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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.
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   

3.
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   

4.
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   

5.
Autumn photoproduction of carbon monoxide in Jiaozhou Bay,China   总被引：1，自引：0，他引：1  
Carbon monoxide(CO) plays a significant role in global warming and atmospheric chemistry. Global oceans are net natural sources of atmospheric CO. CO at surface ocean is primarily produced from the photochemical degradation of chromophoric dissolved organic matter(CDOM). In this study, the effects of photobleaching, temperature and the origin(terrestrial or marine) of CDOM on the apparent quantum yields(AQY) of CO were studied for seawater samples collected from Jiaozhou Bay. Our results demonstrat that photobleaching, temperature and the origin of CDOM strongly affected the efficiency of CO photoproduction. The concentration, absorbance and fluorescence of CDOM exponentially decreased with increasing light dose. Terrestrial riverine organic matter could be more prone to photodegradation than the marine algae-derived one. The relationships between CO AQY and the dissolved organic carbon-specific absorption coefficient at 254 nm for the photobleaching study were nonlinear, whereas those of the original samples were strongly linear. This suggests that: 1) terrestrial riverine CDOM was more efficient than marine algae-derived CDOM for CO photoproduction; 2) aromatic and olefinic moieties of the CDOM pool were affected more strongly by degradation processes than by aliphatic ones. Water temperature and the origin of CDOM strongly affected the efficiency of CO photoproduction. The photoproduction rate of CO in autumn was estimated to be 31.98 μmol m-2 d-1 and the total DOC photomineralization was equivalent to 3.25%- 6.35% of primary production in Jiaozhou Bay. Our results indicate that CO photochemistry in coastal areas is important for oceanic carbon cycle.  相似文献   

6.
Sharpies‘ 1-D physical rrozlel maploying tide-wind driven turbulence closure and surface heating-cooling physics, was coupled with an eculogical rnodet with 9-biochemical components: phytoplankton, zooplankton, shellfish, autotmphic and heterotrophic bacterioplankton, dissolved organic carbon (DOC), suspended detritus and sinking particles to simulate the armual evolution of ecosystem in thecentral part of Jiaozhou Bay. The coupled modeling results showed that the phytoplankton shading effectcould reduce seawater temperamre by 2℃, so that photosynthesis efficiency should be less than 8% ; that the loss of phytoplankton by zooplankton grazing in winter tended to be compensated by phytoplankton advection and diffusion from the otrtside of the Bay; that the incidem irradiance intensity could be the mostimportant factor for phytoplankton grcr, wth rate; and that it was the bacterial secondary prnduction that maintained the maximum zooplankton biomass in winter usually observed in the 1990s, indicating that themicrobial food loop was extremely important for ecosystem study of Jiaozhou Bay.  相似文献   

7.
A zero-dimensional box model (PNCMjzb) with six state variables (ammonium, nitrate, dissolved organic nitrogen, phytoplankton, zooplankton and detritus) was developed to study nitrogen cycling in the Jiaozhou Bay pelagic ecosystem. The dominant processes within these compartments are considered with nitrogen as flow currency. Phytoplankton and zooplankton are treated as separate state variables, assuming that the species composition was dominated by two or three species the dynamic constants of which are similar and that they represent the entire plankton community. The microbial loop has not been integrated explicitly in the model. The turnover of bacteria is included implicitly in processes such as detritus decomposition, DON remineralization, pelagic nitrification and denitrification. The model is driven by two forcing variables, viz. water temperature and light intensity. Historical data from the1980s and 1990s were compiled and used for model calibration. In this paper (part Ⅰ), the consideration of every main compartment in the model is interpreted in detail. And the applied equations and parameters are presented. The main results from the simulations together with discussion about phytoplankton dynamics and primary production in Jiaozhou Bay are presented in the next paper (part Ⅱ).  相似文献   

8.
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   

9.
Biomarkers including brassicasterol, dinosterol and alkenone in sediments are used as indicators to reconstruct changes to the phytoplankton community in surface and sub-aerial sediments of Prydz Bay, Antarctica. The results indicate that the bio- marker records in surface and core sediment samples changed with time and space. The total content of phytoplankton biomarkers ranges from 391.0--1 470.6 ng.g-l. The phytoplankton biomass has increased in Prydz Bay over the past 100 years. This variation may be mainly related with climate change in the region. The total biomarker contents in surface sediments from 5 stations in Prydz Bay are in the range of 215.8--1 294.3 ng.g4. The phytoplankton biomass in Prydz Bay is higher than that outside of the bay. This is similar to the distributions of chlorophyll a, organic carbon and biogenic silica in surface waters determined through in situ investigation. Such consistency indicates a coupling between the bottom of the ocean and biogeochemical processes in the upper water.  相似文献   

10.
Carbon biomass,carbon-to-chlorophyll a ratio(C:Chl a),and the growth rate of phytoplankton cells were studied during four seasonal cruises in 2017 and 2018 in Jiaozhou B ay,China.Water samples were collected from 12 stations,and phytoplankton carbon biomass(phyto-C) was estimated from microscopemeasured cell volumes.The phyto-C ranged from 5.05 to 78.52 μg C/L in the bay,and it constituted a mean of 38.16% of the total particulate organic carbon in the bay.High phyto-C values appeared mostly in the northern or northeastern bay.Diatom carbon was predominant during all four cruises.Dinoflagellate carbon contributed much less(30%) to the total phyto-C,and high values appeared often in the outer bay.The C:Chl a of phytoplankton cells varied from 11.50 to 61.45(mean 3 1.66),and high values appeared in the outer bay during all four seasons.The phyto-C was also used to calculate the intrinsic growth rates of phytoplankton cells in the bay,and phytoplankton growth rates ranged from 0.56 to 1.96/d;the rate was highest in summer(mean 1.79/d),followed by that in fall(mean 1.24/d) and spring(mean 1.17/d),and the rate was lowest in winter(mean 0.77/d).Temperature and silicate concentration were found to be the determining factors of phytoplankton growth rates in the bay.To our knowledge,this study is the first report on phytoplankton carbon biomass and C:Chl a based on water samples in Jiaozhou B ay,and it will provide useful information for studies on carbon-based food web calculations and carbon-based ecosystem models in the bay.  相似文献   

11.
Using ICP-AES with microwave digestion, we determined the concentrations of 16 trace elements in oysters from six sampling points in Jiaozhou Bay.The distributions of the wholesome elements Zn, Fe and Mn, and heavy metals such as As,Cd,Hg and Pb were studied.The oysters collected are all rich in the wholesome trace elements,and the oysters from Licun River have the highest concentrations of the three wholesome trace elements.The concentrations of heavy metals in oysters from Licun River are the highest and those from Hongdao are the lowest. Compared with the domestic and foreign sea-areas,the heavy metal contents in the oysters from Jiaozhou Bay are less in amount than those from some developed countries, and more than those in Southeast China.This implies that the Jiaozhou Bay’s oysters have been polluted by the environment to some extent.  相似文献   

12.
In vivo fluorescence methods are efficient tools for studying the distribution of phytoplankton in nature.Different algae species usually have different pigments with different ratios,which results in different fluorescence emission spectra.Based on multiple excitation wavelength fluorescence emission spectra,a discrimination technique is established in this study.The discrimination method,established by multivariate linear regression and weighted least-squares,was used to differentiate the samples cultured in the laboratory and collected from Jiaozhou Bay near Qingdao at the division level.The correctly discriminated samples were ≥ 86% for single algae samples,≥ 88% for simulatively mixed ones,≥ 91% for physically mixed ones and 100% for samples collected from Jiaozhou Bay.The result in this research is more definite for the physically mixed samples in the laboratory.The method described here can be employed to monitor the phytoplankton population in the marine environment.  相似文献   

13.
Trophic structure of fish communities is fundamental for ecosystem-based fisheries management, and trophic spectrum classifies fishes by their positions in food web, which provides a simple summary on the trophic structure and ecosystem function. In this study, both fish biomass and abundance trophic spectra were constructed to study the spatial and seasonal variations in the trophic structure of demersal fish assemblages in Jiaozhou Bay, China. Data were collected from four seasonal bottom trawl surveys in Jiaozhou Bay from February to November in 2011. Trophic levels(TLs) of fishes were determined by nitrogen stable isotope analysis. This study indicated that most of these trophic spectra had a single peak at trophic level(TL) of 3.4–3.7, suggesting that demersal fish assemblages of Jiaozhou Bay were dominated by secondary consumers(eg. Pholis fangi and Amblychaeturichthys hexanema). The spatial and seasonal variations of trophic spectra of Jiaozhou Bay reflected the influence of fish reproduction, fishing pressure and migration of fishes. Two-way analysis of variance(ANOVA) showed that seasonal variations in trophic spectra in Jiaozhou Bay were significant(P 0.05), but variations among different areas were not significant( P 0.05). The trophic spectrum has been proved to be a useful tool to monitor the trophic structure of fish assemblages. This study highlighted the comprehensive application of fish biomass and abundance trophic spectra in the study on trophic structure of fish assemblages.  相似文献   

14.
An environmental capacity model for the petroleum hydrocarbon pollutions (PHs) in Jiaozhou Bay is constructed based on field surveys, mesocosm, and parallel laboratory experiments. Simulated results of PHs seasonal successions in 2003 match the field surveys of Jiaozhou Bay resaonably well with a highest value in July. The Monte Carlo analysis confirms that the variation of PHs concentration significantly correlates with the river input. The water body in the bay is reasonably subjected to self-purification processes, such as volatilization to the atmosphere, biodegradation by microorganism, and transport to the Yellow Sea by water exchange. The environmental capacity of PHs in Jiaozhou Bay is 1500 tons per year IF the seawater quality criterion (Grade Ⅰ/Ⅱ, 0.05 mgL-1) in the region is to be satisfied. The contribution to self-purification by volatilization, biodegradation, and transport to the Yellow Sea accounts for 48%, 28%, and 23%, respectively, which make these three processes the main ways of PHs purification in Jiaozhou Bay.  相似文献   

15.
Recent observations support an emerging paradigm that climate variability dominates nutrient enrichment in costal eco-systems, which can explain seasonal and inter-annual variability of phytoplankton community composition, biomass (Chl-a), and primary production (PP). In this paper, we combined observation and modeling to investigate the regulation of phytoplankton dynamics in Chesapeake Bay. The year we chose is 1996 that has high river runoff and is usually called a ’wet year’. A 3-D physical-biogeochemical model based on ROMS was developed to simulate the seasonal cycle and the regional distributions of phytoplankton biomass and primary production in Chesapeake Bay. Based on the model results, NO3 presents a strong contrast to the river nitrate load during spring and the highest concentration in the bay reaches around 80 mmol Nm-3 . Compared with the normal year, phytoplankton bloom in spring of 1996 appears in lower latitudes with a higher concentration. Quantitative comparison between the modeled and observed seasonal averaged dissolved inorganic nitrogen concentrations shows that the model produces reliable results. The correlation coefficient r2 for all quantities exceeds 0.95, and the skill parameter for the four seasons is all above 0.95.  相似文献   

16.
In this study, we investigated the distributions of sea-surface suspended particulate organic carbon （POC） and its stable isotope （δ13C POC） in Prydz Bay, Antarctica, and examined the factors influencing their distribution, sources, and transport. We used measurements collected from 61 stations in Prydz Bay during the 29th Chinese National Antarctic Research Expedition, in combination with remote sensing data on sea surface temperature （SST）, chlorophyll a concentration, and sea ice coverage. The POC concentration in the surface waters of Prydz Bay was 0.28-0.84 mg.L-1, with an average concentration of 0.48 mg.L-1. The δ13C POC value ranged from -29.68‰ to -26.30‰, with an average of-28.01‰. The concentration of suspended POC was highest in near-shore areas and in western Prydz Bay. The POC concentration was correlated with chlorophyll a concentration and sea ice coverage, suggesting that POC was associated with phytoplankton production in local water columns, while the growth of phytoplankton was obviously affected by sea ice coverage. The δ13C poc value in suspended particles decreased gradually towards the outer waters of Prydz Bay, while in eastern Prydz Bay the δ13Cpoc value become gradually more negative from nearshore to deep-water areas, suggesting that δ13C poc was mainly influenced by CO2 fixation by phytoplankton. The δ13C POC value in suspended particles near Zhongshan Station was significantly negative, possibly as a result of the input of terrigenous organic matter and changes in the phytoplankton species composition in the nearshore area.  相似文献   

17.
Manila clam(Ruditapes philippinarum) was monthly sampled from its benthic aquaculture area in Jiaozhou Bay from May 2009 to June 2010. The annual variations of major elemental composition, organic content, fatness and element ratio of Manila clam were examined. The element removal effect of clam farming in Jiaozhou Bay was analyzed based on natural mortality and clam harvest. The results indicated that the variation trend of carbon content in shell(Cshell) was similar to that in clam(Cclam). Such a variation was higher in summer and autumn than in other seasons, which ranged from 9.10 ± 0.13 to 10.38 ± 0.09 mmol g-1 and from 11.28 ± 0.29 to 12.36 ± 0.06 mmol g-1, respectively. Carbon content of flesh(Cflesh) showed an opposite variation trend to that of shell in most months, varying from 29.42 ± 0.05 to 33.64 ± 0.62 mmol g-1. Nitrogen content of shell(Nshell) and flesh(Nflesh) changed seasonally, which was relatively low in spring and summer. Nshell and Nflesh varied from 0.07 ± 0.009 to 0.14 ± 0.009 mmol g-1 and from 5.46 ± 0.12 to 7.39 ± 0.43 mmol g-1, respectively. Total nitrogen content of clam ranged from 0.50 ± 0.003 to 0.76 ± 0.10 mmol g-1 with a falling tend except for a high value in March 2010. Phosphorus content of clam(Nclam) fluctuated largely, while phosphorus content of shell(Pshell) was less varied than that of flesh(Pflesh). Pshell varied from 0.006 ± 0.001 to 0.016 ± 0.001 mmol g-1; while Pflesh fluctuated between 0.058 ± 0.017 and 0.293 ± 0.029 mmol g-1. Pclam ranged from 0.015 ± 0.002 to 0.041 ± 0.006 mmol g-1. Carbon and nitrogen content were slightly affected by shell length, width or height. Elemental contents were closely related to the reproduction cycle. The removal amounts of carbon, nitrogen and phosphorus from clam harvest and natural death in Jiaozhou Bay were 2.92×104 t, 1420 t and 145 t, respectively. The nutrient removal may aid to reduce the concentrations of nitrogen and phosphorus, the main causes of eutrophication, and to maintain the ecosystem health of Jiaozhou Bay.  相似文献   

18.
Studies on the diversity and distribution of bacterial populations will improve the overall understanding of the global patterns of marine bacteria and help to comprehend local biochemical processes and environments. We evaluated the composition and the dynamics of bacterial communities in the sediment of Jiaozhou Bay (China) using PCR-denaturing gradient gel electrophoresis (DGGE). Sediment samples were collected from 10 different sites in May, August, and November 2008 and in February 2009. There was significant temporal variation in bacterial community composition at all sites. However, the spatial variation was very small. The DGGE analyses of bacterial communities were used to divide the 10 stations into three types. Canonical correspondence analysis (CCA) revealed that the changes in bacterial communities were driven by sediment properties. Sequence analysis of DGGE band-derived 16S rRNA gene fragments revealed that the dominant bacterial groups in the sediment were of the classes γ-proteobacteria and δ-proteobacteria and phyla Bacteroidetes and Nitrospirae. Our results provide considerable insight into the bacterial community structure in Jiaozhou Bay, China.  相似文献   

19.
Methane(CH_4) is an important greenhouse gas and oceans are net sources of atmospheric CH_4. The effects of environmental factors on the CH_4 variation during different phases of the spring algal blooms were examined during two cruises conducted in the Yellow Sea(YS) from February to April of 2009. During the pre-bloom period from February to March, low CH_4 saturation( 134%) was observed in the surface water, except at two nearshore stations where the CH_4 levels were above 140% in March due to mixing with the coastal water. During the bloom period, CH_4 increased obviously at two bloom-tracking stations, especially at the surface with mean saturations of 140% and 170%. The increase in CH_4 concentration/saturation is thought to be the result of in situ CH_4 production. The particulate organic carbon(POC) and chlorophyll a contents were believed to be important factors that influenced the CH_4 production. In addition, the presence of different dominant phytoplankton species and the grazing pressure may have stimulated the CH_4 production by supplying potential methanogenic substrates(such as dimethylsulphoniopropionate(DMSP)). Both the incubation data and the in situ estimations further evidenced the significant influence of the spring blooms on the CH_4 production. The calculated sea-to-air CH_4 fluxes during the bloom period were not significantly higher than those during the pre-bloom period despite the bloom-increased CH_4 saturation. This is due to the variation in physical forcing(such as wind speed), which is the main driver for determining the CH_4 flux. Finally, we estimated the annual CH_4 flux in the YS as 9.0 μmol m~(-2) d~(-1); the findings suggest that the YS is a natural source of atmospheric CH_4.  相似文献   

20.
A simple diagnostic simulation of the annual cycling of the surface specific photosynthesis rate (SPR) in Jiaazhou Bay is described in this paper. Light intensity, temperature and nutrients(nitrate ammonia, phosphate) were considered as main factors controlling photosynthesis of phytoplankton and were introduced into the model by different function equations. The simulated variation ofspecific photosynthesis rate coincided with the measured data. Analysis of the effect of every factor onphotosynthesis indicated that the variation of photosynthesis rate was controlled by all these three factors,while temperature showed good correlation with SPR as measurement showed. This diagnostic simulationyielded the values of some parameter relating with the photosynthesis in Jiaozhou Bay.  相似文献   

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