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在三维海洋模式POM基础上建立水质模型,采用中心差分格式、迎风格式以及Smolarkiewicz迎风格式离散物质输运方程.以三维理想水槽中连续源排放的浓度场预测为例,分析3种离散格式求解所得的浓度场.结果表明,3种格式的数值解与解析解的偏差均小于20%.中心差分格式会引起解的震荡,导致物质的反向输移,出现浓度负值.迎风格式能够保证浓度的正值,但该格式带来的数值耗散导致数值解与解析解偏离较大.Smolarkiewicz迎风格式在普通迎风格式基础上引入抗扩散流速,经多次叠代,能有效降低计算中的数值耗散,提高了计算精度. 相似文献
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对水中物质的形态形式、分布变化及界面交换的研究是当前国际海洋湖沼化学研究的趋势。由于海洋湖沼物质组分的极度复杂与超痕量,而且痕量体系常常不处在热力学平衡状态,因而海洋湖沼化学家们尽管使用了所有现代分析化学技术和物理化学手段,但海洋湖沼痕量物质的循环大都还是谜,这需要通过发展新方法来测定和判明物质的形式、转移过程和通量。 相似文献
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珠江口及邻近海域水质状况分析 总被引：7，自引：2，他引：7
为了解决年来珠江口水域的环境质量，及该水域与其邻近水域的环境质量差异，本文利用１９９３年有关环境调查数据，选用适当的评价模式，对主要污染物的特征值进行了统计，计算。根据水域的环境特点，划分出六个评价区，对主要污染物质进行分析、比较和评价，对各区水质进行综合评价，评价结果表明，珠江口及其邻近水域的主要污染物质为无机氮和油类，珠江口水域水质污染较其邻近水域严重，珠江口北部较珠江口南部水域水质差。 相似文献
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长江口潮间带九段沙浅滩潮水沟形态分析 总被引：3，自引：1，他引：2
潮水沟演化是潮滩滩面对环境动力和生物过程的适应,分析潮水沟的形态特征有助于反推解读滩面的响应机制。借助于滩面水位高程计算模型和参数统计分析,提出九段沙上沙滩面潮水沟存在集中和分散两种发育模式。与分散模式相比,集中模式的水动力条件更强,潮沟数量更少,等级更高,规模更大。在研究区内,单支潮水沟的汇水形式彼此不同,但两种模式的总体汇水形式相近,潮水沟均以显著线性关系随汇水面积增大而扩展,最后两侧滩面产生同等的沟化程度。 相似文献
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河口三角洲、湿地及其邻近海域生态系统的水质污染在全世界范围内普遍存在,其主要原因是过量的无机营养盐或有机物、垃圾、有毒物质、病原体等通过陆地径流及排污口输入到河口及近海,引起水体富营养化、有害元素或病原体污染,给河口生态系统带来危害,从这4个方面分析了水质问题的起因和后果,并提出了相应的治理措施. 相似文献
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《中国海洋大学学报(自然科学版)》2021,(1)
为研究虹鳟(Oncorhynchus mykiss)体内土腥味物质的分布规律及其与养殖水质的关系,本文比较了不同规格虹鳟以及虹鳟不同组织中的二甲基异茨醇(2-methylisoborneol,MIB)和土臭素(Geosmin,GSM)含量;比较了养殖虹鳟、大西洋鲑(Salmo salar)和银鲑(O.kisutch)体内的MIB和GSM含量及其养殖环境的水质情况,分析了鱼体内MIB和GSM含量与水质的相关性。研究表明,虹鳟背肌中MIB和GSM含量随鱼体规格增大而升高;虹鳟肝脏中MIB和GSM含量显著高于背肌和鱼皮(P0.05),鱼皮中MIB和GSM含量最低。相关性分析显示,鱼体内MIB含量与水温、pH呈显著正相关(P0.05),GSM含量与氨氮、溶解性活性磷及总磷显著正相关(P0.05)。研究结果表明,虹鳟体内土腥味物质的分布因鱼体规格和组织不同而异,鱼体内的土腥味物质与水质有关。 相似文献
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Modelling nitrogen and phosphorus cycles and dissolved oxygen in the Zhujiang Estuary Ⅰ. Model development 总被引：1，自引：0，他引：1
wrmcrloxHuman activities related to the population growth and developrnent of industry and rnwhci-pality have led to the incrouing hadings of various POllutants into estudries during the past fewdecades. These increasing edlutant lOadings have caused declined estuallne hedth which can bemereured by a vdriety of indices. In order to obtain solutions to environrnent problerns, re-sources manageTnnt apencies are supporting a holistic approach to envirorirnental management.An effcient strategy t… 相似文献
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Kenichiro Hamada Naoko Ueda Machiko Yamada Kuninao Tada Shigeru Montani 《Journal of Oceanography》2012,68(1):173-182
Biologically important nutrient concentrations in Dokai Bay have declined as a result of reductions in anthropogenic inputs
of total nitrogen and total phosphorus. A decrease in nutrient concentrations affects phytoplankton growth, thereby changing
the biochemical characteristics of autochthonous particulate matter. We therefore investigated changes in the C/N/P molar
ratio of suspended particulate matter (SPM) in the summer, when phytoplankton growth is vigorous, before environmental quality
standards (EQSs) were attained (1995–1998) and afterward (2006–2009). We found that the ratio of particulate organic nitrogen
(PON) to particulate phosphorus (PP) changed in conjunction with changes in the ratio of dissolved inorganic nitrogen to dissolved
inorganic phosphorus (DIP) that resulted from reductions in nutrient loading. Furthermore, we suggest that because the DIP
concentration in seawater was high before EQSs were attained, inorganic phosphorus was possibly adsorbed onto SPM. After the
attainment of EQSs, however, the DIP concentration fell, and PON/PP was high. Phosphorus limitation of phytoplankton growth
in the mouth of the bay may explain the high PON/PP ratios after EQS attainment. 相似文献
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Based on a hydrodynamic-ecological model, the temperature, salinity, current, phytoplankton(Chl a),zooplankton, and nutrient(dissolved inorganic nitrogen, DIN, and dissolved inorganic phosphorous, DIP)distributions in the Beibu Gulf were simulated and the nutrient budget of 2015 was quantitatively analyzed. The simulated results show that interface processes and monsoons significantly influence the ecological processes in the gulf. The concentrations of DIN, DIP, phytoplankton and zooplankton are generally higher in the eastern and northern gulf than that in the western and southern gulf. The key regions affected by ecological processes are the Qiongzhou Strait in winter and autumn and the estuaries along the Guangxi coast and the Red River in summer.In most of the studied domains, biochemical processes contribute more to the nutrient budget than do physical processes, and the DIN and DIP increase over the year. Phytoplankton plays an important role in the nutrient budget; phytoplankton photosynthetic uptake is the nutrient sink, phytoplankton dead cellular release is the largest source of DIN, and phytoplankton respiration is the largest source of DIP. The nutrient flux in the connected sections of the Beibu Gulf and open South China Sea(SCS) inflows from the east and outflows to the south. There are 113 709 t of DIN and 5 277 t of DIP imported from the open SCS to the gulf year-around. 相似文献
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Barbamarco Lagoon (area = 7 km2) is in the Po River Delta, adjoining the Northern Adriatic Sea, and supports a commercially valuable clam (Tapes philippinarum) fishery. This study investigated interactions of the lagoon with adjacent coastal waters and inland riverine inputs by modelling both the lagoon and the Northern Adriatic Sea, using a coupled three-dimensional (3D) hydrodynamic-ecological model (ELCOM-CAEDYM) adapted to include the clam population. The clam model accounted for carbon (C), nitrogen (N) and phosphorus (P) biomass in the benthos through parameterisations for filtration, excretion, egestion, respiration, mortality, and harvesting. Multiple clam size classes were included in a new population dynamics sub-model. Output from the coupled model was validated against hydrodynamic and water quality data from intensive field sampling and routine monitoring. Time scales of tidal flushing, primary production and clam grazing were investigated with the model to demonstrate that food supply to clam populations is dominated by phytoplankton inputs from the Northern Adriatic Sea. Effects of clam cultivation on nutrient concentrations and phytoplankton biomass in Barbamarco Lagoon were primarily localised, with strong tidal flushing minimising impacts of clam filtration on lagoon-wide nutrient concentrations at current clam stocking levels. Clam populations were found to alter the cycling of nutrients in the system, causing the lagoon to become a net sink for particulate organic matter and to export dissolved organic matter to the adjacent sea via tidal flushing. Ecosystem health and sensitivity of nutrient cycles to clam cultivation are important considerations for the long term sustainable management and potential expansion of the fishery. 相似文献
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Suhaimi Suratman Keith Weston Naomi Greenwood David B. Sivyer David J. Pearce Tim Jickells 《Estuarine, Coastal and Shelf Science》2010
The aim of this study was to investigate the cycling of dissolved inorganic and organic nutrients using moored instrumented buoys (SmartBuoys) during the spring bloom in the North Sea. The instrumentation on the buoys enabled high frequency measurements of water-column integrated irradiance and in situ chlorophyll to be made, and also preserved water sample collection which were used for dissolved inorganic and organic nutrient analyses. The SmartBuoys were located in the year-round well-mixed plume zone associated with the River Thames and in the summer stratified central North Sea. These site locations allowed comparison of nutrient concentrations and cycling, and spring bloom development at two contrasting sites. The spring bloom was expected to be initiated at both stations due to increasing insolation and decreasing suspended load leading to higher water-column integrated irradiance. Due to differences in suspended load between the sites, the spring bloom started ∼2 months earlier in the central North Sea. The spring bloom in the Thames plume also resulted in higher maximum phytoplankton biomass due to the higher pre-bloom nutrient concentrations associated with riverine input. The use of SmartBuoys is also shown to allow the cycling of dissolved organic nutrients to be examined over the critical, and often undersampled, spring bloom period. Dissolved Organic Nitrogen (DON) clearly increased during the spring bloom in the central North Sea compared to winter concentrations. DON also increased in the Thames plume although showing greater winter variability related to higher riverine and sedimentary dissolved organic matter input at this shallow (∼18 m) coastal site. DON increase during the spring bloom was therefore related to primary production at both sites probably due to active release by phytoplankton. At both stations DON decreased to pre-bloom concentrations as the bloom declined suggesting the released DON was bioavailable and removed due to heterotrophic uptake and production. The preserved nutrient samples from the central North Sea site were also suitable for Dissolved Organic Phosphorus (DOP) analysis due to their low suspended load with similar trends and cycling to DON, albeit at lower concentrations. This suggested similar processes controlling both DON and DOP. The variable timing of short term events such as the spring bloom makes sampling away from coastal regions difficult without the use of autonomous technology. This study demonstrates for the first time the applicability of using preserved samples from automated buoys for the measurement of dissolved organic nutrients. 相似文献
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Variation of dissolved organic matter and fluorescence characteristics before,during and after phytoplankton bloom 总被引：3，自引：0，他引：3
Marut Suksomjit Seiya Nagao Kazuhiko Ichimi Tatsuo Yamada Kuninao Tada 《Journal of Oceanography》2009,65(6):835-846
The variation of dissolved organic matter (DOM) and fluorescence characteristics during the phytoplankton bloom were investigated
in Yashima Bay, at the eastern part of the Seto Inland Sea, Japan. We found significant accumulations of dissolved organic
carbon (DOC), dissolved organic nitrogen (DON), chromophoric dissolved organic matter (CDOM) fluorescence, and UV260 during the phytoplankton bloom period in 2005, although lower accumulations of DOC and DON and only increases of CDOM fluorescence
were observed during the bloom period in 2006. Little or no correlation between DOM and phytoplankton abundance might be due
to the composition of DOM, which is a complex mixture of organic materials. The 3D-EEM results revealed that the DOM produced
around the phytoplankton bloom period contained tyrosine, tryptophan, and humic-like substances. Our results showed that the
occurrence of phytoplankton bloom contributed to the production of DOM in coastal water but the DOM accumulation depended
on the type of phytoplankton bloom, the phytoplankton species in particular. From our results, we concluded that phytoplankton
have a great role in the dynamics of DOM as a producer in a coastal environment. 相似文献
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Harilaos Loukos Bruce Frost D.E. Harrison James W. Murray 《Deep Sea Research Part II: Topical Studies in Oceanography》1997,44(9-10)
We construct a one-dimensional ecosystem model (nitrate, ammonium, phytoplankton, zooplnakton and detritus) with simple physics and biology in order to focus on the structural relations and intrinsic properties of the food web that characterizes the biological regime in the central equatorial Pacific at 140°W. When possible, data collected during the EgPac and other cruises were used to calibrate model parameters for two simulations that differ in the limiting nutrient, i.e. nitrogen or iron. Both simulations show annual results in good agreement with the data, but phytoplankton biomass and primary production show a more pronounced annual variability when iron is used as the limiting nutrient. This more realistically reproduces the variability of biological production and illustrates the greater coupling between vertical physical processes and biological production when the limiting nutrient is iron rather than nitrogen. The iron simulation also illustrates how iron supply controls primary production variability, how grazingbalances primary production and controls phytoplankton biomass, and how both iron supply and grazingcontrol primary production. These results suggest that it is not possible to capture primary production variability in the central equatorial Pacific with biological models using nitrogen as the limiting nutrient. Other indirect results of this modeling study were: (1) partitioning of export production between dissolved and particulate matter is almost equal, suggesting that the importance of DOC export may have been previously overestimated; (2) lateral export of live biomass has to be taken into account in order to balance the nitrogen budget on the equator at 140°W; and (3) preferential uptake of ammonium (i.e. nitrate uptake inhibition by ammonium) associated with high regeneration of nitrogen (low f ratio as a consequence of the food web structure imposed by iron limitation) largely accounts for the surface build-up of upwelled nitrate. 相似文献
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The European Regional Seas Ecosystem Model (ERSEM) has been coupled with a two-dimensional depth-averaged transport model of the Humber plume region and run to simulate 1988–1989. Simulations of the spatial and temporal variations in chlorophyll-a, nitrate, phosphate and suspended particulate matter distributions in winter, spring and summer show how the development of the spring bloom and subsequent maintenance of primary production is controlled by the physicochemical environment of the plume zone. Results are also shown for two stations, one characterised by the high nutrient and suspended matter concentrations of the plume and the other by the relatively low nutrient and sediment concentrations of the offshore waters. The modelled net primary production at the plume site was 105 g C m−2 a−1 and 127 g C m−2 a−1 offshore. Primary production was controlled by light limitation between October and March and by the availability of nutrients during the rest of the year. The phytoplankton nutrient demand is met by in-situ recycling processes during the summer. The likely effect of increasing and decreasing anthropogenic riverine inputs of nitrate and phosphate upon ecosystem function was also investigated. Modelling experiments indicate that increasing the nitrogen to silicate ratio in freshwater inputs increased the production of non-siliceous phytoplankton in the plume. The results of this model have been used to calculate the annual and quarterly mass balances describing the usage of inorganic nitrogen, phosphate and silicate within the plume zone for the period of the NERC North Sea survey (September 1988 to October 1989). The modelled Humber plume retains 3.9% of the freshwater dissolved inorganic nitrogen, 2.2% of the freshwater phosphate and 1.3% of the freshwater silicate input over the simulated seasonal cycle. The remainder is transported into the southern North Sea in either dissolved or particulate form. The reliability of these results is discussed. 相似文献
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Realistic modelling of marine ecosystems is necessary for improving our understanding of the ocean’s biogeochemical state and for predicting their response to anthropic perturbations. An essential step in achieving this task is the use of mechanistic formulations to describe the biogeochemical processes involved in the dynamics of marine pelagic ecosystems. This study provides a review on some modelling strategies for some of the key processes involved in the dynamics of phytoplankton. It encompasses the most advanced work in terms of mechanistic understanding and, therefore, mainly deals with photosynthesis (including photoacclimation and photoinhibition), respiration, and nutrient uptake (including multi-limitation of algal growth by nutrients). We highlight, that in many ecosystem models, phytoplankton processes are still described more or less empirically, mainly due to a lack of biochemical knowledge, or if a mechanistic formulation exists, the parameters are often difficult to assess experimentally. As a result of this investigation, a preliminary structure for a generic phytoplankton model is delivered in the last section of this paper. This model includes a mechanistic representation of photosynthesis/photoinhibition based on photosystem II status, as well as new formulations for photoacclimation and dissolved organic matter exudation processes. The model sensitivity analysis with regard to its parameters and a comparison with chemostat experimental data are presented in a companion paper [Baklouti, M., Faure, V., Pawlowski, L., Sciandra, A., 2006. Investigation and sensitivity analysis of a mechanistic phytoplankton model implemented in a new modular numerical tool (Eco3M) dedicated to biogeochemical modelling. Progress in Oceanography]. Finally, this new class of multi-element, multi-species phytoplankton models will provide the basis for future studies on ecosystem modelling. 相似文献
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Lawrence W. Harding Jr Blanche W. Meeson Thomas R. Fisher Jr 《Estuarine, Coastal and Shelf Science》1986,23(6)
Chesapeake Bay is a large and productive estuary that has received close scrutiny in recent years because of indications that its water quality and biota have been damaged by man's activities. Data on primary production for the estuary as a whole, however, are surprisingly sparse. We describe here the distribution of photosynthetic carbon assimilation by phytoplankton in Chesapeake Bay, and relate productivity patterns to hydrographic characteristics of the estuary. Between March 1982 and April 1983, a series of four cruises was conducted on Chesapeake Bay, and two cruises on the urbanized Delaware Bay for comparison. The upper Chesapeake and Delaware were highly turbid with high concentrations of suspended particulate matter and dissolved inorganic nutrients. Low chlorophyll concentrations were usually found in these areas of high turbidity, despite the abundance of nutrients, suggesting light limitation. Application of Wofsy's (1983) model of phytoplanton growth confirmed this suggestion. Chlorophyll and productivity maxima usually occurred seaward of the turbidity maxima where light penetration increased and suffient nutrients were present to support active phytoplankton growth. Further seaward of the chlorophyll maxima in the Chesapeake, the photic zone depth increased, concentrations of nutrients decreased, and phytoplankton biomass decreased, suggesting that nutrient availability, rather than light, controlled phytoplankton growth in the lower portion of the estuary. In contrast to the Chesapeake, Delaware Bay was more turbid, had generally higher nutrient concentrations, and was lower in phytoplankton productivity. The chlorophyll maxima and region of rapid phytoplankton growth occurred further toward the lower estuary and shelf regions in Delaware Bay because the high turbidity extended further seaward. Nutrients were never depleted at the shelf end of the estuary sufficiently to retard phytoplankton growth. Photosynthesis-irradiance (P-I) curves from simulated in situ and constant intensity incubations showed a strong correlation of the light-limited slope (aB) with the light-saturated rate (
) on each cruise. Spatial variations in
corresponded to patterns of phytoplankton abundance, as did integral production (PP) and carbon-based growth rates (μC, μm), and photosynthetic parameters varied significantly with temperature. 相似文献