵  蒲新明  刘萍 《海洋学报》2013,35(5):147-155
基于2006年7-8月在南黄海西部 (32°~37°N,124°E以西) 进行的137个站位的浮游动物大面调查,研究了浮游动物的种类组成、丰度、生物量、优势种及生态环境指示种的分布及影响因素。结果显示,浮游动物种类组成较以往多,中华哲水蚤对浮游动物丰度贡献最高,超过50%,生物量也明显高于以往,本研究胶质性浮游动物生物量超过非胶质性浮游动物。优势种组成差别不大,中华哲水蚤存在2个丰度高值区,一个位于叶绿素a浓度较低的黄海冷水团内,一个位于海区南部;强壮滨箭虫出现频率最高,高丰度区与中华哲水蚤不同,主要位于山东半岛南岸至海州湾外侧;细足法鲹主要分布在34°N以北的冷水团范围内,在盐度低于31的海区几乎绝迹;太平洋磷虾主要分布在33°~35°N的深水区。暖水种精致真刺水蚤和肥胖软箭虫在海区南部较多,与北向的长江冲淡水和台湾暖流有关,其分布北限受到南向的苏北沿岸流和黄海冷水团的影响,这两种浮游动物在南黄海的分布可以反映上述海流的相互作用。  相似文献   

2.
Samples were collected with a plankton net in the four seasonal cruises during 2006-2007 to study the seasonal variability of the zooplankton community in the southwest part of Huanghai Sea Cold Water Mass (HSCWM, Yellow Sea Cold Water Mass). The spatial and temporal variations of zooplankton species composition, biomass, abundance and biodiversity were examined. A total of 122 zooplankton species and 30 pelagic larvae were identified in the four cruises. Calanus sinicus and Aidanosagitta crassa were the most dominant species, and Themisto gaudichaudi and Euphausia pacifica were widely distributed in the HSCWM area. The spatial patterns of non-gelatinous zooplankton (removing the high water content groups) were similar to those of the total zooplankton biomass in autumn, but different significantly in the other three seasons. The seasonal means of zooplankton biomass in spring and summer were much higher than that in autumn and winter. The total zooplankton abundance averaged 283.5 ind./m~3 in spring (highest), 192.5 ind./m~3 in summer, 165.5 ind./m~3 in autumn and 65.9 ind./m~3 in winter (lowest), and the non-gelatinous groups contributed the most total abundance. Correlation analysis suggests that the non-gelatinous zooplankton biomass and abundance had a significant positive correlation in the whole year, but the relationship was insignificant between the total zooplankton biomass and abundance in spring and summer. The diversity index H of zooplankton community averaged 1.88 in this study, which was somewhat higher than historical results. Relatively low diversity in summer was related to the high dominance of Calanus sinicus, probably due to the strongest effect of the HSCWM in this season.  相似文献   

3.
The most plausible scenarios for seasonal to interannual variabilities and their possible causes are investigated for the Tsushima Current system passing through the Japan Sea. The study is based on the north and south two-box model across the polar front in an idealized upper ocean of the Japan Sea. The boxes are connected by lateral diffusive heat transport and cooled by atmospheric forcing at the annual mean state. The south box, i.e. the Tsushima Current region, only interacts with the outside warmer box in the East China Sea and has an eastward thermal-driven current originating in the outside box. The magnitude of this current depends on the strength of the thermal gradient between the north and south boxes; the inflow of warm waters can therefore be maintained by net heat loss through the sea-surface. I call such a thermal-driven inflow process a "Cooling-Induced Current" system in the present study. Under periodical heat forcing, the perturbation response of the model to water temperature fields and inflow transport were examined. It is shown that the lateral diffusion time across the polar front (over a period of 10 years) is crucial to the interannual modeled response. An analysis of the seasonal heat budget suggests that the heat transported into the Japan Sea from the East China Sea in summer is stored mainly within the Tsushima Current region and contributes to heat loss by the sea-surface cooling in winter.  相似文献   

4.
Seasonal and interannual change in mesozooplankton community structure in the offshore Tsushima Current area of the Japan/East Sea was studied in relation to climatic events and temporal variability of the upper water column environment from 1991 to 1999. We observed a clear seasonal succession in zooplankton community structure from a cold-water copepod-dominated community in winter and spring to a gelatinous, carnivorous and warm-water copepod-dominated community in summer and autumn. The mean abundance (inds. m−3) of the spring community was 3–4-fold higher than that of the other season. The spring community structure varied considerably between years: the community characterized by the summer–autumn type zooplankton assemblage appeared in 1991–1993 and 1998, while the community characterized by high abundance of cold-water copepods appeared in the mid 1990s. Time series profiles of water density and nutrients showed the thickness of the surface warm Tsushima Current and the cold subsurface water increased and decreased, respectively, limiting nutrient supply to the surface water in 1992 and 1998. These results suggest that a thick, warm surface layer might reduce the reproductive success and survival ratio of the cold-water copepods both directly and indirectly, by hindering their upward migration to the surface where food is available, and by limiting phytoplankton growth due to nutrient depletion, respectively. A Monsoon Index (MOI) showed weaker winter wind stress in 1992 and 1998, which might have attenuated formation of the cold subsurface layer in the northern Japan/East Sea and been responsible for surface warming of the study area. Since 1992 and 1998 were El Niño years, this study revealed that ENSO related climatic variability on an interannual time scale considerably influenced the lower trophic level ecosystem in the Japan/East Sea.  相似文献   

5.
ＤｉｓｔｒｉｂｕｔｉｏｎｏｆｂｉｏｍａｓｓｏｆｚｏｏｐｌａｎｋｔｏｎｉｎｔｈｅＫｕｒｏｓｈｉｏａｒｅａｏｆｔｈｅＥａｓｔＣｈｉｎａＳｅａ￥ＭｅｎｇＦａｎ;ＣｈｅｎＳｈｉｑｕｎａｎｄＷｕＢａｏｌｉｎｇ（ＦｉｒｓｔｉｎｓｔｉｔｕｔｅＯｆＯｃｅａｎｏｇｒａ...  相似文献   

6.
We investigated species composition and spatial distribution of the euphausiid community in the Yellow Sea and identified the relationship with environmental factors (temperature, salinity, chlorophyll a, nitrate, phosphate, and silicate) using bimonthly data from June, 1997 to April, 1998. The environment varied during the sampling period. In warm seasons, thermocline was well developed rendering lower temperature and higher salinity and nutrient concentrations in the bottom layer. During cold seasons the water column was well mixed and no such vertical stratification was noted. Horizontal distribution of temperature, however, differed slightly between near-coast and offshore areas because of the shallow depth of the Yellow Sea, and between southern and northern areas because of the intrusion of water masses such as Yellow Sea Warm Current and Changjiang River Diluted Water. Four euphausiid species were identified:Euphausia pacifica, E. sanzoi, Pseudeuphausia sp. andStylocheron affine. E. sanzoi andS. affine were collected, just one juvenile each, from the southern area in June and December, respectively.Pseudeuphausia sp. were collected in the eastern area all the year round except June.E. pacifica occurred at the whole study area and were the predominant species, representing at least 97.6% of the euphausiid abundance. Further, the distribution pattern of the species was varied in regards to developmental stages (adult, furcilia, calyptopis, egg). From spring to fall,E. pacifica adults were abundant in the central area where the Yellow Sea Bottom Cold Water prevailed. Furcilia and calyptopis extended their distribution into nearly all the study area during the same period. From late fall to winter, adults were found at the near-coastal area with similar pattern for furcilia and calyptopis. The distribution pattern ofE. pacifica was consistent regarding temperature, salinity, and three nutrients during the sampling period, whereas chlorophyll a showed a different pattern according to the developmental stages. The nutrients should indirectly affect via chlorophyll a and phytoplankton concentration. With respect to these results, we presented a scenario about how the environmental factors along with the water current affect the distribution ofE. pacifica in the Yellow Sea.  相似文献   

7.
By using a rectangular basin of uniform depth with inflow and outflow openings, the circulation in the Japan Sea is investigated numerically. Heat flux through the sea surface is determined from the annual mean atmospheric conditions for the Japan Sea, but no wind stress is considered.In the transient state, the warm water supplied through an inflow opening travels cyclonically along the coast as a density-driven boundary current in a rotating system. In the quasi-steady state, the warm water flows northward as a western boundary current which corresponds to the East Korean Warm Current and gradually separates from the coast as it flows northward. No strong boundary current corresponding to the nearshore branch of the Tsushima Current exists.Under annual mean atmospheric conditions, formation of the deep water characteristic of the Japan Sea and of the thermal front corresponding to the Polar Front do not take place.  相似文献   

8.
Long-term studies in the Sea of Okhotsk (1986–2012) demonstrated that hyperiids account for a small portion of zooplankton, making up only from 1.0 to 5.3% by weight. The minimum hyperiid biomass was observed in the coastal zone. The hyperiid biomass in the open water shelf community increased from spring to autumn. In the Sea of Okhotsk, hyperiids are represented by ten species, among which the most abundant in the northern regions (mainly in Shelikhov Gulf) is Themisto libellula, while the most abundant in other regions is T. pacifica. The distribution of T. pacifica in different seasons showed that the maximum biomass was concentrated in the deep-water zone. The range of T. libellula in the Sea of Okhotsk is mostly limited to the Shelikhov Gulf, but in certain years its habitation area can expand. In warm years with low ice coverage, the maximum expansion of T. libellula to the west in the shelf zone of the northern part of the Sea of Okhotsk was observed. Since variability of salinity and temperature in the northern part of the Sea of Okhotsk may be fatal for the cryophilic stenohaline T. libellula species, forecasted changes in thermohaline circulation will make it possible to predict the population dynamics of this important species.  相似文献   

9.
南黄海浮游动物主要种类数量分布年间比较   总被引：3，自引：0，他引：3  
陈峻峰  左涛  王秀霞 《海洋学报》2013,35(6):195-203
分析对比1959年、1982年、1998-2000年以及2007-2010年4个不同时期南黄海中部（34.25°~37.45°N,122.00°~124.00°E）浮游动物主要优势种中华哲水蚤（Calanus sinicus）、太平洋磷虾（Euphausia pacifica）和强壮箭虫（Sagitta crassa）数量时空变化及其与温度、盐度和太平洋年代际震荡指数（Pacific Decadal Oscillation,PDO）变动的关系。结果显示,温度可能对中华哲水蚤和太平洋磷虾数量分布影响较大;强壮箭虫则受盐度影响较大。PDO暖位相时期中华哲水蚤和太平洋磷虾数量显著低于冷位相时期,强壮箭虫则相反。中华哲水蚤和太平洋磷虾丰度与提前3个月PDO值呈显著正相关,强壮箭虫丰度仅与当月PDO值呈显著正相关。  相似文献   

10.
The diets of breeding seabirds can be a good monitor of marine environmental changes. From 1984 to 2001 we monitored the diets of black-tailed gulls (Larus crassirostris) (“surface foragers”), rhinoceros auklets (Cerorhinca monocerata) (“epipelagic divers”), and Japanese cormorants (Phalacrocorax filamentotus) (“bottom divers”) that breed on Teuri Island at the northern boundary of the Tsushima Warm current in the Sea of Japan/East Sea. Between 1984 and 1987, both the gulls and the auklets foraged on the sardine (Sardinops melanostictus), but after 1992, they switched to the anchovy (Engraulis japonica). This change might reflect the collapse of the sardine stock in the late 1980s. In the 1990s, the year-to-year variations of the percentage of anchovy in the diets of the three seabird species showed similar trends: High in 1994 and 1998–2001; and low in 1992–1993 and 1995–1997. The estimated stock size of the anchovy population in the Tsushima Current area was positively correlated with the percentage of mass of anchovy in the seabirds’ diets. Thus, the short-term annual changes of the total anchovy availability, which might reflect SST or the volume transport of Tsushima Current, possibly affected the seabirds diets on this island.  相似文献   

11.
The invasive ctenophore Mnemiopsis leidyi (Agassiz), which was transported from the Black Sea into the Caspian Sea at the end of the 1990s, has negatively affected the ecosystem of the Caspian Sea. Zooplankton abundance, biomass and species composition were evaluated on the Iranian coast of the Caspian Sea during 2001–2006. A total of 18 merozooplankton (13 species composed of larvae of benthic animals) and holozooplankton (four Copepoda and one Cladocera) species were identified. The total number of zooplankton species found here was 50% less than in a previous investigation performed in the same region in 1996 before the introduction of Mnemiopsis leidyi into the Caspian Sea. Cladocera species seemed to be highly affected by the invasion of Mnemiopsis leidyi; only one species, Podon polyphemoides, remained in the study area, whereas 24 Cladocera species were found in the study carried out in 1996. Whereas among the Copepoda Eurytemora minor, Eurytemora grimmi, Calanipeda aquae dulcis and Acartia tonsa that were abundant before the Mnemiopsis leidyi invasion, only A. tonsa (copepodites and adults) dominated the inshore and offshore waters after the invasion. The maximum in zooplankton abundance (22,088 ± 24,840 ind·m?3) and biomass (64.1 ± 56.8 mg·m?3) were recorded in December 2001 and August 2004, respectively. The annual mean zooplankton abundance during 2001–2006 was in the range of 3361–8940 ind·m?3; this was two‐ to five‐fold less than the zooplankton abundance in 1996. During 2001–2006, the highest abundance and biomass of Mnemiopsis leidyi were observed during summer‐autumn months coincident with warm temperatures and generally when the abundance of other zooplankton organisms was low.  相似文献   

12.
Eddy Field in the Japan Sea Derived from Satellite Altimetric Data   总被引：2，自引：0，他引：2  
The Japan Sea is one of the eddy-rich areas in the world. Many researchers have described the variability of the eddy field and its structure in the Tsushima Warm Current region. On the other hand, since there are few data covering the northern part of the Japan Sea, we are not able to understand the detailed variability of the eddy field there. The variation of the eddy field in the Japan Sea is investigated using the temporal fluctuations of sea surface height measured by altimetric data from TOPEX/POSEIDON and ERS-2. Tidal signals are eliminated from the altimetric data on the basis of the results of Morimoto et al. (2000). Distributions of sea surface dynamic height are produced by using the optimal interpolation method every month. The distributions warm and cold eddies that we obtained coincide well with the observed isotherms at 100 m depth measured by the Japan Sea National Fisheries Research Institute and the sea surface temperature measured by satellite. There are areas with high RMS variability of temporal fluctuation of sea surface dynamic height in the Yamato Basin, the Ulleung Basin, east of North Korea, the eastern part of the Yamato Rise, the Tsushima Strait and west of Hokkaido. The characteristics of eddy propagation in the high RMS variability regions are examined using a lag correlation analysis. Seasonal variations in the number of warm and cold eddies are also examined.  相似文献   

13.
The Korea (Tsushima) Strait is an important seaway through which the warm Tsushima Current flows into the East Sea (Japan Sea). A paleogeographic map constrained by a regional sea-level curve developed on the basis of a number of recent 14C radiocarbon dates suggests that the Korea Strait was not closed during the last glacial period. Rather, it was open as a channel-like seaway linking the western North Pacific and the East Sea. Some fraction of the paleo-Tsushima Current inflow presumably continued at that time through the Korea Strait. The activity of the paleo-Tsushima Current is evidenced by the distribution pattern of river-derived lowstand deposits, consisting of a beach/shoreface complex and lowstand deltaic wedges. Received: 16 April 1999 / Revision accepted: 25 February 2000  相似文献   

14.
A long-term variation in dominant species of chaetognaths in the Tsushima Warm Current was analyzed using samples collected four times a year from 1972 to 2002 by the Maizuru Marine Observatory along the PM transect in the Japan Sea. Of 19 occurring species, 13 subtropical species formed a major portion of the standing stock. Species richness in the study area was similar to that in the East China Sea and the South China Sea. Four species, Sagitta minima, S. nagae, S. enflata, S. elegans dominated in the upper 150 m water column. The most dominant species per season were S. minima in both winter and autumn, S. elegans in spring and S. nagae in summer. Water temperature and salinity ranges of the most frequent occurrence for three dominant species revealed a common tendency in the order of S. nagae > S. minima > S. enflata towards colder temperature and higher salinity. Inter-annual abundance of chaetognath species fluctuated proportionally in response to the warm or cool phases in water temperature. Water temperature was a fundamental factor in regulating distributional occurrence, being more decisive than salinity. Changes of both dominant species and species numbers in relation to the reduced abundance during winter to spring and the subsequent increase during summer to autumn might be caused by specific differences in optimum temperature. Chaetognath species are important as an indicator of water masses and significant for our understanding of changes and evaluations of the Japan Sea ecosystem.  相似文献   

15.
基于声学方法的南黄海浮游动物垂直迁移季节变化研究   总被引：2，自引：1，他引：1  
为研究南黄海浮游动物垂直迁移的季节变化, 分析了2006 年至2007 年4 个季节布放潜标中声学测流仪的观测数据。结果是: 声学测流仪测量的后向散射强度呈现显著的日变化特征, 这是由浮游动物垂直迁移造成的; 在4 个季节中都出现这一凌晨向下、黄昏向上的垂直迁移, 但是垂直迁移发生的时间有季节变化。利用南黄海辐射通量的直接观测数据, 讨论了垂直迁移发生时间与光照的关系,结果表明垂直迁移的季节变化主要受光照的影响。这对于研究浮游动物垂直迁移机制有一定意义。  相似文献   

16.
北黄海獐子岛海域浮游动物群落年际变化   总被引：1，自引：0，他引：1  
本文比较了海洋普查期间（1959年1-12月）和2009-2010年獐子岛海域附近站位的浮游动物的种类组成、优势种、丰度、生物多样性,结果显示,北黄海区域浮游动物群落物种组成未发生较大的变化,在獐子岛海域以及整个北黄海,中华哲水蚤和强壮箭虫的优势种地位没有发生变化,细足法虫戎也一直出现且为冬春季的优势种;太平洋磷虾在2009-2010年獐子岛海域虽然全年均有出现,但是全年均不是优势种,而在1959年的獐子岛海域,作为优势种出现在4月和11月;1959年与2009年相较,腹针胸刺水蚤在春夏季优势种的地位被沃氏纺锤水蚤所取代。2009年浮游动物丰度（131.26 ind/m3）比1959年（78.90 ind/m3）高;浮游动物多样性指数（H'）均在夏秋季高于冬春季节,且年平均多样性指数也有所提高。  相似文献   

17.
The spatial and seasonal variability of primary production in the Japan Sea from 1998 to 2002 was estimated using a satellite primary production model. A size-fractionated primary production model was validated by in situ primary production data measured in the Japan Sea. Estimated primary production and in situ primary production showed a good positive correlation. Estimated primary production showed spatial variability. Annual primary production levels were 170, 161, 191 and 222 gC m−2year−1 at the Russian coast, in the middle of the Japan Basin, the southeastern area and the southwestern area, respectively. It was higher to the south around 40°N than to the north, and higher in the western area than in the eastern one. Peaks of primary production appeared twice, in spring and fall, in the southern area, while a single peak appeared in the northern area. Primary production along the Russian coast was higher than in other areas during summer. The spring bloom contributed 42% to the annual primary production in these four areas. Furthermore, estimated primary production showed an interannual variability that was largest in spring. Primary production in fall also showed interannual variability, especially in the middle of the Japan Basin and the southwestern area. This corresponded mainly to the size of the phytoplankton bloom in each year. Winter convection by wind and the depth of nutrient-rich, cold subsurface water underlying the Tsushima Current may contribute to the nutrient supply to upper layer and interannual variations of primary production in spring.  相似文献   

18.
Northern and southern latitudinal transects were conducted west of Tsugaru Strait to estimate the volume transport in this area. It was found that the Tsushima Warm Current is the northward volume transport across the southern transect and the Northward Current is the northward volume transport across the northern transect. The current in Tsugaru Strait,viz. the Tsugaru Warm Current, is the flow remaining when the Northward Current is subtracted from the Tsushima Warm Current. Both CTD transects covered from near-shore to west of the subarctic front, and observed depths were from the surface to the bottom or to 1000-1500 m depth. Our estimations indicate that large interannual variations of volume transport occur, relative to the seasonal ones, with interannual variations sometimes exceeding seasonal variations in the Tsushima Warm Current and the Northward Current. The Tsugaru Warm Current has near-steady transport. Fluctuations in the Tsushima Warm Current are thus transmitted to the Northward Current. Further, our results revealed seasonal variations in the flow: the baloclinic structure became deeper in April and the current axis tended to shift in a near-shore direction in October. Therefore, previous studies, which had shallow reference levels and lacked nearshore stations, may have underestimated the transport and excessive seasonal variations.  相似文献   

19.
Seasonal variations in the picoplankton community were investigated from June 2002 to March 2004 within the photic zone of Sagami Bay, Japan. The study area was mostly dominated by coastal waters during the warm period (mixed layer water temperature ≥ 18°C). During the cold period (mixed layer water temperature ≤ 18°C), the water mass was characterized by low temperature and high saline waters indicative of the North Pacific Subtropical Mode Water (NPSTMW). Occasionally, a third type of water mass characterized by high temperature and low saline properties was observed, which could be evidence of the intrusion of warm Kuroshio waters. Synechococcus was the dominant picophytoplankton (5−28 × 1011 cells m−2) followed by Prochlorococcus (1−5 × 1011 cells m−2) and picoeukaryotes during the warm period. Heterotrophic bacteria dominated the picoplankton community throughout the year, especially in the warm period. During the Kuroshio Current advection, cyanobacterial abundance was high whereas that of picoeukaryotes and heterotrophic bacteria was low. During the cold period, homogeneously distributed, lower picophytoplankton cell densities were observed. The dominance of Synechococcus in the warm period reflects the importance of high temperature, low salinity and high Photosynthetically Active Radiation (PAR) on its distribution. Cyanobacterial and heterotrophic bacterial abundance showed a positive correlation with temperature. Prochlorococcus and picoeukaryotes showed a positive correlation with nutrients. Picoeukaryotes were the major contributors to the picophytoplankton carbon biomass. The annual picophytoplankton contribution to the photosynthetic biomass was 32 ± 4%. These observations suggest that the environmental conditions, combined with the seasonal variability in the source of the water mass, determines the community structure of picoplankton, which contributes substantially to the phytoplankton biomass and can play a very important role in the food web dynamics of Sagami Bay.  相似文献   

20.
A three-dimensional ecosystem model for the North Sea which includes competition between Pseudocalanus elongatus and the rest of the zooplankton biomass was applied to describe the seasonal cycle of zooplankton in 2003–2004. The paper presents the comparison of simulated stage-resolved abundances with copepod counts at several stations in the German Bight during the GLOBEC-Germany project from February to October 2004. A validation of influential state variables gives confidence that the model is able to calculate reliably the stage development and abundances of P. elongatus as well as the range of bulk zooplankton biomass, and thus the ratio of population biomass to total biomass. In the German Bight, the population is below 20% in spring. The ratio increases up to 50% during summer. The number of generations was estimated from peaks in egg abundance to about 4–8 generations of P. elongatus in the southern North Sea. A mean of four generations per year were estimated in the central North Sea, six to eight generations northwest of the Dogger Bank (tails end) and five generations in the German Bight.  相似文献   

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