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1.
Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou Bay, were analyzed to determine the spatiotemporal variations in temperature, light, nutrients (NO3^--N, NO2^--N, NH4^ -N, SIO3^2--Si, PO4^3--P), phytoplankton, and primary production in Jiaozhou Bay. The results indicated that only silicate correlated well in time and space with, and had important effects on, the characteristics, dynamic cycles and trends of, primary production in Jiaozhou Bay. The authors developed a corresponding dynamic model of primary production and silicate and water temperature. Eq. ( 1 ) of the model shows that the primary production variation is controlled by the nutrient Si and affected by water temperature; that the main factor controlling the primary production is Si; that water temperature affects the composition of the structure of phytoplankton assemblage; that the different populations of the phytoplankton assemblage occupy different ecological niches for C, the apparent ratio of conversion of silicate in seawater into phytoplankton biomas and D, the coefficient of water temperature‘s effect on phytoplankton biomass. The authors researched the silicon source of Jiaozhou Bay, the biogeochemical sediment process of the silicon, the phytoplankton predominant species and the phytoplankton structure. The authors considered silicate a limiting factor of primary production in Jiaozhou Bay, whose decreasing concentration of silicate from terrestrial source is supposedly due to dilution by current and uptake by phytoplankton; quantified the silicate assimilated by phytoplankton, the intrinsic ratio of conversion of silicon into phytoplankton biomass, the proportion of silicate uptaken by phytoplankton and diluted by current; and found that the primary production of the phytoplankton is determined by the quantity of the silicate assimilated by them. The phenomenon of apparently high plant-nutrient concentTations but low phytoplankton biomass in some waters is reasonably explained in this paper.  相似文献   

2.
Preliminary studies on microzooplankton grazing were conducted with dilution method in Jiaozhou Bay from summer 1998 to spring 1999. Four experiments were carried out at St. 5 located at the center of Jiaozhou Bay. Chlorophyll a concentrations were consistently dominated by netphytoplankton (net-, >20μm), except during the autumn 1998 cruise, when they were dominated by nanophytoplankton(nano-, 2–20μm). The contribution of picophytoplankton (pico-, <2μm) to total chlorophyll a concentrations (<200μm) varied considerably between cruises. Instantaneous growth coefficients(u) of phytoplankton varied from 0.098 to 1.947d−1, with mean value of 0.902d−1. Instantaneous coefficients(g) of microzooplankton grazing on phytoplankton ranged from 0.066 to 0.567d−1, mean value of 0.265d−1, which was equivalent to daily lose of 21.9% of the initial standing stock and 58.1% of the daily potential production. Project No KZCX3-SW-214 supported by Chinese Academy of Sciences.  相似文献   

3.
The authors analyzed the data collected in the Ecological Station Jiaozhou Bay from May 1991 to November 1994, including 12 seasonal investigations, to determine the characteristics, dynamic cycles and variation trends of the silicate in the bay. The results indicated that the rivers around Jiaozhou Bay provided abundant supply of silicate to the bay. The silicate concentration there depended on river flow variation. The horizontal variation of silicate concentration on the transect showed that the silicate concentration decreased with distance from shorelines. The vertical variation of it showed that silicate sank and deposited on the sea bottom by phytoplankton uptake and death, and zooplankton excretion. In this way, silicon would endlessly be transferred from terrestrial sources to the sea bottom. The silicon took up by phytoplankton and by other biogeochemical processes led to insufficient silicon supply for phytoplankton growth. In this paper, a 2D dynamic model of river flow versus silicate concentration was established by which silicate concentrations of 0.028–0.062 μmol/L in seawater was yielded by inputting certain seasonal unit river flows (m3/s), or in other words, the silicate supply rate; and when the unit river flow was set to zero, meaning no river input, the silicate concentrations were between 0.05–0.69 μmol/L in the bay. In terms of the silicate supply rate, Jiaozhou Bay was divided into three parts. The division shows a given river flow could generate several different silicon levels in corresponding regions, so as to the silicon-limitation levels to the phytoplankton in these regions. Another dynamic model of river flow versus primary production was set up by which the phytoplankton primary production of 5.21–15.55 (mgC/m2·d)/(m3/s) were obtained in our case at unit river flow values via silicate concentration or primary production conversion rate. Similarly, the values of primary production of 121.98–195.33 (mgC/m2·d) were achieved at zero unit river flow condition. A primary production conversion rate reflects the sensitivity to silicon depletion so as to different phytoplankton primary production and silicon requirements by different phytoplankton assemblages in different marine areas. In addition, the authors differentiated two equations (Eqs. 1 and 2) in the models to obtain the river flow variation that determines the silicate concentration variation, and in turn, the variation of primary production. These results proved further that nutrient silicon is a limiting factor for phytoplankton growth. This study was funded by NSFC (No. 40036010), and the Director's Fund of the Beihai Sea Monitoring Center, the State Oceanic Administration.  相似文献   

4.
Analysis and comparison of Jiaozhou Bay data collected from May 1991 to February 1994 revealed the spatiotemporal variations of the ambient Si(OH)4:NO3 (Si:N) concentration rations and the seasonal variations of (Si:N) ratios in Jiaozhou Bay and showed that the Si:N ratios were <1 throughout Jiaozhou Bay in spring, autumn, and winter. These results provide further evidence that silicate limits the growth of phytoplankton (i.e. diatoms) in spring, autumn and winter. Moreover, comparison of the spatiotemporal variations of the Si:N ratio and primary production in Jiaozhou Bay suggested their close relationship. The spatiotemporal pattern of dissolved silicate matched well that of primary production in Jiaozhou Bay. Along with the environmental change of Jiaozhou Bay in the last thirty years, the N and P concentrations tended to rise, whereas Si concentration showed cyclic seasonal variations. With the variation of nutrient Si limiting the primary production in mind, the authors found that the range of values of primary production is divided into three parts: the basic value of Si limited primary production, the extent of Si limited primary production and the critical value of Si limited primary production, which can be calculated for Jiaozhou Bay by Equations (1), (2) and (3), showing that the time of the critical value of Si limitation of phytoplankton growth in Jiaozhou Bay is around November 3 to November 13 in autumn; and that the time of the critical value of Si satisfaction of phytoplankton growth in Jiaozhou Bay is around May 22 to June 7 in spring. Moreover, the calculated critical value of Si satisfactory for phytoplankton growth is 2.15–0.76 μmol/L and the critical value of Si limitation of phytoplankton growth is 1.42–0.36 μmol/L; so that the time period of Si limitation of phytoplankton growth is around November 13 to May 22 in the next year; the time period of Si satisfactory for phytoplankton growth is around June 7 to November 3. This result also explains why critical values of nutrient silicon affect phytoplankton growth in spring and autumn are different in different waters of Jiaozhou Bay and also indicates how the silicate concentration affects the phytoplankton assemblage structure. The dilution of silicate concentration by seawater exchange affects the growth of phytoplankton so that the primary production of phytoplankton declines outside Jiaozhou Bay earlier than inside Jiaozhou Bay by one and half months. This study showed that Jiaozhou Bay phytoplankton badly need silicon and respond very sensitively and rapidly to the variation of silicon. This study was funded by NSFC (No. 40036010) and subsidized by Special Funds from National Key Basic Research Program of P. R. China (G19990437), the Postdoctoral Foundation of Ocean University of Qingdao, the Director's Foundation of the Beihai Monitoring Center of the State Oceanic Administration and the Foundation of Shanghai Fisheries University.  相似文献   

5.
The standing stock and primary production of benthic microalgae on tidal flats were measured seasonally at 3 transects (Puqing, Dahengchuang and Puqi) in Yueqing Bay during 2002 2003. The results showed that the integral chlorophyll a (Chl a) concentration in tidal flat mud exhibited a seasonal variation with the order of magnitude: winter (14.0 4.2 mg m-2) > spring (13.0 6.3 mg m-2) > autumn (7.7 5.9 mg m-2) > summer (4.6 3.2 mg m-2). The primary production showed an order of magnitude: spring (270.5 224.9 mgC m-2 d-1)>winter (238.7 225.5 mgC m-2 d-1)>autumn (214.1 56.2 mgC m-2 d-1)>summer (71.6 44.6 mgC m-2 d-1). Both chlorophyll a and primary production showed maximum values in the surface layer of sediment, and decreased rapidly with increasing depth due to sun light limitation. The results of variance analysis indicated that seasonal variation and tidal flat condition affected Chl a greatly, but had no significant effect on primary production. The annual primary production of benthic microalgae on tidal flats in Yueqing Bay was estimated at 16143 tons carbon, which is sufficient to support 1.02×105 tons shellfish production. The environmental factors affecting chlorophyll and primary production on the tidal flats in Yueqing Bay were discussed. By comparing with other bays on China’s coast, it was observed that Yueqing Bay is a region with high benthic microalgae standing crop and primary production, which may be related to the type of its sediment.  相似文献   

6.
I Introduction Phytoplankton play an important role in the primary production of ocean (Ning et al., 1995). They are impor-tant biological mediators of carbon turnover in seawater ecosystems (Zhu et al., 1993). Phytoplankton in Jiaozhou Bay have been preliminarily studied on the subjects of community structure, primary productivity and carbon budget (Qian et al., 1983; Guo et al., 1992; Jiao et al., 1994). It has been found that seasonal variation of phytoplankton cell abundance presents w…  相似文献   

7.
INTRODUCTIONTheproductionofphytoplanktonisthefirsttacheintheproductionbymarineorganismsandinthemarinefoodchain .Knowledgeofprimaryproductioninmarinewatersisprerequisiteforexploitationandmanagementoftheocean’slivingresources.Theprimaryproductioninmarin…  相似文献   

8.
Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou B ay, were analyzed to determine the spatiotemporal variations in temperature, light, nutrients (NO-3-N, NO-2-N, NH+4-N, SiO2-3-Si, PO3-4-P), phytoplankton, and primary production in Jiaozhou Bay. The results indicated that only silicate correlated well in time and space with, and had important effects on, the characteristics, dynamic cycles and trends of, primary production in Jiaozhou Bay. The authors developed a corresponding dynamic model of primary production and silicate and water temperature. Eq.(1) of the model shows that the primary production variation is controlled by the nutrient Si and affected by water temp erature; that the main factor controlling the primary production is Si; that water temper ature affects the composition of the structure of phytoplankton assemblage; that the different populations of the phytoplankton assemblage occupy different ecologica l niches for C, the apparent ratio of conversion of silicate in seawater into phytoplankton biomas and D, the coefficient of water temperature's effect on phytoplankton biomass. The authors researched the silicon source of Jiaozhou Bay , the biogeochemical sediment process of the silicon, the phytoplankton predominan t species and the phytoplankton structure. The authors considered silicate a limit ing factor of primary production in Jiaozhou Bay, whose decreasing concentration of silicate from terrestrial source is supposedly due to dilution by current and up take by phytoplankton; quantified the silicate assimilated by phytoplankton, the intrins ic ratio of conversion of silicon into phytoplankton biomass, the proportion of silicate uptaken by phytoplankton and diluted by current; and found that the primary production of the phytoplankton is determined by the quantity of the silicate assimilated by them. The phenomenon of apparently high plant-nutrient concentrations but low phytoplankton biomass in some waters is reasonably explained in this paper.  相似文献   

9.
The phytoplankton reproduction capacity (PRC), as a new concept regarding chlorophyll-a and primary production (PP) is described. PRC is different from PP, carbon assimilation number (CAN) or photosynthetic rate ( P^B ) . PRC quantifies phytoplankton growth with a special consideration of the effect of seawater temperature. Observation data in Jiaozhou Bay, Qingdao, China, collected from May 1991 to February 1994 were used to analyze the horizontal distribution and seasonal variation of the PRC in Jiaozhou Bay in order to determine the characteristics, dynamic cycles and trends of phytoplankton growth in Jiaozhou Bay; and to develop a corresponding dynamic model of seawater temperature vs. PRC. Simulation curves showed that seawater temperature has a dual function of limiting and enhancing PRC. PRC‘s periodicity and fluctuation are similar to those of the seawater temperature. Nutrient silicon in Jiaozhou Bay satisfies phytoplankton growth from June 7 to November 3. When nutrients N, P and Si satisfy the phytoplankton growth and solar irradiation is sufficient, the PRC would reflect the influence of seawater temperature on phytoplankton growth. Moreover, the result quantitatively explains the scenario of one-peak or two-peak phytoplankton reproduction in Jiaozhou Bay, and also quantitatively elucidates the internal mechanism of the one- or two-peak phytoplankton reproduction in the global marine areas.  相似文献   

10.
This study showed how the daytime length in Jiaozhou Bay affected the water temperature, which in turn affected the phytoplankton growth when solar radiation was sufficient for phytoplankton photosynthesis. Jiaozhou Bay observation data collected from May 1991 to February 1994 were used to analyze the daytime length vs water temperature relationship. Our study showed that daytime length and the variation controlled the cycle of water temperature flunctuation. Should the cyclic variation curve of the daytime length be moved back for two months it would be superimposed with temperature change. The values of daytime length and temperature that calculated in the dynamical model of daytime length lag vs water temperature were consistent with observed values. The light radiation and daytime length in this model determined the photochemistry process and the enzymic catalysis process of phytoplankton photosynthesis. In addition, by considering the effect of the daytime length on water temperature and photosynthesis, we could comprehend the joint effect of daytime length, water temperature, and nutrients, on the spatiotemperal variation of primary production in Jiaozhou Bay.  相似文献   

11.
Analysis and comparison of Jiaozhou Bay data collected from May 1991 to February 1994 (12 seasonal investigations) provided by the Ecological Station of Jiaozhou Bay revealed the characteristic spatiotemporal variation of the ambient concentration Si∶DIN and Si∶16P ratios and the seasonal variation of Jiaozhou Bay Si∶DIN and Si∶16P ratios showing that the Si∶DIN ratios were <1 throughout the year in Jiaozhou Bay; and that the Si∶16P ratios were <1 throughout Jiaozhou Bay in spring, autumn and winter. The results proved that silicate limited phytoplankton growth in spring, autumn and winter in Jiaozhou Bay. Analysis of the Si∶DIN and Si∶P ratios showed that the nutrient Si has been limiting the growth of phytoplankton throughout the year in some Jiaozhou Bay waters; and that the silicate deficiency changed the phytoplankton assemblage structure. Analysis of discontinuous 1962 to 1998 nutrient data showed that there was no N or P limitation of phytoplankton growth in that period. The authors consider that the annual cyclic change of silicate limits phytoplankton growth in spring, autumn and winter every year in Jiaozhou Bay; and that in many Jiaozhou Bay waters where the phytoplankton as the predominant species need a great amount of silicate, analysis of the nutrients N or P limitation of phytoplankton growth relying only on the N and P nutrients and DIN∶P ratio could yield inaccurate conclusions. The results obtained by applying the rules of absolute and relative limitation fully support this view. The authors consider that the main function of nutrient silicon is to regulate and control the mechanism of the phytoplankton growth process in the ecological system in estuaries, bays and the sea. The authors consider that according to the evolution theory of Darwin, continuous environmental pressure gradually changes the phytoplankton assemblage's structure and the physiology of diatoms. Diatoms requiring a great deal of silicon either constantly decrease or reduce their requirement for silicon. This will cause a series of huge changes in the ecosystem so that the whole ecosystem requires continuous renewal, change and balancing. Human beings have to reduce marine pollution and enhance the capacity of continental sources to transport silicon to sustain the continuity and stability in the marine ecosystem. This study was funded by the NSFC (No. 40036010) and subsidized by Special Funds from the National Key Basic Research Program of P. R. China (G199990437), the Postdoctoral Foundation of Ocean University of Qingdao, the Director's Foundation of the Beihai Monitoring Center of the State Oceanic Administration and the Foundation of Shanghai Fisheries University.  相似文献   

12.
Trare amounts of benzene hydrocarbons obtained in Jiaozhou Bay (Qindao) were enriched bysorption on a GDX-102 column and eluted by carbon disulfide. The eluted was concenttaled and then de-temened by capillary column gas cbornatognphy.The contents of virious kinds of benzene hydrocarbons in Jiaozhou Bay coastal water were benzene(22.3-141.6)× 10~(-9)g/L, toluate (15.2-94.0) × 10~(-9) g/L, ethyl benzene(11.8-85.1)×10~(-9) g/L, p -xylene(15.2-78.5) ×10(-9) g/L, m-xylene (10.9-79.4) ×10(-9) g/L, o -xylene (12.4-80.1) x ×10(-9)g/L; iso-propyl(8.4- 73.1) x ×10(-9)g/L, n -propyl (6.9-76.4) ×10(-9) g/L, 1, 3, 5-trimethylbenzene (10.9- 35.9)×10(-9) g/L, 1,2, 4-trimethybenzene (10.0- 38.0)×10(-9) g/L, n - butydriare (8. 1 - 34.6) ×10(-9)g/L. The recovery of benzenehydrocarbons was (85.1 -95.6)%.  相似文献   

13.
1 INTRODUCTION Bioavailability to the biota and the biogeo-chemistry of trace metals in marine environment areaffected by their chemical speciation in the naturalsystem (Bruland et al., 1991; Van den Berg andDonat, 1992; Wells et al., 1998). Therefore, thesetwo parameters, the ligands concentrations andconditional stability constants, are important todetermine the complexing capacity. Sea surface microlayer (SML), the thin interfa-cial boundary between ocean and atmosphere, playsan imp…  相似文献   

14.
1 INTRODUCTIONSystematicstudyisusefulforhumanvisualizationandcomprehensionofanetworkofcomplicatedcompo nentsandprocessesinvolvingfrequentenergyflow ,consideringenergyasthebasisofbothstructureandprocess (Automa ,1 993) .Energylanguageisaconceptfordepictingasysteminwhichallphenomenaareac companiedbyenergytransformation .Thefunctionoftheecosystemovertheworlddependsontheenergyfixationbymarineplantphotosynthesis ,mostofthemarefixedbymicrophytoplanktonnearseasurfaceexposedtosunlight (Niebaken …  相似文献   

15.
The SCENTO-System was used to study the carbon dynamics between phytoplankton primary production and heterotrophic bacterial secondary production. Most of the methods used nowadays in situ for limnological synecology studies were applied. Primary production measurement showed an increasing tendency with increasing content of chlorophylla. It provided a true photosynthetic rate lying within the range of eutrophic lakes. Net EOC released from the algae ranged from 8.5 to 27.5 μg C l−1(6h)−1. Accompanying the algal products the number of bacteria increased from 1.475 ×109 to 8.074×109 cells l−1. The bacterial mean cell volume was small, between 0.0315 and 0.0548μm3. Bacterial carbon production from direct growth estimates was compared with independent calculations of bacterial growth from EOC uptake and3H-thymidine incorporation. Direct estimates were 2.97–10.0 μg Cl−1 (24h)−1 with the exception of a zero-growth on the third day. EOC uptake was 123.5–191.0 μg Cl−1 (6h)−1. That calculated from3H-thymidine incorporation was 0.2–0.5 μg Cl−1 (6h)−1.14C-glucose dark uptake ran parallel to the increasing bacterial biomass. The respiration of glucose was 6.5% (avg.) of the gross uptake. Since the system operated without grazing pressure, a real carbon flow from primary production to bacterial secondary production could be observed.  相似文献   

16.
Dilution incubations and Calanus sinicus addition incubations were simultaneously conducted at five stations in the Yellow Sea in June of 2004 to evaluate the impact of microzooplankton and Calanus sinicus on phytoplankton based on the Chlorophyll a (Chl-a) levels. The Chl-a growth rates (k) ranged from 0.60–1.67 d−1, while microzooplankton grazed the Chl-a at rates (g) of 0.29–0.62 dt-1. The addition of C. sinicus enhanced the Chl-a growth rate (Z) by 0.004–0.037 d−1 ind.−1 L. C. sinicus abundance ranged from 84.1–160.9 ind. m−3, which occupied 90.7%–99.1% of the copepod (>500 μm) population. The in-situ increase in phytoplankton by C. sinicus community was estimated to be 0.000 4–0.005 9 d−1. These results showed that microzooplankton were the main grazers of phytoplankton, while C. sinicus induced a slight increase in the levels of phytoplankton.  相似文献   

17.
INTRODUCTIONNandPinputtedintoJiaozhouBaybyriversandbysewageeffluentsofcities ,havemadetheBaybecomemoreandmoreeutrophicdaybyday .Shen ( 1994)thoughtthatphytoplanktongrowthwaslimitedbythechangefromnitrogentophosphorous ;andthatthesilicateconcentrationinJiaozh…  相似文献   

18.
A dynamic box model of bioactive elements in the southern Taiwan Strait   总被引:3,自引:0,他引:3  
A dynamic box model was applied to study the characteristics of biogeochemical cycling of PO_4-P,NO_3-N,AOU,POC and PON in the southern Taiwan Strait region based on field data of the"Minnan Taiwan Bank Fishing Ground Upwelling Ecosystem Study" during the period of Dec.1987-Nov.1988.According to the unique hydrological and topographical features of the region,six boxesand three layers were considered in the model.The variation rates and fluxes of elements induced by hor-izontal current,upwelling,by diffusion,sinking of particles and biogeochemical processes were estimatedrespectively.Results further confirmed that upwellings had important effects in this region.Thenearshore upwelling areas had net input fluxes of nutrients brought by upwelling water,also had high de-pletion rates of nutrients and production rates of particulate organic matter and dissolved oxygen.Theabnormal net production of nutrients in the middle layer(10-30m) indicated the important role of bacte-ria in this high production region.Th  相似文献   

19.
The abundance and biomass of benthic heterotrophic bacteria were investigated for the 4 typical sampling stations in the northern muddy part of Jiaozhou Bay, estuary of the Dagu River, raft culturing and nearby areas of Huangdao in March, June, August and December, 2002. The abundance and biomass range from 0.98×107 to 16.87×107 cells g−1 sediment and 0.45 to 7.08 μg C g−1 sediment, respectively. Correlation analysis showed that heterotrophic bacterial abundance and biomass are significantly correlated to water temperature (R=0.79 and 0.83, respectively,P<0.01).  相似文献   

20.
Batch culture experiments were conducted with a red tide dinoflagellateScrippsiella trochoidea (Stein) Loeblch III collected from Jiaozhou Bay, Shangdong, China. Growth rates and oellular Chl—a were measured in media with iron and manganese ion concentrations controlled at different levels using EdTA-trace metal buffer systems. Cell density increased 3.2 times to 6.5 times over the range of lowest (0 mol/L) to highest (10−5 mol/L) iron and manganese ion concentrations. The range of cell density response was much lower than the range of total available iron and manganese, which was >100—fold that of Fe. This nonlinear relationship indicates that the cells adapt to make more efficient use of iron and manganese under limiting conditions. The cellular Chl—a content maximized after 3 days incubation and then decreased gradually under either iron or manganese limitation conditions. It indicated that the algae gained higher photosynthesis ability when transferred to a new environment. Growth responses to iron and manganese limitation can be both modeled according to the equation of Monod. The half—saturation constant for growth,k, is 4.6×10−8 mol/L for Fe and 5.1×10−8 mol/L for Mn. Our results showed that the iron availability in Jiaozhou Bay does not limit the growth ofS. trochoidea. Contribution No. 2831 from the Institute of Oceanology, Chinese Academy of Sciences. Project 9389008 supported by NSFC; Study supported by PDB6.  相似文献   

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