首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
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 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   

2.
Comprehensive surveys were conducted in the Kocebu deep seamount and the M4 shallow seamount in the Western Pacific Ocean in March 2018 and May 2019,respectively.The distributions of nutrients in euphotic zone of the two seamount-areas were revealed,and the causative controlling factors were analyzed.Results show that the vertical distribution of nutrients in the two seamount-areas accorded with the general law of the oligotrophic ocean.The concentrations of NO_3-N,PO_4-P,and SiO_3-Si generally increased gradually with the increase of water depth,and they were extremely low in water layers within100 m.The area of high N02-N concentration well agreed with the Deep Chlorophyll Maximum Layer.On the other hand,the distribution of water masses and phytoplankton and hydrological conditions in the two seamount-areas were different,resulting in lower concentrations of NO_3-N,PO_4-P,and SiO_3-Si in the water layers below 100 m in the Kocebu seamount area than those in the M4 seamount area.In addition,N02-N was affected by the distribution of phytoplankton,and distributed mainly in the water layers of 150 and100 m.There was upwelling in the euphotic zone of M4 seamount area,causing accumulations of nutrients and phytoplankton around the seamount,forming a "seamount effect";however,no such an effect was found in Kocebu seamount area.Affected by the composition of biological community and the "seamount effect",the nitrogen limitation in the M4 seamount area was not significant,and the dissolved inorganic nitrogen(DIN):PO_4-P and SiO_3-Si:DIN were closer to the Redfield ratios.  相似文献   

3.
Incubation experiments are carried out to study the exchange rates of dissolved inorganic nutrients including silicate, phosphate, ammonium, nitrite, and nitrate (vSiO3-Si, vPO4-P, vNH4-N, vNO2-N and vNO3-N) at the sediment-water interface in the Jiaozhou Bay. Major factors influencing the exchange rates are discussed in detail, which include the dissolved inorganic nutrient concentrations in porewater (Cpw), water and clay contents, and grain size of the sediments (CH2O, Cclay and GSsed). The results may provide insight into the dynamics of nutrient transport and the environmental capacity of nutrients in Jiaozhou Bay, and should be beneficial to solving the problems caused by excessive nutrient input this area.  相似文献   

4.
Water samples were collected at 20 sites on 4 occasions in 2009(twice in May,and once in both August and November) along the Jiulong River,South China to examine how nutrient inputs from the Jiulong River could affect the nutrient status of the Xiamen Water.Samples were analyzed for nitrite(NO2-N),nitrate(NO3-N),ammonium(NH4-N),phosphate(PO4-P),silicate(SiO3-Si),salinity,and temperature,to determine the nutrient and trophic status of the river.The results indicate that nutrients are derived mainly from river runoff.NO3-N was the main form of DIN in most parts of the river.In addition,NO3-N,DIN,and SiO3-Si behave conservatively.There is a surplus of DIN and SiO3-Si in the river,and PO4-P is a limitation on phytoplankton growth.The concentration of DIN is typically above 0.60 mg/dm3,and higher than 1.00 mg/dm3in most parts of the river.The concentration of PO4-P is typically above 0.02 mg/dm3,while the concentration of SiO3-Si is higher than 1.00 mg/dm3.Between 2003 and 2008,samples were collected 3 times per year(May,August and November) at 27 sites in the Xiamen Water and analyzed for NO2-N,NO3-N,NH4-N,PO4-P,salinity,and temperature.We discovered that the Jiulong River was the key source of DIN into the Xiamen Water,but not PO4-P,indicating the reason of the N/P molar ratio imbalance in the Xiamen Water.In the future,the effects of high DIN concentrations on the phytoplankton communities and marine ecosystems of the Xiamen Water shall be studied.  相似文献   

5.
To gain a better understanding of water quality and eutrophication, we investigated the seasonal and spatial distribution of water quality at 17 stations in the Guangzhou Sea Zone (GZSZ). Nutrients, chlorophyll-a (Chl-a), salinity, chemical oxygen demand, and other physical and chemical parameters were determined in February, May, August and October from 2005 to 2007. The concentrations showed ranges of 93.2–530.4 μmol/L for dissolved inorganic nitrogen (DIN), 0.62–3.16 μmol/L for phosphate (PO4-P) and 50–127 μmol/L for silicate (SiO3-Si). The results indicated that DIN was strongly influenced by domestic sewage coming from Guangzhou City and NO3-N was the main form of DIN in most areas, while concentrations of phosphate and silicate were generally controlled by Pearl River runoff, land-based sources along the land or islands, and algae assimilation. N/P ratios were very high in both dry season and wet season, and varied from 57 to 667, suggesting that P was potentially the most limiting nutrient in the GZSZ. The concentrations of Chl-a were 3–96 μg/L, and were highly correlated with the distribution characteristics of COD. The concentrations of nutrients have increased over the past two decades (1982–2007). This means it is necessary to control the input of nutrients to the GZSZ, especially that of phosphate.  相似文献   

6.
Sediments and surface water were sampled in a tide flat in the Huiquan Bay, Qingdao, China in January 2004 to simulate the exchange of NH4-N/NO3-N/PO4^3- between sediments and surface water. A working system was designed with which samples were shaken at 60, 120 and 150 revolutions per minute （r/min）. Experiment results show that NH4-N concentration in water at shaking rate of 60 r/min decreased gradually, while at 120 r/min increased gradually. In resuspension, fine-grained sediments contributed most NH4-N to the seawater, followed by medium-grained and coarse-grained sediments. The NO3-N concentration in water had a negative relation with the shaking rate; the medium-grained sediments contributed more NO3-N to seawater than the coarse- and fine-grained sediments. The PO4^3- concentration is positively related with the shaking rate, the fine-grained sediments were the main N and P contributor to the seawater, followed by medium- and coarse-grained sediments.  相似文献   

7.
Sediments and surface water were sampled in a tide flat in the Huiquan Bay, Qingdao, China in January 2004 to simulate the exchange of NH4-N/NO3-N/ PO 43- between sediments and surface water. A working system was designed with which samples were shaken at 60, 120 and 150 revolutions per minute (r/min). Experiment results show that NH4-N concentration in water at shaking rate of 60r/min decreased gradually, while at 120r/min increased gradually. In resuspension, fine-grained sediments contributed most NH4-N to the seawater, followed by medium-grained and coarse-grained sediments. The NO3-N concentration in water had a negative relation with the shaking rate; the medium-grained sediments contributed more NO3-N to seawater than the coarse-and fine-grained sediments. The PO 43- concentration is positively related with the shaking rate, the fine-grained sediments were the main N and P contributor to the seawater, followed by medium-and coarse-grained sediments.  相似文献   

8.
Benthic nutrient recycling in shallow coastal waters of the Bohai Sea   总被引：3，自引：0，他引：3  
Sediment-water fluxes of N and P species in the Bohai Sea were investigated in September-October 1998 and April-May 1999. The benthic fluxes of nutrient species were determined by incubating sediment core samples with bottom seawater bubbled with air or nitrogen. NO^-2,NH4, dissolved organic nitrogen (DON) and phosphorus (DOP), total dissolved nitrogen (TDN) and phosphorus (TDP), and PO4^3- showed a net exchange flux from seawater to sediment, while NO^-3, dissolved inorganic nitrogen (DIN) and SiO3^2- were released from sediment to seawater in the Bohai Sea. Sediment-water nutrient exchange increases DIN and reduces the phosphorus load in the Bohai Sea. The release of silicate from sediment to overlying seawater reduces potential silicate limitation of primary production resulted from decrease of riverine discharge.The exchange flux of nutrients showed no obvious seasonal variation. The present study showed that the concentrations and composition of nutrients in the water column were affected by suspended sediment, and that not all the exchangeable phosphate in sediment could be released via sediment resuspension.  相似文献   

9.
Based on field data for nutrients collected on the continental shelf of the East China Sea (ECS) during summer 2006, the structure and variations of nutrients in every water mass related to the Taiwan Warm Current (TWC) were analyzed. The supplementary effect of nutrient of upwelling on harmful algal blooms (HABs) in the ECS was also estimated, based on upwelling data. Then the maintenance contribution of nutrient of upwelling to HABs was assessed. The results showed that N/P ratio is fairly low in both surface and deep layers of the TWC, which possibly controls nutrient structure of the HABs-frequently-occuring areas. In upwelling areas, the rate of phosphate (PO4-P) uptake exceeds that of nitrate (NO3-N) of the TWC. The TWC may relieve PO4-P limitation during the process of HABs. Furthermore, upwelling plays an important role in providing nutrients to HABs. After estimating nutrient fluxes (NO3-N, PO4-P, SiO3-Si) in the upwelling areas along a typical section (S07), the results showed that the nutrient uptake rate is the greatest at 10–20 m below euphotic zone, sustaining the ongoing presence of HABs. The uptake rate of PO4-P is the highest among dissolved inorganic nutrients. Therefore, upwelling is most likely the main source of PO4-P supply to HABs.  相似文献   

10.
Nutrient and eutrophication characteristics of the Dongshan Bay,South China   总被引：1，自引：0，他引：1  
We recorded NO 3-N, NO 2-N, NH 4-N, PO 4-P, SiO 3-Si, salinity, and temperature data at 10 stations in the Dongshan Bay in May, June, July, August, October, and November 2008, analyzing nutrient and eutrophication characteristics. The mean concentration of dissolved inorganic nitrogen(DIN) was 0.30–0.40 mg/dm 3; generally, NO 3-N was the main form in most areas. The mean concentrations of PO 4-P and SiO 3-Si were 0.040–0.060 mg/dm 3 and 1.00–1.50 mg/dm 3, respectively. We proved that the majority of the SiO 3-Si in the Dongshan Bay came from the Zhangjiang River, with some coming from the Bachimen Strait. DIN originated from both the Zhangjiang River and the Bachimen Strait. Most PO 4-P originated from the Bachimen Strait, and some came from the Zhangjiang River. We found that P was an overall limiting factor to the phytoplankton community in most of the Dongshan Bay, and that Si and N were in surplus. However, near the Bachimen Strait Si became a limiting factor, especially for diatoms, while P and N were in comparative surplus. We used a potential eutrophication assessment method to analyze eutrophication, and showed that the most serious eutrophication occurred near the Zhangjiang River estuary and near the Bachimen Strait. In 2008, DIN levels were four times higher than that in 1988; PO 4-P levels were threefold higher, while SiO 3-Si was approximately double. Dissolved nutrients increased between 1988 and 2008. DIN increased at the greatest rate comparing to PO 4-P and SiO 3-Si, thus the N/P and N/Si mol ratios increased. Further studies on the effects of high DIN concentrations on the phytoplankton communities and marine ecosystems of the Dongshan Bay are needed.  相似文献   

11.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｐｒｏｄｕｃｔｉｏｎｏｆｐｈｙｔｏｐｌａｎｋｔｏｎｉｓｔｈｅｆｉｒｓｔｔａｃｈｅｉｎｔｈｅｐｒｏｄｕｃｔｉｏｎｂｙｍａｒｉｎｅｏｒｇａｎｉｓｍｓａｎｄｉｎｔｈｅｍａｒｉｎｅｆｏｏｄｃｈａｉｎ .Ｋｎｏｗｌｅｄｇｅｏｆｐｒｉｍａｒｙｐｒｏｄｕｃｔｉｏｎｉｎｍａｒｉｎｅｗａｔｅｒｓｉｓｐｒｅｒｅｑｕｉｓｉｔｅｆｏｒｅｘｐｌｏｉｔａｔｉｏｎａｎｄｍａｎａｇｅｍｅｎｔｏｆｔｈｅｏｃｅａｎ’ｓｌｉｖｉｎｇｒｅｓｏｕｒｃｅｓ.Ｔｈｅｐｒｉｍａｒｙｐｒｏｄｕｃｔｉｏｎｉｎｍａｒｉｎ…  相似文献   

12.
以中国生态系统研究网络CERN长武王东沟实验站的坡耕地和塬耕地为供试土壤,研究了黄土高原沟壑塬区旱耕地原状土壤氮素迁移和时空变异。结果表明:耕作土壤NO3--N为23.1~33.8 mg/kg,NH4+-N为0.23~0.50mg/kg,DOC为9.17~13.38 mg/kg,P为0.18~0.23 mg/kg;坡耕地和塬耕地的NO3--N和NH4+-N主要集中在0~20 cm的上层土壤,中下层土壤NO3--N和NH4+-N起源于上层淋溶迁移和累积;高含量时养分淋溶溶出呈指数衰减型;NO3--N、NH4+-N、DOC向下层的迁移塬耕地慢于坡耕地。  相似文献   

13.
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   

14.
Sishili Bay is the most important aquiculture and tourism area for the city of Yantai, China; however, red tides occurred frequently and have caused huge economic losses in this bay in recent years. To gain a better understanding of the local ecological environments in the bay, we conducted this research between 2003 and 2008 to analyze variations in nutrients and chlorophyll (chl-a) during high frequency red tide period (May to September). The results show that the chl-a concentration increased from 2.70 in 2003 to 7.26 mg/m3 in 2008, while the concentration of total inorganic nitrogen (TIN) and silicate (SiO3-Si) increased lineally from 5.18 and 1.45 μmol/L in 2003 to 18.57 and 9.52 μmol/L in 2008, respectively, and the annual phosphate (PO4-P) varied between 0.15 and 0.46 μmol/L. Special attention was given to a red tide in August 2007 occurred when water temperature was high and nutrient concentrations increased sharply because of a heavy rainfall. Overall, the results show the P limitation in Sishili Bay, and reveal that red tides were caused by eutrophication from terrestrial inputs and local warm weather, particularly during rainy periods. Therefore, to control red tide, greater efforts should be made to reduce sewage discharges into Sishili Bay, particularly during rainfall seasons.  相似文献   

15.
测试了由紫外线杀菌器、臭氧发生器、蛋白质分离器和生物过滤器4部分构成7种不同组合的水处理系统的水处理效果,探讨了各部分在水处理中的作用。结果表明,开启整套系统对砂滤水三次处理时,系统对NH4+-N、NO2--N、普通细菌、弧菌去除作用明显,去除率分别为41.92%、53.58%、94.59%和100%,且能明显增加水体溶解氧含量,对pH的影响不明显。  相似文献   

16.
用单因子对比实验和正交实验的方法研究了氮、磷、铁和硅对简单双眉藻生长的影响。结果表明:简单双眉藻对于硝酸钠和尿素均能很好地利用,其相对生长常数无显著差异,对柠檬酸铁和三氯化铁的利用亦无显著差异,FeC6H5O7-Fe的适宜浓度为0.1～0.5mg/L;Na2SiO3-Si的适宜浓度为0.8～1.6mg/L。正交实验表明,简单双眉藻氮、磷、铁、硅的最佳浓度(mg/L)配比为6.6∶0.66∶0.1∶0.4。  相似文献   

17.
Water samples were collected in 120 stations in the Bohai Sea of China to analyze the distribution of dissolved nutrients and assess the degree of eutrophication in August 2002. The result shows that the average concentration of DIN increased and the PO4-P concentration sharply decreased compared to the previous data of corresponding period. The high concentrations of DIN and PO4-P occurred in coastal waters, especially in the bays and some river estuaries, while the high concentrations of SiO3-Si in the surface and middle depth occurred in the central area of the Bohai Sea. The average ratio of DIN/ PO4-P was much higher than the Redfield Ratio (16:1). Apparently, PO4-P was one of the limiting nutrient for phytoplankton growing in the sea. The average concentrations of DON and DOP were higher than their inorganic forms. The results of eutrophication assessment show that 22.1% of all stations were classified as violating the concentration levels of the National Seawater Quality Standard (GB 3097-1997) for DIN and only 3.9% for PO4-P. The average eutrophication index in the overall area was 0.21±0.22 and the high values occurred in Bohai Bay, Liaodong Bay and near the Yellow River estuary. This means that the state of eutrophication was generally mesotrophic in the Bohai Sea, but relatively worse in the bays, especially some river estuaries.  相似文献   

18.
Two cruises for multi-discipline investigation were conducted in October and November,1998 in Daya Bay to collect: (1) samples from five levels including sea-surface microlayer (SML), subsurface (SSL), surface, body (mid-column) and bottom water; and (2) observational data on chlorephylla and notri-eras, and important factors such as turbidity, BOD, COD, TN, TP and phytoplanklon. Results showed that there was no enrichment of chlorophyll-a in the SML, but quite notable enrichment of some organic matter and nutrients. Compared with the findings in earlier researches, PO4^-P and SiO3-Si have decreased, and the N/P ratio has increased obviously to even more than 100 in the SML. It is concluded preliminarily that PO4-P and SiO3-Si mainly determine phytoplankton growth in Daya Bay at present.  相似文献   

19.
The purification law of nitrogen in Deyeuxia angustifolia,Carex lasiocarpa and Deyeuxia angustifo-lia-Carex lasiocarpa combined wetland systems in the Sanjiang Plain,China was studied by field simulation experi-ment.The results indicate that the removal rates of TN,NH4+-N and NO3--N in above three types of wetlands present an obvious logarithm growth trend along with the time.There are evident removal effects for NH4+-N and NO3--N in water bodies of wetlands after the 30th day of experiment,with the removal rates over 80.0%,but the removal rate of TN is slightly low,being 63.1%-74.3%.NO3--N is most quickly removed by the combined wetland,and NH4+-N by Deyeuxia angustifolia wetland.The removal speeds of TN by the three wetland systems are comparatively slow,of which the Deyeuxia angustifolia wetland is the fastest.In consideration of plant growth season,Deyeuxia angustifolia wetland has much more practical application value in purifying nitrogen.These results can provide references for the study on the purification function of wetlands and the control of non-point source pollution in Northeast China.  相似文献   

20.
在实验室条件下研究半叶马尾藻对不同浓度N、P以及不同化合态N的吸收速率。结果显示:不同浓度N、P下,半叶马尾藻对N、P的吸收速率差异有统计学意义(P0.05);半叶马尾藻对N、P的吸收速率随N、P浓度的升高而增加,最大吸收速率出现在N为200μmol/L、P为20μmol/L时,分别为2.397和0.229μmol·g-1·h-1;不同氮磷比条件下,半叶马尾藻对N、P的最大吸收速率出现在氮磷比为10时,在氮磷比为1~30范围内,氮磷比对半叶马尾藻吸收N、P速率的影响有统计学意义(P0.05);不同化合态N对半叶马尾藻吸收N、P速率的影响有统计学意义(P0.05),当NH4+-N和NO3--N共存时,半叶马尾藻对这2种化合态氮可同时吸收利用,各处理组间,对总无机N的吸收速率差异有统计学意义(P0.05),在c(NO3--N)/c(NH4+-N)为2∶1和1∶2处有两个峰值,分别为2.036、1.862μmol·g-1·h-1,对P的最大吸收速率均出现在c(NO3--N)/c(NH4+-N)值为2∶1时,为0.206μmol·g-1·h-1。因此,在粤西沿海半叶马尾藻在消除养殖水域营养盐、防治海水富营养化方面有很大优势。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

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